Interior graphic standards

01_9780470889015_ffirs.qxd:WILEY 9/19/11 10:02 AM Page I INTERIOR GRAPHIC STANDARDS STUDENT EDITION 01_9780470889015_ffirs.qxd:WILEY 9/19/11 10:02 AM Page II 01_9780470889015_ffirs.qxd:WILEY 9/19/11 10:02 AM Page III INTERIOR GRAPHIC STANDARDS STUDENT EDITION SECOND EDITION CORKY BINGGELI, ASID EDITOR-IN-CHIEF T H E M AG N U M G R O U P I L L U S T R AT O R JOHN WILEY & SONS, INC. 01_9780470889015_ffirs.qxd:WILEY This book is printed on acid-free paper. 9/19/11 10:02 AM Page IV ∋ Copyright © 2012 by John Wiley & Sons, Inc. 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Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. For more information about Wiley products, visit our web site at www.wiley.com. Library of Congress Cataloging-in-Publication Data: Interior graphic standards / Corky Binggeli, editor-in-chief. — 2nd ed. p. cm. — (Ramsey/sleeper architectural graphic standards series ; 21) Rev. ed. of: Interior graphic standards / Maryrose McGowan, Kelsey Kruse. © 2003. Includes index. ISBN 978-0-470-88901-5 (pbk.), ISBN 978-1-118-09933-9 (ebk), ISBN 978-1-118-09934-6 (ebk), ISBN 978-1-118-09935-3 (ebk), ISBN 978-1-118-13023-0, ISBN 978-1-118-13024-7 (ebk) 1. Building—Details—Drawings. 2. Building—Details—Drawings—Standards. I. Binggeli, Corky. II. TH2031.I55 2012 729—dc22 2011013755 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 01_9780470889015_ffirs.qxd:WILEY 9/19/11 10:02 AM Page V ACKNOWLEDGMENTS JOHN WILEY & SONS, INC. AMANDA L. MILLER VICE PRESIDENT AND PUBLISHER KATHRYN MALM BOURGOINE ACQUISITIONS EDITOR LAUREN POPLAWSKI EDITORIAL PROGRAM COORDINATOR KERSTIN NASDEO PRODUCTION MANAGER JUSTIN MAYHEW ASSOCIATE MARKETING DIRECTOR DESIGN/PRODUCTION BRUCE MAU DESIGN, INC. DESIGNER LUCINDA GEIST COMPOSITOR FOXXE EDITORIAL COPYEDITOR, PROOFREADER IGS EDITORS CORKY BINGGELI, ASID EDITOR-IN-CHIEF PATRICIA GREICHEN GRAPHICS EDITOR, INTERIOR GRAPHIC STANDARDS ILLUSTRATOR THE MAGNUM GROUP LUCKY BALARAMAN N. RAMGOPAL V. ANANDARAJAN R. KAMALATHASAN V. KARTHIKEYAN IGS STUDENT EDITION ADVISORY BOARD BARBARA ANDERSON ESMA BURÇIN DENGIZ ELLEN FISHER MONICA LETOURNEAU LOIS WEINTHAL LINDA ZIMMER CONTRIBUTORS ROBERT D. ABERNATHY MIA ALWEN AMERICAN GAS ASSOCIATION AMERICAN IRON AND STEEL INSTITUTE AMERICAN SANITARY PARTITION CORPORATION AMERICAN SOCIETY OF PLUMBING ENGINEERS ROBERT E. ANDERSON, AIA ARCHITECTURAL WOODWORK INSTITUTE ARCHITECTURAL WOODWORK MANUFACTURERS ASSOCIATION OF CANADA WILLIAM R. ARNQUIST, AIA ASSOCIATED SPACE DESIGN ATLAS ELEVATOR COMPANY CHARLES M. AULT SARAH BADER TOM BADER, AIA DAVID BALLAST, FAIA FAITH BAUM, AIA, IIDA BAUMGARDNER ARCHITECTS ERIC K. BEACH CHRISTINE BEALL, NCARB, CCS KIM A. BEASLEY, AIA TEDD BENSON BETSY BERG, MSHA BFS ARCHITECTURAL CONSULTING AND INTERIOR DESIGN JOHN BIRCHFIELD JAN BISHOP, AIA LELAND D. BLACKLEDGE, AIA MICHAEL L. BLANKENSHIP JOAN BLUMENFELD BLYTHE + NASDIN ARCHITECTS, LTD. JEFFREY E. BOLLINGER WARREN D. BONISCH, PE PAUL BONSALL RAYMOND C. BORDWELL, AIA SARAH BRENNARD STEVEN R. BREUER, AIA BROSSO, WILHEIM & MCWILLIAMS PETER BROWN, AIA BEN BRUNGRABER, PHD BUILDING STONE INSTITUTE ABIGAIL CANTRELL JOHN CARMODY CARPET AND RUG INSTITUTE TIMOTHY W. CAPE, CTS-D CHRISTOPHER CAPOBIANCO CASTING DESIGNS, INC. REX CAULDWELL TAMMY CAVIN CERAMIC GLAZED MASONRY INSTITUTE CHAIRMASTERS, INC. WINNIE CHENG CINI-LITTLE INTERNATIONAL, INC. JANE CLARK, AIA DAVID S. COLLINS, FAIA BRIAN COOPER, AIA DAVID COOPER, AIA DEAN COX, AIA CUTLER MANUFACTURING CORPORATION CHRIS CZENSZAK JOSHUA DACHS THOMAS D. DAVIES JR., AIA TAMA DUFFY DAY SONYA DUFNER LARRY O. DEGELMAN, PE J. T. DEVINE, AIA DFB SALES MAYURA DHUME JASON DICKERSON M. DIXON DARREL DOWNING NADER DUBESTANI, PE JOHN C. EAGAR, PE RICHARD EISNER JOHN ELLEDGE, AIA ANNICA S. EMILSSON KATHIE ENGELBRECHT EDWARD R. ESTES JR. JENNIE EVANS, RN KATRINA EVANS ROBERT T. FAASS FACING TILE INSTITUTE JOSEPH FAIN DAN FENTON, PE DUANE FISHER FLACK & KURTZ DOUGLAS FLANDRO RUSSELL S. FLING, PE ROBERT P. FOLEY, PE MARK FORMA KENNETH D. FRANCH, PE, AIA MICHAEL FRANKEL, CIPE SIDNEY FREEDMAN PETER H. FRINK AL GERHART FRANK GIESE ERIC GLASTIER ANTHONY GOLEBIEWSKI, AIA MEGAN GOVER, IIDA RON GOVER, AIA GRACE CONSTRUCTION PRODUCTS ALFRED GREENBERG, PE PETER GREENBERG VIRGINIA A. GREENE TODD GRITCH, FAIA WALTER T. GRONDZIK, PE HENRY GROSSBARD HELMUT GUENSCHEL, INC. JANA GUNSUL, IIDA KAREN GUNSUL, AIA JEFF HABERL, PE GULZER HAIDER BECCA HALL GARY A. HALL NELSON HAMMER, RLA KELLY HANNON JANE HANSEN, AIA LEISA HARDAGE, AIA JENNIE HARDEN SUSAN HARDIMAN DANIEL F. C. HAYES, AIA HAYNES WHALEY ASSOCIATES DEBBIE HEITZMAN CARL HENSCHEL DEBORAH HERSHOWITZ GREG HEUER CODY HICKS JOHN D. HILBERRY, AIA JOHN L. HOGSHEAD, AIA TOM HORTON REGINALD D. HOUGH, FAIA RICHARD F. HUMENN, PE ISD INCORPORATED D. JACKMAN HUGH NEWELL JACOBSEN, FAIA 01_9780470889015_ffirs.qxd:WILEY 9/19/11 10:02 AM Page VI VI NORMAN JAFFE, FAIA NATASA JELIC DAVID W. JOHNSON JIM JOHNSON CHRISTOPHER M. JOHNSTON, PE JACQUELINE JONES JRS ARCHITECT KARLSBERGER AND COMPANIES JOHN F. KAULBACH, AIA PHILIP KENYON ALEXANDER KEYES TREY KLEIN, AIA JOHN H. KLOTE MARCIA KNIGHT, RID KNOLL TEXTILES FREDERICK C. KRENSON, AIA KROMMELHOEK/MCKEOWN AND ASSOCIATES KELSEY A. KRUSE, AIA SUNYOUNG KWON LAUCKGROUP GRACE S. LEE TOM LENSMENT JOHN A. LESIRE, AIA KAREN K. LINDBLAD JAMES D. LLOYD NICK LOOMIS STEPHEN LUK JOHN C. LUNSFORD, AIA STEPHEN MARGULIES, IES, IALD MARMON MOK PARTNERSHIP JASON MARTINEZ ROBERT MARTINO MASTERSPEC MAYTAG CORPORATION CAMIE MAZE, AIA MARK J. MAZZ, AIA SCOTT A. MCALLISTER, AIA MCCAIN MCMURRAY, ARCHITECT KEITH MCCORMACK, CCS, CSI KELLIE MCCORMICK, ASID TIMOTHY B. MCDONALD KIM MCGHEE NOREEN MCGING, RNC JESS MCILVAIN, AIA MCKEY PERFORATING COMPANY JEFFREY MEESE, AIA TED MILLIGAN WALTER MOBERG MARGERY MORGAN MULTI-HOUSING LAUNDRY ASSOCIATION CHRISTOPHER MUNDELL, AIA M. KITTY MYERS, AIA TANYA NACHIA NATIONAL FIRE PROTECTION ASSOCIATION NATIONAL KITCHEN AND BATH ASSOCIATION NATIONAL TERRAZZO AND MOSAIC ASSOCIATION, INC. NATIONAL WOOD FLOORING ASSOCIATION DONALD NEUBAUER, PE ELIZABETH NIEDZWIECKI, AIA OBRIEN-KILGORE, INC. ANITA RUI OLDS SHARON PARKS DEBAJYOTI PATI, FIIA RICHARD H. PENNER REY PEREZ LAWRENCE G. PERRY, AIA CHARLES PETERSON ARTHUR J. PETTORINO, AIA SOYPLOY PHANICH JAMES E. PHILLIPS, AIA BOB PIELOW VALENTIN PILYAVSKIY POLYSONICS R. 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CHARLES B. TOWLES, PE BRIAN E. TRIMBLE MICHAEL UFER, AIA JEFFREY R. VANDEVOORT DAVE VINCENT, AIA RICHARD J. VITULLO, AIA WALTER HART ASSOCIATES, AIA GEORGE M. WHITESIDE III, AIA JOSEPH A. WILKES WILKINSON COMPANY, INC. KENT WONG WOODWORK INSTITUTE ROBERT WRIGHT, FASID GARY YABUMOTO JAN YEAGER JOHN I. YELLOTT, PE MERVE YONEYMAN TAM YOUNGCHAROEN 02_9780470889015_ftoc.qxd:WILEY 9/19/11 10:05 AM Page VII CONTENTS PREFACE . . . xi SECTION 1 DESIGN PRINCIPLES AND PROCESS . . . 1 CHAPTER 1 ENVIRONMENTAL AND BEHAVIORAL ISSUES Human Factors 3 Anthropometrics and Ergonomics 3 Human Behavior 10 Wayfinding 11 Mapping 11 Wayfinding and Age 11 Signage and Wayfinding Clues 12 CHAPTER 2 ACOUSTICAL PRINCIPLES Basics of Acoustical Design 13 Sound 13 Frequency 13 Sound Absorption Properties of Materials 13 Room Acoustics 14 Properties of Sound 14 Use of Sound-Absorptive Materials 14 Sound Transmission 15 Transmission Loss 15 Noise Reduction 15 Sound Isolation 15 Impact Noise Reduction 15 Sound Control 17 CHAPTER 3 ACCESSIBLE DESIGN BASICS Accessibility 18 Definitions 18 Accessibility Standards Terms 18 ADA and FHAA Design Requirements 18 Knee and Toe Clearances 19 Reach Limits 20 Protruding Objects 21 Accessible Routes 22 Components of Accessible Routes 22 Location of Accessible Routes 22 Floor and Ground Surfaces 22 CHAPTER 4 SUSTAINABLE DESIGN BASICS Sustainable Design Principles 24 Depletion of Natural Resources 24 Climate Change 24 Principles 25 Design Considerations 25 Sustainability Strategies 25 Energy 25 Lighting and Daylight 25 Water 25 Sustainable Materials 25 Indoor Air Quality 26 Environmental Quality Terms 26 Sick Building Syndrome 26 Personal Control 26 Interior Rating Systems and Certifications 27 U.S. Green Building Council 27 LEED Rating System 27 CHAPTER 5 DESIGN BASICS Evidence-Based Design 29 Computational Research 29 Social Science Research 29 Physical and Natural Science Research 29 Building Codes 29 Codes and Regulations Affecting Interiors 29 International Building Code Provisions 30 Programming 33 Programming Process 33 Contract Documents 34 Contract Documents for Commercial Interiors 34 Furniture, Furnishings, and Equipment Contracts 34 Detailing Concepts 35 Construction Specifications 37 Computing Technologies 38 Computer-Aided Design and Building Information Modeling 38 Integrated Project Delivery 38 Virtual Collaboration 38 Future Developments 39 Digital Fabrication 39 SECTION 2 BUILDING ELEMENTS . . . 41 CHAPTER 6 BUILDING STRUCTURE AND SHELL Substructure 43 Wall Foundations 43 Subgrade Enclosures 43 Slabs on Grade 44 02_9780470889015_ftoc.qxd:WILEY 9/19/11 10:05 AM Page VIII VIII Superstructure 45 Seismic Considerations 45 Superstructure Framing 46 Floor Construction Assemblies 57 Wood Floor Framing 57 Steel Joist Floor Framing 59 Floor Decks and Slabs 60 Roof Construction 62 Roof Types and Framing 62 Shop-Fabricated Wood Trusses 63 Glue-Laminated Construction 64 Roof Decks, and Slabs 65 Attic Ventilation 66 Stairs and Ramps 66 Stairs 66 Handrails, Balustrades, and Guards 69 Ramps 78 Exterior Vertical Enclosures 79 Exterior Wall Weather Barriers 79 Exterior Enclosure Walls 80 Roof Windows and Skylights 87 CHAPTER 7 INTERIOR CONSTRUCTION Fire Resistive Construction 89 Fire-Retardant Wood Treatment 89 Fire-Resistance-Rated Assemblies 89 Fire-Resistance-Rated Openings 91 Board Fire Protection 93 Penetration Firestop Systems 93 Seismic Considerations 93 Basic Seismic Design 93 Seismic Detailing for Designers 94 Interior Construction Components 95 Gypsum Board Assemblies 95 Concrete Masonry Units 114 Architectural Concrete 116 Stone Walls 117 Glass Unit Masonry 118 Prefabricated Partitions 120 Windows and Glazing 125 Interior Doors 131 Entrances and Vestibules 148 Raised Floor Construction 148 Thermal and Moisture Protection 149 Interior Finishes 150 Interior Specialties 150 Wall Finish Requirements 162 Integral Wall Finishes 163 Wood Wall Finishes 166 Tile Wall Finishes 175 Metal Wall Finishes 181 Wall Surface Coverings 183 Paints and Coatings 188 Floor Design Considerations 190 Hard Flooring 191 Wood Flooring 198 Resilient Flooring 201 Resilient Flooring Installation 204 Carpet, Carpet Tile, and Mats 205 Ceilings 213 Building Services 223 Conveying Systems 223 Plumbing Systems 231 Mechanical Systems 247 Fire Protection Systems 254 Electrical Systems 259 Lighting 265 Communications Systems 272 Security Systems 280 CHAPTER 8 EQUIPMENT AND FURNISHINGS Equipment 283 Toilet and Bath Equipment 283 Vending Equipment 285 Personal Care Equipment 286 Laundry Facilities 288 Teller and Service Equipment 290 Cleaning and Recycling Equipment 292 Furnishings 292 Furnishing Contracts and Tests 292 Textiles for Interior Furnishings 294 Cabinetry and Casework 299 Countertops 306 Art and Accessories 313 Furniture 315 Plantings 318 Window Treatments 321 CHAPTER 9 INTERIOR PROJECT TYPES Commercial Spaces 326 Offices 326 Conference Rooms 343 Residential Spaces 349 Kitchens 349 Furnishings and Equipment 354 Residential Lighting 357 Visitability 358 Aging in Place 359 Continuing Care Retirement Communities 365 Healthcare Facilities 369 Inpatient Hospitals 369 Ancillary Departments 372 Healthcare Casework 379 Healthcare Furniture 381 02_9780470889015_ftoc.qxd:WILEY 9/19/11 10:05 AM Page IX IX Retail Spaces 382 Types of Retail Spaces 382 Fixture Placement 382 Retail Equipment 383 Retail Lighting 383 Performance Spaces 419 Planning Criteria 419 Performance Equipment 421 Hospitality Spaces 384 Hotels 384 Restaurants 390 Museums 421 Museum Design Considerations 421 Museum Exhibit Casework 421 Museum Lighting 423 Museum Security 425 Educational Facilities 402 Early Childhood and Kindergarten 402 Elementary, Middle, and Junior High Schools 404 High Schools 405 Lecture Halls and Auditoriums 410 Libraries 413 Athletic and Fitness Spaces 425 Courts, Alleys, and Rinks 425 Gymnastics 426 Table Sports and Darts 427 Fitness Spaces 428 Saunas and Steam Rooms 430 Animal Care Facilities 431 General Design Concept 431 Animal Housing 431 Adoption Facility 434 Existing Building Interiors 435 Historic Preservation, Restoration, and Adaptive Reuse 435 Existing Hazardous Materials 436 Recycling Construction and Demolition Waste 438 APPENDIX Classical Interior Architectural Elements 439 GLOSSARY . . . 449 INDEX . . . 455 02_9780470889015_ftoc.qxd:WILEY 9/19/11 10:05 AM Page X 03_9780470889015_flast.qxd:WILEY 9/19/11 10:05 AM Page XI XI PREFACE John Wiley & Sons, Inc. is pleased to present the second edition of Interior Graphic Standards, Student Edition. It is our hope that students of interior design will find in this volume a companion for all aspects of their design education. The student edition serves as a reference for the core classes required by all curriculums, including construction methods and materials, furniture selection, design studio, acoustics, lighting, mechanical, electrical, and other building systems, construction detailing and documentation, and human factors. Although this student edition is an abridgment of the second edition of Interior Graphic Standards, it contains more than half of the original material. Students of interior design are at the beginning of a lifetime of building the skills and acquiring the knowledge and resources required for an inspired design practice. It is our hope that Interior Graphic Standards, Student Edition will serve as both a launching pad and touchstone in these endeavors to all who seek its guidance. The second edition of Interior Graphic Standards Student Edition has been completely updated and reorganized. The content has been expanded to include more information on residential—as well as commercial—interior design. The book has been divided into two sections, followed by an appendix, a glossary, and an index. Design Principles and Process, the first section, addresses issues which students will use across many areas of study. These include environmental and behavioral issues, acoustical principles, accessible design, sustainable design, and design basics. Evidence-based design, building codes, programming, contract documents, and computing technologies are included as design basics. Building Elements, the second section, uses concise text and clear line drawings to detail building structure and shell, interior construction, and equipment and furnishings. Building structure and shell topics include basics of substructure, floor, ceiling and roof construction, stairs and ramps, and exterior walls. Interior construction topics include fire resistive and seismic considerations that affect interiors, interior construction components and finishes, and building services. This section ends with a chapter of interior project types, including commercial, residential, healthcare, retail, hospitality, and educational spaces. Performance spaces, museums, athletic and fitness spaces, animal care facilities, and existing building interiors are also represented here. This chapter is ideal for finding information for specific design projects. The material at the end of the book—the Appendix, Glossary, and Index— makes it easy for students to look up basic information. From front to back, Interior Graphic Standards Student Edition, 2nd Edition is designed with the needs of students and their teachers in mind. There are additional materials on the book’s website, www.wiley.com/go/interiorgraphicstandards2e, including a list of websites by topic for student use, and for teachers, additional extra images and PowerPoint presentations that can be customized for in-class presentations. Corky Binggeli, ASID Editor-in-Chief Arlington, Massachusetts 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 1 SECTI O N 1 DESIGN PRINCIPLES AND PROCESS CHAPTER 1 3 Environmental and Behavioral Issues CHAPTER 2 13 Acoustical Principles CHAPTER 3 18 Accessible Design Basics CHAPTER 4 24 Sustainable Design Basics CHAPTER 5 29 Design Basics 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 2 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 3 ENVIRONMENTAL AND BEHAVIORAL ISSUES 1 H UM AN FACTO R S Human factors information refers to the variables that affect human performance in the built environment, such as human physiology and human psychology. Data accumulated from the fields of engineering, biology, psychology, and anthropology are integrated in this multidisciplinary field. Fit describes a design that uses human factors information to create a stimulating but nonstressful environment for human use. Some areas of fit are physiological, psychological, sensual, and cultural. ANTHROPOMETRICS AND ERGONOMICS The field of anthropometrics provides information about the dimensions and functional capacity of the human body. Static anthropometrics measures the body at rest; dynamic anthropometrics measures the body while it is performing activities defined as “work.” Dimensional variation occurs in anthropometric data because of the large range of diversity in the human population. To utilize anthropometric charts effectively, a designer must identify where a subject user group falls in relationship to these variables. The factors that cause human variations are gender, age, ethnicity, and race. Patterns of growth affected by human culture cause variation in human measure as well. Percentiles that refer to the frequency of occurrence describe dimensional variations on anthropometric charts: that is, the mean percentile (50%), the small extreme percentile (2.5%), and the large extreme percentile (97.5%). 04_9780470889015_ch01.qxd:WILEY 4 9/19/11 10:08 AM Page 4 E N VIRO NM E NTAL AND BEHAVIORAL ISSUES MEASURE AND DEVELOPMENT OF TODDLERS—2.5 TO 4 YEARS 1.1 HUMAN F ACTO R S 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 5 HUMAN FACTORS MEASURE AND DEVELOPMENT OF YOUTHS—7 TO 8 YEARS 1.2 ENVIRONMENTAL AN D BE H AVI O R AL I SSU E S 5 04_9780470889015_ch01.qxd:WILEY 6 9/19/11 10:08 AM Page 6 E N VIRO NM E NTAL AND BEHAVIORAL ISSUES MEASURE OF MAN—FRONT VIEW 1.3 HUMAN F ACTO R S 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 7 HUMAN FACTORS MEASURE OF MAN—SIDE VIEW 1.4 ENVIRONMENTAL AN D BE H AVI O R AL I SSU E S 7 04_9780470889015_ch01.qxd:WILEY 8 9/19/11 10:08 AM Page 8 E N VIRO NM E NTAL AND BEHAVIORAL ISSUES MEASURE OF WOMAN—FRONT VIEW 1.5 HUMAN F ACTO R S 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 9 HUMAN FACTORS MEASURE OF WOMAN—SIDE VIEW 1.6 Contributor: Alvin R. Tilley, Henry Dreyfus Associates, The Measure of Man & Woman: Human Factors in Design, John Wiley & Sons, New York, 2001. ENVIRONMENTAL AN D BE H AVI O R AL I SSU E S 9 04_9780470889015_ch01.qxd:WILEY 10 9/19/11 10:08 AM Page 10 E N VIRO NM E NTAL AND BEHAVIORAL ISSUES Ergonomics is the application of human factors data to design. This term was coined by the U.S. Army when it began to design machines to fit humans, rather than trying to find humans to fit machines. HUMAN F ACTO R S HIERARCHY OF NEEDS 1.7 HUMAN BEHAVIOR Human behavior is motivated by innate attributes such as the five senses and by learned cultural attributes. Each human has a unique innate capacity to gather sensual information. How that information is understood is determined by personal and cultural experience. Proxemics is the study of human behavior as it relates to learned cultural behavior. Human behavior originates in the expression of a person’s genetic code, modified by his or her experience. HIERARCHY OF NEEDS Psychologist Abraham Maslow created a theoretical model that describes human needs and motivations. His hierarchy of needs is presented as a constantly evolving process, such that when a person satisfies one need, another presents itself, and the individual will be driven to satisfy that set of needs. Maslow’s hierarchy of needs is presented as a pyramid depicting the levels of psychological and physical human needs. The two levels at the pyramid’s base—physiological and safety—are required for survival in a hostile environment. Physiological needs include air, food, water, sex, sleep, and other drives that sustain life and health. Safety includes security, order, and stability necessary to protect an individual’s body, family, and property. The three levels at the top of the pyramid—belonging, self-esteem, and self-actualization—are the focus of programming for most interior spaces. Belonging is associated with love and with membership in friendships, family life, and sexual relationships. Selfesteem relates to confidence, achievement, and mutual respect. The final level at the top of the pyramid is self-actualization, which involves fulfilling one’s own highest needs and striving for one’s fullest potential as a human being; it is associated with morality, creativity, problem solving, and other open-minded behaviors. DISTANCE RELATIONSHIPS Some aspects of human behavior related to territoriality are cultural. The space between objects has form, but the space between people is kinetic. The dimension of human territoriality varies in dimension because of cultural forces. • Defensible space occurs when designed form reinforces meaning for the user and where boundary and ownership are visible in public space • Intimate space is where lovers, family, small children, and close friends are allowed to enter • Personal space is a protected area, where strangers are not welcome. • Social space is the range of space in which most public interactions occur. Speech and expression are clear and communications are efficient and accurate. • Public distance is the range of space where it is not considered rude to ignore someone, and interaction is not allowed. DISTANCE RELATIONSHIPS AMONG PEOPLE 1.8 04_9780470889015_ch01.qxd:WILEY 9/19/11 10:08 AM Page 11 WAYF INDING ENVIRONMENTAL AND BE H AVI O R AL I SSU E S W AY FIND ING Wayfinding refers to the way people orient themselves in a given environment and find their destination. The ability to orient oneself is based on many pieces of information, including visual clues, memories, and knowledge of a place, along with the ability to reason. Environmental psychology terms the ability to acquire, code, store, recall, and decode information about the physical environment cognitive mapping. Successful wayfinding is the ability to naturally orient oneself in the environment and to easily locate a destination without experiencing stress. MAPPING Three components for the analysis of environmental imaging include: • Identity, or objects in background • Structure, or objects in relationship to each other • Meaning, or personal, societal, or figurative belief A highly imageable space has components that relate in a wellstructured manner. The way a space is mapped for an individual varies, depending on the person. Certain images and visual clues are perceived similarly by groups of people who share similar backgrounds, activities, or routines, and recurrent features in their environment. For example, a group of schoolchildren may be of a similar age, share the learning and play activities of a school, and be aware of the physical features of the school building. MAPPING ELEMENTS Lynch’s research resulted in the identification of five categories of elements that people use to map an environment: • • • • • Paths: Channels of movement Edges: Boundaries that break, contain, or run parallel to forms Districts: Areas of recognizable identity Nodes: Places of intense activity Landmarks: Points of reference that are visually distinguishable COGNITIVE MAPS Cognitive maps are psychological impressions or representations of an individual’s ability to understand space and the organizing elements by which they orient themselves. Cognitive maps usually combine several of the mapping elements. Three-dimensional characteristics of a space, material choices, colors, and lighting can all impact the formation of edges, districts, or nodes. Where the boundaries of the districts meet, an edge may be formed, providing a sense of having exited one area and entered another. A node may occur at an intersection of activities or along paths where activity is concentrated. Landmarks may be used by the designer to mark entrances or points of interest. WAYFINDING AND AGE The process of learning involves an increase in perception of detail as a person develops. Adults navigate wide-reaching, complex environments on a daily basis, whereas children’s environments are more limited in range and tend to be perceived on the basis of reference points. The designer of environments for small children should be aware that children are naturally oriented in relation to their own positions. Children see the world always in relation to themselves. For example, an especially enjoyable piece of equipment at the playground and its relationship to the toilet facility a child uses while at the playground may be the elements by which he or she organizes and understands that environment. A child’s cognitive map will likely include detailed aspects of a space with which he or she is directly involved. MAPPING ELEMENTS 1.9 11 04_9780470889015_ch01.qxd:WILEY 12 9/19/11 10:08 AM Page 12 E N VIRO NM E NTAL AND BEHAVIORAL ISSUES The adolescent child’s orientation system may be based on a local hangout, the path of travel between home and school, local landmarks within the community, and similar points of reference. As adults, people tend to rely on maps, diagrams, and more highly abstract information for orientation and finding their way within a new area. An adult who is visiting an unfamiliar city may use a city map to reach a destination. SIGNAGE AND WAYFINDING CLUES Signage is an important part of directing people through a space. Building signage can include building identification, building layout illustration, directional signs, and place signs. Contributors: Bradford Perkins (Stephen Kliment, Ed.), Building Type Basics for Elementary and Secondary Schools, John Wiley & Sons, Inc., New York, 2001, pp. 193–200 Kevin Lynch, The Image of the City, MIT Press, Cambridge, 1960 Gary T. Moore, “The Development of Environmental Knowing: An Overview of an Interactional-Constructivist Theory and Some Data on Within-Individual Development Variations” in Psychology and the Built Environment, David Carter and Terrence Lee, Eds. Architectural Press, London, 1976 WAYF INDIN G Signs should be designed and placed consistently throughout the facility. The overuse of signage and cluttered signage becomes ineffective, and should be avoided. Signs should be placed strategically at decision-making areas. WAYFINDING CLUES In addition to signage, visual clues can be utilized to help orient the user. Architectural elements like lobbies, stairs, elevators, and areas of special use can create a framework into which users can place themselves. The following interior treatments typically used for aesthetic effect can also assist the designer in creating a highly understandable environment: • • • • • Change of wall color, type, or texture Change in flooring Use of lighting to highlight or minimize areas Change of ceiling treatments Furniture arrangement or type. The extent of wayfinding clues incorporated in the environment should vary from public to private spaces. Public areas require more information to be presented to aid visitors in locating their destinations. As the spaces become more private, fewer clues will be needed because of the occupant’s knowledge of the environment. 05_9780470889015_ch02.qxd:WILEY 9/19/11 10:11 AM Page 13 ACOUSTICAL PRINCIPLES 2 BASICS OF ACOUSTICAL DESIGN SOUND SOUND AND FREQUENCY 2.3 Sound is energy produced by a vibrating object or surface and transmitted as a wave through an elastic medium. Such a medium may be air (airborne sound) or any solid common building material, such as steel, concrete, wood, piping, gypsum board, and so on (structure-borne sound). A sound wave has amplitude and frequency. The amplitude of sound waves is measured in decibels (dB). The decibel scale is a logarithmic scale based on the logarithm of the ratio of a sound pressure to a reference sound pressure (the threshold of audibility). The values of a logarithmic scale, such as the decibel levels of two noise sources, cannot be added directly. Instead, use the simplified method described in Table 2.1. For example, 90 dB + 20 dB = 90 dB; 60 dB + 60 dB = 63 dB. AMPLITUDE (DECIBELS) 2.1 in dBA, or A-weighted decibels. This is the most universally accepted single-number rating for human response to sound. Difference between sound levels (in dB) 0 to 1 2 to 3 4 to 9 10 Add this number to higher sound level 2 0 3 1 SUBJECTIVE REACTIONS TO CHANGE IN SOUND LEVEL 2.2 CHANGE IN SOUND LEVEL, dB 1 to 2 CHANGE IN APPARENT LOUDNESS Imperceptible 3 Barely perceptible 5 to 6 Clearly noticeable 10 Significant change—twice as loud (or half as loud) 20 Dramatic change—four times as loud (or a quarter as loud) FREQUENCY The frequency of sound waves is measured in hertz (Hz; also known as cycles per second) and grouped into octaves; an octave band is labeled by its geometric center frequency. An octave band covers the range from one frequency (Hz) to twice that frequency (f to 2f). The range of human hearing covers the frequencies from 20 to 16,000 Hz. Human hearing is most acute in the 1,000- to 4,000-Hz octave bands. The human ear discriminates against low frequencies in a manner matched by the A-weighting filter of a sound-level meter, measured SOUND ABSORPTION PROPERTIES OF MATERIALS All materials and surfaces absorb some sound. The percentage of incident sound energy that is absorbed by a material, divided by 100, equals the coefficient of absorption, which ranges from 0 to 0.99. The coefficient varies as a function of frequency, measured in hertz. The sound absorption coefficient for a given material may vary depending on the thickness of the material, how it is supported or mounted, the depth of the air space behind the material, and the facing in front of the material. In general, thicker, porous materials absorb more sound. The air space behind a material will increase the absorption efficiency, especially at low frequencies. Thin facings degrade high-frequency absorption. SOUND ENERGY ABSORPTION MECHANISMS There are three mechanisms by which sound energy is absorbed or dissipated as it strikes a surface. In all cases, sound energy is converted to heat, although not enough heat to be felt. Porous absorption entails the use of soft, porous, fuzzy materials such as glass fiber, mineral wool, and carpet. The pressure fluctuations of a sound wave in air cause the fibers of such materials to move, and the friction of the fibers dissipates the sound energy. Panel absorption involves installation of thin lightweight panels such as gypsum board, glass, and plywood. Sound waves cause these panels to vibrate. Sound absorption for a panel is greatest at its natural or resonant frequency. Cavity absorption entails the movement of air pressure fluctuations across the narrow neck of an enclosed air cavity, such as the space behind a perforated panel or a slotted concrete masonry unit, also called a Helmholtz resonator. Friction of the resonating air molecules against the wall of the neck converts sound energy to heat. If there is also insulation within the cavity, additional energy is extracted via the porous absorption mechanism. ACOUSTICAL MEASUREMENT TERMS • Apparent Sound Transmission Class (ASTC): Field measurement that covers all sound transfer paths between spaces. • Articulation index (AI): Measures how materials affect speech intelligibility in offices. • Average room absorption coefficient (average coefficient of absorption): Total room absorption divided by total room surface area. • Coefficient of absorption (absorption coefficient): Percent of sound energy absorbed by a material. • Decibel (dB): Measures sound pressure (perceived as relative loudness). • Hertz (Hz): Measures frequency (perceived as high or low pitch). • Impact Isolation Class (IIC): Measures impact sound transmissions through floor assemblies. • Noise criteria (NC): Standard spectrum curves used to describe a given measured noise. • Noise reduction (NR): Measures actual difference in sound pressure levels at any two points along a sound path. • Sabin: Unit of sound absorption. • Sound absorption average (SAA): Average of sound absorption coefficients. 05_9780470889015_ch02.qxd:WILEY 14 9/19/11 10:11 AM Page 14 ACO U ST ICAL PR INCI PLES ROOM ACOUSTICS • Sound absorption coefficient: Measures absorptive property of a material in a specified frequency band. • Sound transmission class (STC): Provides an estimate of the performance of a partition in certain common sound insulation situations. • Sound transmission loss (TL): Measures attenuation of airborne sound through a construction assembly. • Speech absorption coefficient (SAC): Tool for evaluating the effectiveness of ceiling materials for sound absorption. SOUND-ABSORBING COEFFICIENTS FOR VARIOUS MATERIALS 2.4 MEASURING SOUND ABSORPTION MATERIAL 125 Hz 250 Hz 500 Hz 1,000 Hz 2,000 Hz 40,000 Hz Marble 0.01 0.01 0.01 0.01 0.02 0.02 NRC 0.00 Gypsum board, 1/2⬙ (13 mm) 0.29 0.10 0.05 0.04 0.07 0.09 0.05 Wood, 1⬙ (25 mm) thick, with air space behind 0.19 0.14 0.09 0.06 0.06 0.05 0.10 Heavy carpet on concrete 0.02 0.06 0.14 0.37 0.60 0.65 0.30 Acoustical tile, surface mounted 0.34 0.28 0.45 0.66 0.74 0.77 0.55 One measure of the quality of sound in a room is the average coefficient of absorption for all surfaces combined. As determined by using the average coefficient of absorption, the quality of sound in a room can be evaluated as 0.1, 0.2, or 0.3. A room with an average coefficient of 0.1 is rather acoustically live, loud, and uncomfortably noisy; one with an average coefficient of 0.2 is comfortable, with well-controlled noise; and one with 0.3 is rather acoustically dead, suitable for spaces in which the emphasis will be on amplified sound, electronic playback, or a live microphone for teleconferencing. Acoustical tile, suspended 0.43 0.38 0.53 0.77 0.87 0.77 0.65 Acoustical tile, painted (est.) 0.35 0.35 0.45 0.50 0.50 0.45 0.45 Audience area: empty, hard seats 0.15 0.19 0.22 0.39 0.38 0.30 0.30 Audience area: occupied, upholstered seats 0.39 0.57 0.80 0.94 0.92 0.87 0.80 Glass fiber, 1⬙ (25 mm) 0.04 0.21 0.73 0.99 0.99 0.90 0.75 Glass fiber, 4⬙ (100 mm) 0.77 0.99 0.99 0.99 0.99 0.95 1.00 Thin fabric, stretched tight to wall 0.03 0.04 0.11 0.17 0.24 0.35 0.15 The sound absorption average (SAA) is a single-number measure of sound absorption. The SAA is the average of sound absorption coefficients of a material from 200 to 2,500 Hz inclusive. Thick fabric, bunched 4⬙ (100 mm) from wall 0.14 0.35 0.55 0.72 0.70 0.65 0.60 ROO M ACO U ST ICS The sabin is defined as a unit of sound absorption. One square meter of 100% absorbing material has a value of one metric sabin. The unit is named in honor of Wallace Clement Sabine, considered the father of acoustical design. The total sabins in a room can be determined by adding together the sabins of all the surfaces, which vary as a function of frequency. Because most materials absorb more high-frequency sound waves than low-frequency ones, it is typical to find more sabins in a room at high frequencies than at low frequencies. Shorter reverberation times greatly enhance speech intelligibility and are imperative in listening environments for people with hearing impairments and for rooms with live microphones for teleconferencing. Longer reverberation times add richness to concert and liturgical music. USE OF SOUND-ABSORPTIVE MATERIALS In general, sound energy that is not absorbed will be reflected; thus, surfaces with low coefficients of absorption can be used to encourage sound reflection when appropriate. Sound-absorptive materials (such as acoustical tile, glass fiber, wall panels, carpet, curtains, etc.) can be added to a room in order to control or reduce noise levels or shorten reverberation time. Noise PROPERTIES OF SOUND GUIDELINES FOR USE OF SOUND ABSORPTION 2.5 Distance and time are two defining properties of sound. Outdoors, sound drops off 6 dB each time the distance from a source is doubled (inverse square law). Indoors, the reflecting sound energy in a room reaches a constant level as a function of the sound-absorbing units (sabins) in the room. Outdoors, sound ceases when the source stops. Indoors, sound energy lingers; this decay is called reverberation. The reverberation time (RT) is defined as the length of time in seconds that it takes for sound to decay by 60 dB. Reverberation time is directly proportional to the volume of a space and inversely proportional to the units of absorption (sabins) in it. ROOM TYPE control is especially helpful when the noise sources are distributed around a room, as in a gymnasium, classroom, or cafeteria. While sound-absorptive materials can be added to any surface in a room, the greatest area available for coverage is usually the ceiling. Because many soft, porous materials are fragile, they should not be located on surfaces that are susceptible to abuse. For these reasons, sound-absorptive materials are often installed on ceilings. However, limiting absorption to one surface or to two parallel surfaces may not effect as great a change as calculated, because an assumption of the reverberation and noise reduction formulas is that the absorption is rather evenly distributed among the surfaces of the space. TREATMENT Classrooms, corridors and lobbies, patient rooms, laboratories, shops, factories, libraries, private and open-plan offices, restaurants Ceiling or equivalent area; add additional wall treatment if room is quite high Boardrooms, teleconferencing rooms, gymnasiums, arenas, recreational spaces, meeting and conference rooms Ceiling or equivalent; add wall treatments for further noise reduction and reverberation control and to eliminate flutter or echo Auditoriums, churches, acoustically sensitive spaces Special considerations and complex applications 05_9780470889015_ch02.qxd:WILEY 9/19/11 10:11 AM Page 15 SOUND TRANSMISSION ACO U ST I CAL PR I N CI PLE S S O U ND T R ANSM ISSION The property of a material or construction system that blocks the transfer of sound energy from one side to another is sound transmission loss (TL), which is measured in decibels. Specifically, TL is the attenuation of airborne sound transmission through a construction during laboratory testing. Transmission loss values range from 0 to 70 or higher. A high TL value indicates a better capability to block sound; that is, more sound energy is lost (transformed into heat energy) as the sound wave travels through the material. Sound transmission class (STC) is a single-number rating system designed to combine TL values from many frequencies. STC values for site-built construction range from 10 (practically no isolation; e.g., an open doorway) to 65 or 70 (such high performance is only achieved with special construction techniques). Average construction might provide noise reduction in the range of STC 30 to 60. SOUND ISOLATION IMPACT NOISE REDUCTION One of the most common goals in the design of sound isolation construction is achievement of acoustical privacy from a neighbor. This privacy is a function of whether the signal from the neighbor is audible and intelligible above the ordinary background noise level in the environment. Noise reduction is measured as a field performance, where it is evaluated and given an STC value. The privacy index is equal to noise reduction plus background noise that masks speech sounds. Often the greatest annoyance caused by footfall noise is the lowfrequency sound energy it generates, which is beyond the frequency range of standardized tests. Sometimes this sound energy is near or at the resonant frequency of the building structure. Whenever possible, stifle unwanted sounds by using carpet with padding on floors in residential buildings, and resilient, suspended ceilings with cavity insulation. Normal privacy, in which you are aware of a neighbor’s activity but not overly distracted by it, can usually be achieved with a privacy index of 68 or higher. Confidential privacy, in which you are unaware of the neighbor, usually requires a privacy index of 75 or higher. It is very difficult to measure the STC performance of a single wall or door in the field because of the number of flanking paths and nonstandard conditions. Field performance is measured with Apparent Sound Transmission Class (ASTC) ratings, which cover effects from all sound transfer paths between rooms. The level of continuous background noise, such as that provided by the heating, ventilating, and air conditioning (HVAC) system or by electronic masking, has a significant impact on the quality of construction selected and must be coordinated with the other design parameters. TRANSMISSION LOSS SOUND ISOLATION CRITERIA 2.6 Design of construction and materials for high transmission loss builds on three principles: mass, separation, and absorption. Mass: Lightweight materials do not block sound. Sound transmission through walls, floors, and ceilings varies with the frequency of sound, the weight (or mass) and stiffness of the construction, and the cavity absorption. BACKGROUND LEVEL IN SOURCE ROOM: OCCUPANCY School buildings Separation: Improved TL performance without an undue increase in mass can be achieved by separation of materials. A true double wall with separate unconnected elements performs better than the mass law predicts for a single wall of the same weight. Resilient attachment of surface skins to studs or structural surfaces provides a similar benefit, as do separate wythes. Absorption: Use of soft, resilient, absorptive materials in the cavity between wythes, particularly for lightweight staggered or double-stud construction, increases transmission loss significantly. If two layers of dense material are separated by an air space (rather than being continuous), they create two independent walls. The improvement in transmission loss depends on the size of the air space and the frequency of the sound. Executive areas, doctors’ suites, confidential privacy Normal offices, normal privacy requirements, group meeting rooms NOISE REDUCTION Noise reduction (NR) depends on the properties of a room and is the actual difference in sound pressure level between two spaces. It is the amount of sound blocked by all intervening sound paths between rooms, including the common wall but also the floor, ceiling, outside path, doors, and other flanking paths. Noise reduction also depends on the relative size of a room. If the noise source is in a small room next to a large receiving room (e.g., an office next to a gymnasium), the noise reduction will be greater than the TL performance of the wall alone because the sound radiating from the common wall between office and gym will be dissipated in such a large space. On the other hand, if the noise source is in a large room next to a small one (as from a gym to an office next door), the noise reduction will be far less than the TL of the wall alone because the common wall, which radiates sound, is such a large part of the surface of the smaller room. Slamming doors or cabinet drawers are other sources of impact noise. If possible, bureaus should not be placed directly against a wall. Door closers or stops can be added to cushion the impact of energy from a door so it is not imparted directly into the structure. Commonsense arrangements can help minimize problems in multifamily dwellings. For example, kitchen cabinets should not be placed on the other side of a common wall from a neighbor’s bedroom. SOURCE ROOM Classrooms ADJACENT AREA Adjacent classrooms QUIET NORMAL STC 42 STC 40 Corridor or public areas STC 40 STC 38 Kitchen and dining areas STC 50 STC 47 Shops STC 50 STC 47 Recreation areas STC 45 STC 42 Music rooms STC 55 STC 50 Mechanical equipment rooms STC 50 STC 45 Toilet areas STC 45 STC 42 Music practice rooms Adjacent practice rooms STC 55 STC 50 Corridor and public areas STC 45 STC 42 Office Adjacent offices STC 50 STC 45 STC 45 Office Conference rooms General office areas STC 48 Corridor or lobby STC 45 STC 42 Washrooms and toilet areas STC 50 STC 47 Adjacent offices STC 40 STC 38 Corridor, lobby, exterior STC 40 STC 38 Washrooms, kitchen, dining STC 42 STC 40 Other conference rooms STC 45 STC 42 Adjacent offices STC 45 STC 42 Corridor or lobby STC 42 STC 40 Exterior STC 40 STC 38 STC 42 Kitchen and dining areas STC 45 Large offices, computer work areas, banking floors, etc. Large general office areas Corridors, lobby, exterior STC 48 STC 35 Data processing areas STC 40 STC 38 Kitchen and dining areas STC 40 STC 38 Motels and urban hotels, hospitals, dormitories Bedrooms Adjacent bedrooms STC 52 STC 50 Adjacent single bathroom STC 50 STC 45 Adjacent living rooms STC 45 STC 42 Dining areas STC 45 STC 42 Corridor, lobby, or public spaces STC 45 STC 42 Source: Adapted from Benjamin Stein, John S. Reynolds, Walter T. Grondzik, and Alison G. Kwok, Mechanical and Electrical Equipment for Buildings, 10th ed. (John Wiley & Sons, New York, 2006). 15 05_9780470889015_ch02.qxd:WILEY 16 9/19/11 10:11 AM Page 16 ACO U ST ICAL PR INCI PLES SOUND TRANSMISSION TYPICAL HIGH SOUND ISOLATION CONSTRUCTION 2.7 ACOUSTICAL PARTITIONS MODIFIED FULL-HEIGHT PARTITION 2.9 The reduction of airborne sound transmission, such as normal conversation and other office noise, is identified by STC ratings. The STC does not identify reductions of impact or vibration noise, which are classified by the IIC ratings. RECOMMENDED STC VALUES 2.8 RECEIVING ROOM Offices requiring privacy (doctors, executives) Other office areas Conference and training rooms Hotel bedrooms Classrooms (K to 12) All areas NOTE 2.9 The ceiling is installed prior to installation of the partition. This detail can be used when improved acoustical qualities are desired and economy of installation is required. It is not as stable as a full-height partition with studs continuous to the structure above. STC rating of 40 to 44. SOURCE ROOM STC Lobby or corridor 50 General office 45 Adjacent office 50 Toilet room 55 Lobby or corridor 45 Kitchen or dining room 45 Other conference room 50 Adjacent office 50 General office 50 Lobby or corridor 50 Toilet room 55 Adjacent bedroom, living room, or bathroom 55 Lobby or corridor 55 Adjacent classroom 45 Laboratory 50 Lobby or corridor 50 Kitchen or dining room 50 Vocational shop 55 Music room 55+ Toilet room 50 Mechanical room 60 05_9780470889015_ch02.qxd:WILEY 9/19/11 10:11 AM Page 17 SOUND TRANSMISSION DOUBLE-LAYER GYPSUM BOARD PARTITION 2.10 SOUND-ISOLATED ASSEMBLIES 2.12 SOUND CONTROL CEILING-HEIGHT PARTITION WITH SOUND ATTENUATION 2.11 The reduction of airborne sound passing through a wall, floor, or ceiling is identified by the sound transmission class (STC). Acoustics affect diverse aspects of daily life, from the productivity of office workers and performance quality in theaters and auditoriums to the market value of apartments, condominiums, and single-family homes. In addition, industries such as healthcare and financial must comply with stringent federal privacy regulations requiring service providers to make reasonable efforts to assure speech privacy in patient and customer consultation areas. Depending on the purpose of the room, primary acoustical requirements could include sound control between spaces, within a space, or listening efficiency. Testing, conducted under controlled laboratory conditions, according to ASTM procedures, provides a measurement of maximum performance potential. The actual ability of partitions and assemblies to control sound in real-life applications, however, depends on their design and the methods used to install them. Partition STC ratings are dependent on the partition: • • • • Mass Resiliency (or isolation) Dampening Sound absorption Multilayer partitions have more mass than single-layer partitions. Wood studs are less resilient than steel studs and transmit more sound. Sound attenuation insulation provides good sound dampening and absorption. Acoustical partitions require sealant at the perimeter (typically top and bottom) edges of the partition assembly, as well as at openings in the gypsum panels such as electrical boxes, mechanical ducts, and other penetrations. NOTES 2.10 This figure shows a nonrated partition that can achieve a two-hour rating with Type X gypsum board. This design offers additional security due to a double layer of gypsum board. The resilient channel provides higher-performance sound control. Acoustical sealant is required for an STC rating of 55 to 60. 2.11 This figure shows a nonrated partition commonly used in commercial and high-quality residential construction. The ceiling is installed prior to installation of the partition. Normal conversation is not audible, but loud sounds may be transmitted through the partition. STC rating of 40 to 44. 2.13 Arrows indicate flanking paths Contributors: Jim Johnson, Wrightson, Johnson, Haddon & Williams, Inc., Dallas, Texas. Doug Sturz and Carl Rosenberg, AIA, Acentech, Inc., Cambridge, Massachusetts. ACO U ST I CAL PR I N CI PLE S ACOUSTICAL CONSTRUCTION 2.13 17 06_9780470889015_ch03.qxd:WILEY 9/19/11 10:14 AM 3 Page 18 ACCESSIBLE DESIGN BASICS ACCESSIBILITY DEFINITIONS Accessible is a design term that describes elements of the physical environment that can be used by people with disabilities. Originally, the term described facilities that could be accessed by wheelchair users, but it has evolved to include designs for a wider group of people with more diverse functional requirements. From a designer’s perspective, there is a difference between appropriate accessible design for public facilities and the best approach for private, custom accessible projects. Public accessibility standards establish general design specifications that broadly meet the targeted population’s needs. By contrast, custom accessible design should address the specific needs of an individual user. ACCESSIBILITY STANDARDS TERMS The following terms are used in accessibility standards; definitions may vary among standards: • Alteration: Any change that affects usability. This includes remodeling, renovation, rearrangements in structural parts, and changes or rearrangement of walls and full-height partitions. • Commercial facilities: This category includes nonresidential facilities whose operations affect commerce. • Continuing obligation: Barriers must be removed whenever it becomes readily achievable to do so. • Multifamily housing: As defined by the ABA, FHAA, ADA, and Section 504 of the Rehabilitation Act of 1973, multifamily housing is a “building with four or more dwelling units.” Further, they state that “dwelling units within a single structure that are separated by fire walls do not constitute separate buildings.” • Path of travel: This is a continuous route connecting an altered area to the entrance and point of arrival. It can include sidewalks, lobbies, corridors, and elevators, as well as telephones, restrooms, and drinking fountains serving the altered area. • Place of public accommodation: This set of facilities has retroactive requirements. There are 12 categories that include the following: • Places of lodging (e.g., inns, hotels, motels, except for owneroccupied establishments renting fewer than six rooms) • Establishments serving food or drink (e.g., restaurants and bars) • Places of exhibition or entertainment (e.g., motion picture houses, theaters, concert halls, stadiums) • Places of public gathering (e.g., auditoriums, convention centers, lecture halls) • Sales or rental establishments (e.g., bakeries, grocery stores, hardware stores, shopping centers) • Service establishments (e.g., shops, professional offices, hospitals) • Public transportation terminals, depots, or stations (not including facilities relating to air transportation) • Places of public display or collection (e.g., museums, libraries, galleries) • Places of recreation (e.g, parks, zoos) • Places of education (e.g., nursery schools; elementary, secondary, undergraduate, or postgraduate schools) • Social service center establishments (e.g., day care centers, senior citizen centers, homeless shelters, food banks, adoption agencies) • Places of exercise or recreation (e.g., gymnasiums, health spas, bowling alleys, golf courses) • Primary function: Any area in which a major activity takes place. It does not include mechanical rooms, boiler rooms, supply storage rooms, employee lounges or locker rooms, janitorial closets, entrances, corridors, or restrooms. • Private club: To qualify, these organizations must meet the following criteria: • Members exercise a high degree of control over club operations; the membership selection process is highly selective; substantial membership fees are charged; the entity is operated on a nonprofit basis; the club was not founded specifically to avoid compliance with federal civil rights laws. • Readily achievable: According to the laws, this means “easily accomplishable and able to be carried out without much difficulty or expense.” The Department of Justice lists examples of what is readily achievable, including: • Installing ramps; making curb cuts in sidewalks and entrances • Repositioning shelves; rearranging tables, chairs, vending machines, display racks, and other furniture; repositioning telephones • Adding raised markings on elevator control buttons • Installing flashing alarm lights • Widening doors; installing offset hinges to widen doorways; installing accessible door hardware • Eliminating a turnstile or providing an alternative, accessible path • Installing grab bars in toilet stalls; rearranging toilet partitions to increase maneuvering space; insulating lavatory pipes under sinks to prevent burns; installing a raised toilet seat; installing a full-length bathroom mirror; repositioning the paper towel dispenser in a bathroom • Installing an accessible paper cup dispenser at an existing inaccessible water fountain • Removing high-pile, low-density carpeting ADA AND FHAA DESIGN REQUIREMENTS The Americans with Disabilities Act (ADA) and the Fair Housing Amendments Act (FHAA) are the two broad federal civil rights laws that address accessible design and construction of both public and private facilities. The FHAA covers multifamily housing. The ADA is applied to a wide range of public accommodations offered by private entities (Title III) and municipal facilities (Title II). Other federal laws, such as the Rehabilitation Act of 1973, may also apply to some projects. Contributors: Kim A. Beasley, AIA, and Thomas D. Davies Jr., AIA, Paralyzed Veterans of America Architecture, Washington, DC. The ADA includes design requirements for new facility construction and for additions to, and alterations of, existing facilities that are owned, leased, or operated by both private entities and local governments. However, design standards and management responsibilities differ between the two owner groups. Owners and operators of existing private facilities that serve the public have ADA construction responsibilities under what is called barrier removal. Local governments also have the responsibility of making all their new and existing programs accessible. Meeting this ADA responsibility for municipal programs sometimes may require new construction or physical modifications to existing facilities. The ADA also prescribes employer responsibilities for changing their policies or modifying their facilities to accommodate employees with disabilities (Title I). Several ADA concepts determine design requirements, such as path of travel components for renovation projects and the elevator 06_9780470889015_ch03.qxd:WILEY 9/19/11 10:14 AM Page 19 ADA AND FHAA DESIGN REQUIREMENTS exception for small multistory buildings. It is imperative that designers familiarize themselves with all aspects of the law, as well as with the design standards. The FHAA addresses new multifamily housing constructed by either private entities or local governments. Generally, it covers apartments, dormitories, and other lodgings included in projects with four or more total dwelling units that are built for sale or lease. Existing housing structures and any remodeling, conversion, or reuse projects are not covered by the FHAA. The FHAA guidelines allow the exclusion of certain dwelling units because of site considerations, such as steep topography and floodplains. The guidelines include site practicality tests for analyzing site constraints. ACCESSI BLE D E SI G N BASI CS Knee and toe clearance that is included as part of a T-shaped turning space should be provided only at the base of the T or on one arm of the T. In some configurations, the obstruction of part of the T-shape may make it impossible for a wheelchair user to maneuver to the desired location. Additional space can be provided beneath the table, desk, or other element, but that space is not considered knee and toe clearance. Minimum clearances are required at specific accessible elements. Knee and toe clearance must always be at least 30 in. (762 mm) wide. Toe clearance does not have to extend to the wall. KNEE AND TOE CLEARANCES Knee and toe clearance can be included as part of the wheelchair turning space and clear floor space at accessible elements. However, the extent and location of knee and toe clearance can affect the usability of the space. WHEELCHAIR MANEUVERING CLEARANCES 3.1 SAMPLE MANEUVERING CLEARANCES—DRINKING FOUNTAIN 3.2 WHEELCHAIR TURNING SPACE 3.3 19 06_9780470889015_ch03.qxd:WILEY 20 9/19/11 10:14 AM Page 20 AC CE SSIB L E D E SIG N BASICS KNEE AND TOE CLEARANCE 3.4 ADA AND F HAA DESIGN RE Q U I R E ME N T S REACH LIMITS REACH RANGES 3.5 CHILDREN’S REACH RANGES FROM A WHEELCHAIR 3.6 FORWARD OR SIDE REACH Contributor: Mark J. Mazz, AIA, PA, Hyattsville, Maryland. AGES 3 AND 4 AGES 5 TO 8 AGES 9 TO 12 Maximum 36⬙ (914 mm) 40⬙ (1,016 mm) 44⬙ (1,118 mm) Minimum 20⬙ (508 mm) 18⬙ (457 mm) 16⬙ (406 mm) 06_9780470889015_ch03.qxd:WILEY 9/19/11 10:14 AM Page 21 ACCESSIBLITY PROTRUDING OBJECTS Wall sconces, fire alarm appliances, environmental controls, door hardware, signs, and suspended lighting fixtures are examples of protruding objects. Some standards specify the extent to which doorstops and door closers may protrude into the 80 in. (2,032 mm) vertical clearance, generally allowing a 2 in. (51 mm) maximum projection. Protruding objects are not permitted to reduce the required width of an accessible route below 36 in. (914 mm), with one exception: A 32-in. (813-mm) width is permitted for a 24-in. (610-mm) length. DIMENSIONS OF PROTRUDING OBJECTS 3.7 FREESTANDING PROTRUDING OBJECTS 3.8 OVERHEAD-HAZARD PROTECTION 3.9 Contributors: Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, PA, Hyattsville, Maryland. ACCESSI BLE D E SI G N BASI CS 21 06_9780470889015_ch03.qxd:WILEY 22 9/19/11 10:14 AM Page 22 AC CE SSIB L E D E SIG N BASICS ACCESSIBLE ROUTES ACCESSIBLE RO UTES Accessible routes are generally required as follows: • Multilevel buildings and facilities: Required between all levels, including mezzanines, in multistory buildings, unless exempted. • ADA elevator exception: Buildings with only two floors are exempt from providing an accessible route to the upper or lower level. Buildings with less than 3,000 sq ft (279 sq m) per floor, regardless of height, are exempt from providing an accessible route to upper or lower floor levels. Neither exception applies to shopping centers, offices of professional healthcare providers, public transportation terminals, or state and local government facilities. • Building code elevator exception: Model building codes generally exempt a maximum aggregate area of 3,000 sq ft (279 sq m), regardless of the number of levels. Similar to the ADA restrictions, this exception cannot be used in offices of healthcare providers, passenger transportation facilities, or mercantile occupancies with multiple tenants. Consult the applicable local code. • FHAG elevator requirements: Required for buildings containing dwelling units, and not public or common-use spaces. FHAG does not require accessible routes to all levels. Instead, the existence or lack of an elevator determines the extent of units covered. When elevators are provided, they generally must serve all floors; an exception is provided for elevators serving only as a means of access from a garage to a single floor. When elevators are not provided, only the “ground floor” units are subject to the FHAG requirements. In mixed-use construction, an accessible route is required to the first level containing dwelling units, regardless of its location. Consult FHAG for specific requirements. • Levels not containing accessible elements or spaces: For facilities in which only a percentage of the spaces provided are required to be accessible (assembly, residential, institutional, and storage), codes do not require an accessible route to serve levels not containing required accessible spaces. Separate requirements for dispersion of accessible elements and spaces may still require multiple accessible levels. Consult the applicable local code. • Accessible spaces and elements: To all spaces and elements that are required to be accessible. • Toilet rooms and bathrooms: ADA generally requires that all toilet and bathing rooms be accessible. This does not trigger a requirement for accessible routes if the floor level is not otherwise required to have an accessible route. • Alterations: ADA and building codes generally do not require that altered elements trigger a requirement for accessible routes to the elements, unless covered under specific “primary function” requirements. Consult ADA and the applicable local code. COMPONENTS OF ACCESSIBLE ROUTES Accessible routes are permitted to include the following elements: • • • • • Walking surfaces with a slope of less than 1:20 Curb ramps Ramps Elevators Platform (wheelchair) lifts The use of lifts in new construction is limited to locations where they are specifically permitted by the applicable regulations. Lifts are generally permitted to be used as part of an accessible route in alterations. Each component has specific technical criteria that must be applied for use as part of an accessible route. Consult the applicable code or regulation. LOCATION OF ACCESSIBLE ROUTES FLOOR AND GROUND SURFACES Accessible routes must be located as follows: Changes in level greater than 1/2 in. (13 mm) must be ramped. Some standards prohibit changes in level in clear floor space, maneuvering clearances, wheelchair turning space, and access aisles. • Interior routes: Where an accessible route is required between floor levels, and the general circulation path between levels is an interior route, the accessible route must also be an interior route. • Relation to circulation paths: Accessible routes should “coincide with, or be located in the same area as, a general circulation path.” Avoid making the accessible route a “second class” means of circulation. Consult the applicable regulations for additional specific requirements regarding location of accessible routes. • Where the accessible route departs from the general circulation path, and is not easily identified, directional signs should be provided as necessary to indicate the accessible route. CLEAR WIDTH OF AN ACCESSIBLE ROUTE 3.10 All surfaces must be firm, stable, and slip resistant. Other openings, such as in wood decking or ornamental gratings, must be designed so that a 1/2 in. (13 mm) diameter sphere cannot pass through the opening. The potential for wood shrinkage should be considered. 06_9780470889015_ch03.qxd:WILEY 9/19/11 10:14 AM Page 23 ACCESSIBLE ROUTES CHANGES IN LEVEL 3.11 FLOOR AND GROUND SURFACES 3.12 NOTE 3.13 Dimensions shown apply when X is less than 48 in. (1,219 mm). Contributors: Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, PA, Hyattsville, Maryland. TURNS 3.13 ACCESSI BLE D E SI G N BASI CS 23 07_9780470889015_ch04.qxd:WILEY 9/19/11 10:17 AM 4 Page 24 SUSTAINABLE DESIGN BASICS S U STA INA B L E D E SIGN PRINCIPLES We live on a finite planet, and as our population and rate of development are growing across the globe, so is the rate at which we are using the planet’s limited resources to accommodate that growth. There are also direct and indirect consequences of this growth on climate change, and we have only in recent years begun to understand the significance of this on the way we live and the way we design, construct, and operate buildings and their interiors. DEPLETION OF NATURAL RESOURCES Three areas of concern regarding the depletion of limited natural resources are energy, water, and materials. Energy: The majority of the energy produced in the world today is derived from limited fossil fuels. As these resources become INTEGRATED INTERIORS 4.1 scarcer, the price of these fuels rises, thus creating a greater incentive to first conserve energy and then move toward renewable energy sources such as wind, solar, and geothermal. Water: We are depleting our freshwater reserves faster than they are being replenished. It takes a huge amount of energy to purify and pump water from its source to the point of use. Therefore, in recent years, there has been greater focus on water conservation and water treatment and reuse technologies, especially in arid climates. Materials: We are extracting and harvesting our limited natural resources such as wood, stone, and minerals at a rate that cannot be sustained. The full impact of materials extraction and harvesting is not even known. We are destroying ecosystems, reducing the amount of oxygen trees pump into our atmosphere, and contaminating water bodies through soil erosion. CLIMATE CHANGE The burning of fossil fuels for energy production yields greenhouse gases, including carbon dioxide, which contribute to climate change. Destruction of our forests for wood and paper supplies also contributes to climate change. We are not only concerned here with the carbon footprint within the interior fit-out but also with the carbon footprint used in the entire life cycle of each product in the space. This includes the footprint to extract or harvest, manufacture, transport, and install products in the space as well as the footprint associated with maintaining them and then deconstructing and disposing of them at the end of their useful life in the space. 07_9780470889015_ch04.qxd:WILEY 9/19/11 10:17 AM Page 25 SUSTAINABLE MATERIALS PRINCIPLES Sustainable design is based on basic principles that can guide decision making. The triple top line: This seeks to balance people, plants, and prosperity. Keep in mind not only first costs but also the longer-term costs of ownership, environmental stewardship, and human factors (e.g., consider health and comfort with every decision). The cleanest energy is that which is never used. Select products that support energy efficiency through their function. SUSTAIN ABLE D E SI G N BASI CS working within an existing building). When designing an interior in a new building, there may be opportunities to reuse items from other buildings, salvage yards, or antique dealers. Once all opportunities for material reduction and reuse have been exhausted, it is then appropriate to consider selecting materials with high recycled content and those materials that are easily recyclable at the end of their useful life. DESIGN CONSIDERATIONS As examples of these principles in practice, certain design considerations are the keys to successful sustainable interiors projects. Minimize the life cycle carbon footprint. Select products that have a relatively low carbon footprint over their life cycle when compared to higher-footprint alternatives; the target is zero carbon footprint. Select products that minimize fossil fuel–generated energy use in their production and transportation through conservation, efficiency, and renewable energy. The total footprint includes the embodied carbon footprint involved in manufacturing the product as well as the footprint to maintain the product over its useful life. Find the right building: Check on a potential site’s energy performance on the Energy Star Web site. Evaluate it for its access to public transportation as well as space planning possibilities (e.g., do floor plates allow for penetration of natural light?). Reduce, reuse, recycle—in that order. First, look at ways to reduce the amount of space needed or of materials in a space. Then research opportunities to reuse elements (partition walls, furniture, doors, hardware, etc.) that are already in the space (when Negotiate with the landlord: Encourage the tenant to negotiate a triple net lease in which the tenant pays all taxes, insurance, and maintenance expenses, as well as rent, and install individual meters for at least plug loads and light loads. Take less space: Using less square footage allows more room for amenities and can save money on rent and construction as well as on the long-term lease and energy costs. Focus on internal energy loads: Almost 75% of the energy used in a building is determined by the tenants’ use of electricity. Rethink lighting loads and plug loads. Focus on air distribution for better comfort, energy, and flexibility: One example is displacement ventilation, which can include underfloor air delivery as well as at low points along the walls (side wall delivery). Focus on the human work space: By focusing on space configuration and human factors early in the design, concepts develop that balance open office with closed office and collaboration spaces throughout the office. Consideration of lower panels on workstations will allow daylight and views; it is increasingly considered important to provide all employees with direct access to views and daylight. Consider design for disassembly: This means having an afterlife plan for what is put into a space. Can it be recycled? Does the manufacturer have a take-back program? Is it glued together (a problem) or is it able to be taken apart easily to separate into its various components? Can demountable, easily adjustable wall panels be used? Measure success and lessons learned: Use postoccupancy evaluation and other forms of continual feedback that focus on human performance impacts. Manage resource use through real-time measurement of actual energy and water use by metering. SUSTAINABILITY STRATEGIES ENERGY The design of interiors often fails to focus on simple and effective strategies to reduce the daily energy use of the space. The three most critical considerations to focus on are lighting, thermal comfort and ventilation, and appliance loads. Efficient lighting: Employ daylight-responding dimmable fixtures, minimize incandescent lights where possible, and use compact fluorescent lamps (CFLs) or light-emitting diode (LED) fixtures. Connect lighting controls to occupancy and daylight sensors for both ambient and task lighting. Energy-efficient thermal comfort and ventilation: Recognize that the mechanical systems provide not only thermal comfort but also lifegiving oxygen. Employ time-scheduled thermostat settings, and better understand the comfort ranges of interior users. Appliance loads: The design team has a great deal less control of the plug loads for the interior space, but can help create a positive energy footprint through the selection of major appliances. Specify Energy Star–rated kitchen appliances, electronics, specialty lighting, commercial food service, and office computational equipment. LIGHTING AND DAYLIGHT The mantra “light surfaces and not space” is a well-considered starting point. Lighting design needs to reflect the program and its time-of-day operations, as well as the compass orientation of the space. Perimeter zones can employ controls that set the electrical lighting to take advantage of daylight. Interior zones need to explore bouncing daylight into spaces, as well as implementing occupancy sensors to turn off electrical lighting. Human factors research is increasingly focusing on better work practices by virtue of both the location of light sources and the light levels. Task lighting is preferable for older users of the space so that they can modify the light for the variety of tasks performed at their workstations. Computer work is especially prone to disruption by glare or overly high ambient light levels. The finishes of the furniture, the reflective nature of the dropped ceiling, and the color of the walls that surround the light source can accentuate light diffusion or conversely create a glare issue; the whole interior environment partakes in effective lighting. WATER Interior environments employ a number of fixtures and features that use water. With freshwater resources increasingly valued, the fundamental approach is far less use of potable water where it is not required. For fountains and sinks, the design might employ hands-free sensor controls with aerator faucets. Restroom or individual private water closet facilities can employ dual-flush or lowflow toilets and urinals. Waterless urinals or super low-flow urinals are also available. Other sources of water for nonpotable uses might be employed for interior needs. Rainwater and condensate from HVAC equipment are now used for irrigation and occasionally for waste removal in toilets. S U STAINA B L E M AT E RIALS The standard product selection process involves weighing a variety of criteria, including aesthetics, performance, and cost. Environmental and health impacts present additional considerations in the materials selection process. It is important to realize that there may be tradeoffs between two or more considerations; in other cases, there may be synergies. Raw materials: • Is the product made from virgin materials? • If so, what was the impact of its extraction or harvest on the local ecosystem and is the material finite or renewable? Salvaged, refurbished, or reused materials: • Is the product a salvaged or refurbished material? • If so, was there minimal impact in refurbishing the material? Recycled content: • Does the product contain any preconsumer and/or postconsumer recycled content? • If so, what are the percentages of each? Forest Stewardship Council (FSC)–certified wood: • Is the product certified by the Forest Stewardship Council (FSC)? • Ask for the product’s chain-of-custody number. Local materials: Local materials are often defined as those extracted and manufactured within 500 miles of the project site. • Where are the materials harvested or extracted? • Where are the materials manufactured? Rapidly renewable materials: Rapidly renewable materials are typically defined as those that substantially replenish themselves faster than traditional extraction. In addition, the material harvesting does not result in significant biodiversity loss, increased erosion, or air quality changes. As a general rule of thumb, consider materials that renew within a 10-year cycle. • Is the material made from rapidly renewable resources? Low-emitting materials: • Does installation of the material pose any health risk to installers? • Is this type of product known to support microbial growth? Materials should not be used in an application that will encourage the growth of mold, mildew, or other microbes. • For systems furniture and seating, is the product certified by the GREENGUARD Environmental Institute or has it been tested by another third party? If so, by whom and to what standard? 25 07_9780470889015_ch04.qxd:WILEY 26 9/19/11 10:17 AM Page 26 S U STA INA B L E D E SIGN BASICS LOW-EMITTING PRODUCT STANDARDS 4.2 PRODUCT STANDARD Aerosol adhesives Green Seal Standard GS-36 Adhesives, sealants, and sealant primers South Coast Air Quality Management District (SCAQMD) Rule 1168 Architectural paints and coatings Green Seal Standard GS-11 for volatile organic compound (VOC) limits for specific types Anticorrosive and antirust paints Green Seal Standard GC-3, Anti-Corrosive Paints (not to exceed VOC limit of 250 g/L) Clear wood finishes, floor coatings, stains, primers, and shellacs applied to interior elements VOC limits listed in South Coast Air Quality Management District (SCAQMD) Rule 1113 INDOOR AIR Q UALITY • Does the manufacturer employ energy-saving strategies in the transportation of materials? For example, does it only ship full loads? • Does the manufacturer use fuel-efficient and/or alternative fuel vehicles to transport products? What modes of transportation are used? LIFE CYCLE ANALYSIS—CLOSED-LOOP MODEL 4.3 Waste minimization: Optimize design to minimize installation waste and/or material that is sent to a landfill. • Has the manufacturer implemented any sort of program to minimize waste in the way it manufactures, packages, and installs its products? • Can installation waste, if any, be easily recycled by the manufacturer or at a local facility? Durability and flexibility: Select products that are suited to their use and are long-lasting. Use carpet squares as they are easy to maintain and allow for selected replacement. Carpets CRI Green Label Plus Carpet cushion CRI Green Label Composite wood No added urea-formaldehyde (UF). Consider products (particleboard, availability, lead times, and potential cost MDF, laminates) premiums. Find alternative to plastic laminates. Manufacturing process: • Does the manufacturer employ any best practices in its manufacturing facilities to minimize energy, water, and raw material consumption? • Has the manufacturer eliminated any harmful emissions, including greenhouse gases such as carbon dioxide (CO2), sulfur oxides (SOx), and nitrogen oxides (NOx)? Any reductions in this area have a positive impact on the product’s total embodied carbon footprint and life cycle assessment. Embodied energy: Embodied energy calculations quantify the total energy consumption embedded in a particular material, from raw material acquisition and manufacturing through transportation to point of use. The more processing associated with a given material, the greater is its embodied energy. Source: Adapted from Sigi Koko, Down to Earth, Arlington, Virginia, with additions by Gensler. • Has the manufacturer calculated the embodied energy of the product and within what parameters was it measured? Life cycle assessment (LCA): LCA examines environmental and health impacts from “cradle to grave,” that is, from acquisition of raw materials through end-of-use recovery. A cradle-to-cradle approach closes the acquisition loop. • Has the manufacturer performed any type of life cycle assessment of the product? If so, ask for the LCA report. I N D O O R A IR QUA L ITY Indoor air quality (IAQ) refers to the quality of air inside buildings where people work or live. Air quality is essential for comfort and productivity; most important, good air promotes good health. IAQ can be compromised under the following four conditions: • Inadequate ventilation that does not provide enough outside air • Chemicals used in cleaning and office products that are trapped inside a building • Outdoor pollutants that enter and are trapped inside the building • Mold or other microorganisms that grow, multiply, and disperse particles through heating, air conditioning, and ventilation systems ENVIRONMENTAL QUALITY TERMS The following terms relate to the environmental quality of products used in buildings and elsewhere. • Biodegradable : The ability to completely break down into benign, organic components. • Carcinogen : A substance identified as causing cancer. A carcinogen is classified as “known,” “probable,” “presumed,” or “suspected,” depending on test study data. • Downcycling : Recycling into a product that has less value or is considered more disposable than the original. • Off-gassing : The vaporization of chemical compounds into surrounding air. • Postconsumer : Waste material that has served an intended use in the consumer market. • Preconsumer : Waste material from manufacturing processes that has not yet made its way into the consumer market. • Toxicity : The degree to which a material causes or threatens to cause adverse health effects to living organisms, expressed in exposure limits. • Volatile organic compound (VOC) : A chemical compound that contains carbon and that partially vaporizes at normal room NOTE 4.3 Recovery of materials at end of use provides raw material for new products. temperature. VOCs are a group of chemicals that have varying degrees of toxicity and effects. Significant health hazards from indoor pollution are now being addressed as a serious problem. Poor indoor air quality and its role in sick building syndrome (SBS) and building-related illness (BRI) have been declared by the U.S. Environmental Protection Agency (EPA) as the country’s number one environmental health problem. SICK BUILDING SYNDROME SBS describes a wide range of physical afflictions, which often are similar to mild allergic reactions, and which usually result from exposure to contaminants in indoor air (although noises and other environmental factors can contribute, as well). The specific causes are not identified, but the symptoms coincide with time spent in a particular building and disappear once the sufferer leaves. A BRI describes the same range of ailments, from mild allergic reactions to more serious infections such as pneumonia, except it applies in cases where the specific cause is known. Both SBS and BRI are largely the result of poor indoor air quality. Specific interior IAQ hazards of which to be aware include the following: Microorganisms, dust, and pollen: Though bacteria and fungi are present everywhere in both outdoor and indoor environments, office buildings are especially vulnerable, as they provide areas of high humidity and standing water in circulation and air conditioning ducts, ceiling tiles, insulation, and even ice machines. Sensitive people, such as elderly people, infants, and children or those with weaker immune systems, can be at risk of serious infection. Respirable particles are defined as particles less than 10 microns in diameter (the diameter of a human hair is about 100 microns). Because of their minute size, however, respirable particles flow easily through the nasal passage and can be inhaled deeply into the lungs, where they can cause coughing, wheezing, and even respiratory tract infection. In an office, respirable particles are given off by everything from human skin to the carbon from copy machines. Volatile organic compounds (VOCs): At room temperature, synthetic organic chemicals release vapors and gases called VOCs. Consistently found at higher levels indoors, VOCs come from many different sources, including building materials, consumer products, and combustion sources such as car engines and heating systems. The use of strong office cleaning products, paints, glues, and photocopiers intensifies the problem. Though not all are as seriously harmful, many do cause discomfort and are found nearly everywhere in offices. One major VOC irritant is formaldehyde, a pungent gas that exists in nearly 3,000 different products, including certain floor adhesives, wallcoverings, particleboard, and furniture. Carbon monoxide (CO) is an odorless, colorless gas. Carbon monoxide is given off by fuel-burning engines, such as those in cars, and adjacent buildings can be contaminated if they are not properly ventilated. Prolonged exposure of employees decreases the oxygencarrying capacity of their blood, resulting in shortness of breath, fatigue, and nausea. CO can also cause health problems and even death in homes where garage fumes are not properly ventilated. PERSONAL CONTROL A degree of personal control allows the inhabitant to fit the space to his or her needs; this produces better work performance. Methods include thermal or ventilation control, facilitated by smaller HVAC zones with thermostats, raised floor distribution with individual controlled floor diffusers or operable windows, ambient or task light control, and glare control at outside windows. 07_9780470889015_ch04.qxd:WILEY 9/19/11 10:17 AM Page 27 INTERIOR RATING SYSTEMS AND CERTIFICATIONS SUSTAIN ABLE D E SI G N BASI CS QUALITY OF INTERIOR ENVIRONMENT 4.4 I N T E R IO R R AT ING SYSTEMS AND CERTIF ICATIONS U.S. GREEN BUILDING COUNCIL The U.S. Green Building Council (USGBC) was established in 1993 as a national nonprofit organization, with a voluntary, diverse membership that operates on consensus principles. USGBC works with members to incorporate their ideas into the overall organization. The consensus of USGBC members is to work together to promote green building and to foster greater economic vitality and environmental health. USGBC accomplishes this by working with the building construction industry to help bridge ideological gaps, thus providing benefits for the entire construction community. able design projects. LEED serves as a tool to aid integrated sustainable design and to help owners and design teams obtain benefits in the overall health and efficiency of building design. LEED is based on accepted energy and environmental principles, many of which are described elsewhere in this section. It strikes a balance between known effective practices and emerging concepts. As of 2010, each LEED rating system is structured into seven credit categories, each of which is, in turn, composed of individual credits and prerequisites that, in aggregate, allow a participant to achieve one of four levels of certification as defined by USGBC. LEED FOR COMMERCIAL INTERIORS LEED RATING SYSTEM One of the many achievements of USGBC is the establishment of the Leadership in Energy and Environmental Design (LEED) rating system. Launched in 2000, LEED is a voluntary point-based rating system that establishes consistent evaluation criteria for sustainContributors: Adapted by Rives Taylor and Nellie Reid, Gensler, Houston, Texas, from Tom Revelle, Humanscale, New York, New York. There are several different LEED rating systems for various types of projects. LEED for Commercial Interiors (LEED CI) was developed for interior design projects in existing and new buildings. It is structured into the same seven credit categories as the other versions, but the requirements have been customized to reflect the scope of work typical in an interiors project. The site credits and some of the water and energy credits relate to the sustainable building attributes of the base building selected, whereas most of the materials and indoor environmental quality credits relate to sustainable attributes of the interior fit-out. All prerequisites must be met in order to be eligible for a LEED rating. Innovation credits are available to those projects exceeding the requirements of other LEED credits and can also be used for innovative strategies that were not captured in other credit areas. Innovation credits provide project teams with the opportunity to receive additional points for exceptional performance on other LEED credits (e.g., 50% water use reduction) and/or innovative strategies not specifically addressed by other LEED credits (e.g., a sustainable education program). There are unlimited possibilities for innovation credits. Regional priority credits were introduced in 2009 for each region to determine which credits receive more weight, depending on regional energy, environmental, and health priorities. Many of the credits relate directly to strategies covered earlier in this section. 27 07_9780470889015_ch04.qxd:WILEY 28 9/19/11 10:17 AM Page 28 S U STA INA B L E D E SIGN BASICS INTERIOR RATING SYSTEMS AND CERTIFICATIONS LEED FOR HOMES OTHER GREEN BUILDING RATING SYSTEMS 4.5 RATING SYSTEM REGION WHERE USED WEB SITE ADDRESS BREEAM United Kingdom, European Union, Middle East CASBEE Japan http://www.breeam.org/ http://www.ibec.or.jp/CASBEE/english/overviewE.htm Green Globes Canada, United States http://www.greenglobes.com/ Green Star Australia http://www.gbca.org.au/ Energy Star United States http://www.energystar.gov/ LEED for Homes is a rating system that promotes design and construction of high-performance homes, which use less energy, water, and natural resources; create less waste; and are more durable and comfortable for their occupants. The LEED for Homes rating system, which was released in 2008, lists intents and requirements for each credit and includes the LEED for Homes Project Checklist, along with corrections that were issued in 2010. The Checklist helps project teams track their credits against requirements for certification. LEED for Homes continues to develop and expand its areas of activity. It is developing a Midrise Pilot project for residential projects in the four- to six-story category. The LEED for Homes Initiative for Affordable Housing seeks to recognize and reward the intrinsic resource efficiencies of affordable housing within the LEED for Homes rating system. The American Society of Interior Designers’ Foundation has partnered with USGBC to launch REGREEN, the nation’s first green residential remodeling guidelines. Contributors: Rives Taylor, Gensler, Houston, Texas. Nellie Reid, Gensler, Santa Monica, California. 08_9780470889015_ch05.qxd:WILEY 9/19/11 10:18 AM Page 29 DESIGN BASICS 5 E V ID E NCE - BA SE D D ESIGN Evidence-based design (EBD) is an approach to design that seeks to create better design outcomes by basing decisions on credible research. It adds knowledge from many sources, including the computational, social, and natural sciences, to individual experience and intuition. EBD goes beyond the analysis of specific projects, and increases the designer’s ability to predict the effects of design decisions. Clients and communities who are responsible for allocating resources are demanding to know how design decisions will affect the performance of buildings. Design professionals are under increasing pressure to demonstrate how their work will positively influence human well-being and effectiveness, and support the health of the planet. Evidence-based design relates to the value of design as a contributor to society, as well as its aesthetic value. This will require multidisciplinary collaboration and sharing. Developing research-savvy professionals who can develop and use knowledge bases begins with design education. The development of evidence-based design will require the establishment of clear and accepted standards and guidelines about what constitutes credible evidence. In order to achieve these ends, the design professions must develop research standards and protocols that will develop, apply, and disseminate evidence-based research. COMPUTATIONAL RESEARCH Using design research from computational sources consists of an iterative process of modeling, simulation, and data mining. Modeling connects physical action with the brain by creating simplified physical and virtual models of objects being investigated by designers. Simulation creates a computational version of the model to aid in understanding the performance of parts in the context of the whole system. Data mining extracts hidden relationships from large databases of personal experience, completed project records and documentation, and other sources. Modeling and simulation tools used for integrated practice delivery (IPD), such as building information modeling (BIM), represent a virtual building and its related design and construction data. What is needed is an infrastructure to capture, share, and understand data across design and other professions. SOCIAL SCIENCE RESEARCH The social sciences seek to understand human behavior through scientific exploration. Design research from sources in the social sciences derives primarily from environmental psychology and from sociology’s study of developmental and cognitive psychology. The social sciences provide ways to study relationships between places and human behavior. They result in knowledge about why and how people respond to their physical surroundings. PHYSICAL AND NATURAL SCIENCE RESEARCH The physical sciences, in particular physics, have long been involved in the design of architectural structures, mechanical and electrical systems, and building performance. Research in designrelated subjects has been spurred by the need for innovation in energy conservation, sustainably designed building systems, and sustainable materials. In the natural sciences, biology—specifically neuroscience—is opening a world of information on how and why the brain responds to environmental stimuli and experiences. Scientists can now see what parts of the brain respond to light, sound, scale, proportion, and perspective. They can connect human physiology with emotions and see the effects of stress. The data produced makes it possible to predict the impact of physical building attributes on human performance. The relationship of neuroscience to architecture has been explored in Architecture and the Brain by John P. Eberhard, FAIA (Oxford University Press, 2009). BUILD ING CO D E S CODES AND REGULATIONS AFFECTING INTERIORS Codes and regulations that affect interior design include requirements at the local, state, and national level. The legal entities that have adopted the code are commonly referred to as the authorities having jurisdiction. Although some jurisdictions write their own codes, most adopt one of the model codes promulgated by code-writing organizations that write, update, and publish a code and related material. The local jurisdiction may add local amendments to the model code to account for regional differences. In the United States, the International Building Code (IBC), first published by the International Code Council (ICC) in 2000, has been adopted by all 50 states. The ICC also publishes other related international codes, including the International Residential Code, International Mechanical Code, International Plumbing Code, and others. OTHER REGULATIONS In addition to the IBC, the following regulations may affect an interior design project: • Local agency requirements such as municipal health department rules and regulations: For example, a local health department may have rules governing finishes for restaurants. • State or federal agency requirements that govern specific building types: These may include codes for schools, prisons, and health facilities, as well as regulations governing federal facilities. • Energy codes: These are usually adopted at the state level, but local authorities may require additional energy conservation measures. • Flammability regulations: In addition to model code requirements, cities or states may adopt standards regulating flammability for furniture, draperies, and interior finishes. • Federal regulations: These include federal laws, such as the Americans with Disabilities Act (ADA), as well as regulations published in the Code of Federal Regulations, such as the regulation for safety glazing. • Standards adopted by reference: All model codes adopt, by reference, standards developed by hundreds of trade associations, testing agencies, and standards-writing groups, such as the American Society for Testing and Materials (ASTM). • Indoor air quality: Local or state requirements for indoor air quality may limit the amount of outgassing of certain materials, limit the use of materials with volatile organic compounds (VOCs), or require certain levels of ventilation. 08_9780470889015_ch05.qxd:WILEY 30 9/19/11 D E SIG N B A SICS 10:18 AM Page 30 BUILDING CODES INTERNATIONAL BUILDING CODE PROVISIONS The International Building Code (IBC) 2009 edition presents model code regulations that safeguard the public health and safety, and is the source of the references used here. The sections of the IBC included here have been selected for their applicability to student projects. Actual professional design projects are subject to codes adopted by the authorities having jurisdiction. USE AND OCCUPANCY CLASSIFICATION (IBC CHAPTER 3) Chapter 3 of the IBC establishes one or more occupancy classifications based on the anticipated uses of a building. These classifications are necessary to properly apply many of the code’s nonstructural provisions. Occupancy refers to the use of the building or interior space. Occupancies are based on occupant- and content-related hazards and the life-safety characteristics of the building. Occupant-related hazards include considerations such as the number, density, age, and mobility of the occupants. Buildings or portions of buildings may consist of more than one occupancy, in which case the code may require fire separation between the occupancies. separated with fire barrier walls or horizontal assemblies, or both, with an hourly rating defined by the code. Hourly ratings range from one hour to four hours. OCCUPANCY SEPARATION 5.2 Because many other requirements of building codes are based on occupancy, one of the first steps in code-conforming design is to determine the occupancy classification. If the classification of a project is unclear, consult the local building officials. MIXED OCCUPANCIES When a building or portion of a building contains two or more different occupancies, it is considered a mixed occupancy. The code requires that particular combinations of adjacent occupancies be OCCUPANCY CLASSIFICATION 5.1 OCCUPANCY A-1 DESCRIPTION Assembly usually with fixed seats for the viewing of performances or movies EXAMPLES Movie theaters, live performance theaters, TV and radio studios with audience A-2 Assembly for food and drink consumption Restaurants, bars, clubs, banquet halls CONSTRUCTION TYPES (IBC CHAPTER 6) A-3 Assembly for worship, recreation, or amusement, and similar activities not classified elsewhere Libraries, art museums, churches, courtrooms, conference rooms for more than 50 people, lecture halls A-4 Assembly for viewing of indoor sporting events with spectator seating Arenas, swimming pools, skating rinks, tennis courts IBC Chapter 6 deals with classification as to construction type, based on a building’s materials of construction and the level of fire resistance provided by such materials. A-5 Assembly for participation in or viewing outdoor sports Stadiums, amusement park structures B Business for office or service transactions Offices, educational functions above 12th grade, banks, outpatient clinics, ambulatory health care facilities E Educational use by more than five people for grades 12 and lower Grade, middle, and high schools, day care for more than five children over 2.5 years old F-1 Factory of moderate-hazard uses that is not classified as an H occupancy Bakeries, woodworking shops, some manufacturing F-2 Factory of industrial low-hazard uses that include the use of noncombustible materials and uses that do not cause a significant fire hazard. Manufacturer of nonalcoholic beverages, brick and masonry, ceramics, glass, gypsum, metal products, etc. H H-1 detonation hazard, H2 accelerated burning, H-3 materials that readily support combustion or pose a physical hazard, H-4 health hazards, H-5 semiconductor fabrication facilities Flammable liquids, explosives, and other hazardous physical materials I-1 Housing for more than 16 persons, on a 24-hour basis, who because of age, mental disability, or other reasons, live in a supervised residential environment that provides personal care services Residences where occupants are capable of responding to an emergency situation without physical assistance from staff. Assisted living, halfway houses, group homes, rehab centers I-2 Medical, surgical, psychiatric, nursing, or custodial care on a 24-hour basis of more than five persons who are not capable of self-preservation Hospitals, nursing homes, mental hospitals I-3 Facilities for more than five persons who are under restraint or security and who are generally incapable of self-preservation because of security measures not under the occupant’s control Prisons and jails, reformatories, detention and correctional centers, prerelease centers I-4 Adult care facility for more than five unrelated adults, where occupants are not capable of achieving self-preservation, that provides care for less than 24 hours a day and provides supervision and personal care services A facility where occupants are capable of responding to an emergency situation without physical assistance from the staff is classified as Group R-3. M Mercantile for the display and sale of merchandise Department stores, retail or wholesale stores, sales rooms, markets, drug stores R-1 Residential occupancies containing sleeping units where occupants are transient in nature Hotels, transient boarding houses, motels R-2 Multiple sleeping units where occupants are primarily permanent Apartments, live/work units, dormitories, hotels, motels R-3 1- and 2-family dwelling, or adult and child care facilities that provide accommodation for five or fewer persons of any age for less than 24 hours Houses, duplex units, townhouses, condominiums; adult and child day care. Congregate transient living facilities with 10 or fewer occupants are permitted to comply with construction requirements for Group R-3 R-4 Residential care/assisted living for 6 to 16 residents, excluding staff for 24 hours per day Small assisted living centers S-1 Moderate-hazard Storage Aircraft and motor vehicle repair; storage of flammable materials S-2 Low-hazard Storage Aircraft hangers, storage of nonflammable materials, parking garages U Building or structure of accessory character Barns, carports, greenhouses, private garages, sheds Every building is classified into one of five types of construction, based on the fire resistance of certain building components. Four of the types are further subdivided into two groups, using the suffixes A and B. The building components include the structural frame, interior and exterior bearing walls, floor and roof construction, and exterior walls. • Type I and II buildings must be constructed of noncombustible materials. • Types III, IV, and V are considered combustible. • Type I buildings are the most fire-resistive. • Type V buildings are the leas fire-resistive. Construction type can affect the required fire ratings of the structural frame, bearing walls, floor and roof construction, and protection of openings where required by other IBC provisions. Generally, interior nonbearing partitions require one-hour construction, unless otherwise noted in the code. BUILDING ELEMENTS 5.3 08_9780470889015_ch05.qxd:WILEY 9/19/11 10:18 AM Page 31 BUILDING CO D E S MEANS OF EGRESS (IBC CHAPTER 10) IBC Chapter 10 presents the criteria for regulating the design of the means of egress as the primary method of protection for people in buildings. The chapter uses both prescriptive and performance language to provide a basic approach to determining a safe exiting system for all occupancies. GROUND-LEVEL EGRESS 5.4 EGRESS COMPONENTS OCCUPANCY MAXIMUM OCCUPANT LOAD A, B, E, F, M, U 50 H-1, H-2, H-3 A means of egress is a continuous and unobstructed path of vertical and horizontal egress travel from any point in a building to a public way. Once the overall exiting plan is developed, the follow must be done: Determine the occupant load Determine the number of exits required Verify the length of the common path of egress travel Verify the maximum travel distance Determine the arrangement of exits Calculate the width of exits Check for dead-end corridors load, the code recognizes that two exits are not necessary. Factors that contribute to the different numbers include concentration and mobility of occupants and the presence of hazardous materials. SPACES WITH ONE MEANS OF EGRESS 5.6 Designing an egress system requires planning the spaces and components that allow an occupant to safely exit a building during an emergency, and detailing the individual parts of the system to meet the requirements of the code. • • • • • • • D E SI G N BASI CS 3 H-4, H-5, I-1, I-3, I-4, R 10 S 30 MINIMUM NUMBER OF EXITS FOR OCCUPANT LOAD 5.7 OCCUPANT LOAD UPPER-LEVEL EGRESS 5.5 MINIMUM NUMBER OF EXITS 1 to 500 2 501 to 1,000 3 More than 1,000 4 DEAD-END CORRIDORS A dead end is a corridor or an exit path that has only one way to exit. Generally, dead ends are limited to 20 ft (6 m). IBC 2009 permits the maximum length of dead-end corridors to be 40 ft in sprinklered buildings in Group B, E, F, I-1, M, R-1, R-2, R-4, S, and U occupancies. Chapter 10 of the IBC uses a zonal approach to egress as a basis for regulation of exit access, exit, and exit discharge portions of the means of egress. EXIT ACCESS The exit access is that portion of the means of egress that leads to DEAD-END CORRIDOR 5.8 the entrance to an exit. It is generally the most distant part of the building from safety. Exit access areas may include components such as rooms, spaces, aisles, intervening rooms, hallways, corridors, ramps, and doorways. In some cases in the IBC, the exit access is required to be a protected path of travel. The exit access is the portion of the building where travel distance is measured and regulated. EXIT The exit is the portion of the egress system that provides a protected path of egress between the exit access and the exit discharge. Exits are fully enclosed and protected from all other interior spaces by fire-resistance-rated construction with protected openings (doors, glass, etc.). Exits may be as simple as an exterior exit door at ground level or may include exit enclosures for stairs, exit passageways, and horizontal exits. Exits may also include exterior exit stairways and ramps. Depending on building height, construction type, and passageway length, exits must have either a one- or two-hour rating. OCCUPANT LOAD The occupant load is the number of people that the code assumes will occupy a building or portion of a building for egress purposes. Occupant load is dependent on the occupancy classification of the building or space and assumes that certain types of use will be more densely occupied than others, and that exiting provisions must respond accordingly. EXIT DISCHARGE The exit discharge is the portion of the egress system between the Occupant load is determined by the largest number established by one of the following conditions: termination of an exit and a public way. The exit discharge may also include building lobbies of multistory buildings if one of the exit stairways opens onto the lobby and certain conditions are met. • The number of occupants calculated using the occupant load factors given in the code based on the intended use and size of the space. (This is the method most commonly used.) • The actual number of occupants a space is designed to serve. • The number of occupants, by combination, used when occupants from adjoining spaces egress through an area. PUBLIC WAY A public way is any street, alley, or similar parcel of land essentially unobstructed from the ground to the sky that is permanently appropriated to the public for public use and having a clear width of not less than 10 ft (3 m). The IBC provides Occupant Load Factor Tables to determine the maximum floor area allowed per occupant, based on the building and occupancy type. ACCESSIBLE EGRESS ROUTE If components of the egress system are part of an accessible route, they must conform to all the requirements of the 2010 ADA Standards for Accessible Design, which may be more stringent than the IBC requirements. NUMBER OF EXITS The number of means of egress required from a room or area depends on the occupant load and the occupancy. Rooms or areas are permitted to have only one exit or exit access doorway until they exceed a certain occupant load. When the occupant load becomes very large, additional exits may be required. The reason for requiring two or more means of egress is to allow alternate means of egress in case one exit is blocked by fire. However, when there are small spaces or areas with limited occupant COMMON PATH OF EGRESS TRAVEL The common path of egress travel is the portion of an exit access that the occupants are required to traverse before either there is a choice of exits or two paths merge to become one. The length of the common path is measured from the most remote point of a room or area to the nearest point where more than one exit path is available. Common paths of egress travel must be included within the permitted travel distance. If furniture or equipment is located in the area, it may be necessary to measure the common path of travel around the furniture instead of on a straight path. Even if two exits are not required based on occupant load, if the common path of travel exceeds the allowable distances, then two exits from a space are required. 31 08_9780470889015_ch05.qxd:WILEY 32 9/19/11 D E SIG N B A SICS 10:18 AM Page 32 BUILDING CODES EXITS THROUGH INTERVENING SPACES COMMON PATH OF TRAVEL 5.9 OCCUPANCY OCCUPANT LOAD NONSPRINKLERED BUILDING, FT (M) SPRINKLERED BUILDING, FT (M) A, E, I-1, I-2, I-4, M, R, U — </= 75 (22.9) </= 75 (22.9) B, F, S B, S <30, > 3,075 </= 75 (22.9) </= 100 (30.5) B, S, U </= 3,075 </= 100 (30.5) </= 100 (30.5) B, S >30 </= 75 (22.9) </= 100 (30.5) H-1, H-2, H-3 — — </= 25 (7.6) H-4, H-5 — — </= 75 (22.9) I-3 — </= 100 (30.5) </= 100 (30.5) U >30 </= 75 (22.9) </= 75 (22.9) COMMON PATH OF EGRESS TRAVEL 5.10 ARRANGEMENTS OF EXITS When two exits or exit access doorways are required, they must be separated enough so that if one becomes blocked, the other is available for use. In nonsprinklered buildings, two exits or exit access doorways must be placed a distance apart equal to not less than one-half of the length of the maximum overall diagonal dimension of the room or area to be served. In sprinklered buildings, the minimum distance is one-third the diagonal dimension of the room or area to be served. If the room or area is irregular in shape, the dimension that gives the greatest length should be used. Egress paths may pass through an adjoining room or area only if it is accessory to the area served, is not a high-hazard occupancy, and provides a discernible path of travel to an exit. Egress paths in commercial spaces may not pass through kitchens, storerooms, closets, or spaces used for similar purposes, nor may they pass through rooms that can be locked to prevent egress. Egress from dwelling units or sleeping areas may not pass through other sleeping areas, toilet rooms, or bathrooms. An egress path may pass through a kitchen area that serves adjoining rooms that are part of the same dwelling unit or guest room. WIDTH OF EXITS According to IBC 2009, the total means of egress width is determined by multiplying the total occupant load served by the means of egress by 0.3 in. (7.62 mm) per occupant for stairways and by 0.2 in. (5.08 mm) per occupant for other egress components. When multiple exits are required, they must be sized so that the loss of one will not reduce the required exit width by more than 50%. The maximum capacity from any story of a building must be maintained to the termination of the means of egress. DOOR ENCROACHMENT When exit enclosures are connected with a one-hour fire-resistance-rated corridor, the required exit separation is measured along a direct line of travel in the corridor. The walls of the exit enclosures must be a minimum of 30 ft (9.1 m) apart at any point in a direct line of measurement. According to IBC 2009, doors when fully opened and handrails cannot reduce the required means of egress width by more than 7 in. (178 mm). Doors in any position must not reduce the required width by more than one-half. Other nonstructural projections such as trim and similar decorative features are permitted to project into the required width a maximum of 1-1/2 in. (38 mm) on each side. EXIT SEPARATION IN A ROOM 5.12 DOOR ENCROACHMENT 5.14 COMMON PATH OF EGRESS TRAVEL WITH FURNITURE 5.11 RESIDENTIAL EXITING EXIT SEPARATION ON FLOOR OR GROUP OF ROOMS 5.13 Both the IBC and the International Residential Code (IRC) require emergency escape and rescue openings in Group R occupancies. The IRC requires basements with habitable space and every sleeping room below the fourth story to have at least one such opening directly into a public street, public alley, yard, or court. Openings may open onto a balcony within an atrium if the balcony provides access to an exit and the dwelling unit or sleeping room has a means of egress that is not open to the atrium. When the emergency escape opening is below grade level, both the IBC and IRC allow window wells, if minimum dimensional requirements are met. 08_9780470889015_ch05.qxd:WILEY 9/19/11 10:18 AM Page 33 PROGRAMM I N G TRAVEL DISTANCE Because exit access areas are not protected, the code limits how far someone must travel to safety. Exit access travel distance is the distance that an occupant must travel from the most remote point in the occupied portions of the exit access to the entrance of the nearest exit. Maximum travel distances are based on the occupancy of the building and whether the building is sprinklered. D E SI G N BASI CS MAXIMUM TRAVEL DISTANCE 5.16 Travel distance is measured in a straight line from the most remote point through doorways, unless furniture or equipment requires a measurement along an actual path of travel. When the path of travel includes unenclosed stairways, the distance is measured along a plane parallel and tangent to the stair tread nosings in the center of the stairway. EXIT ACCESS TRAVEL DISTANCE 5.15 WITHOUT SPRINKLER OCCUPANCY FT (M) A, E, F-1, I-1, M, R, S-1 200 (61) WITH SPRINKLER FT (M) 250 (76.2) B 200 (61) 300 (91.4) F-2, S-2, U 300 (91.4) 400 (122) H-1 Not permitted 75 (22.9) H-2 Not permitted 1,100 (335.3) H-3 Not permitted 150 (45.7) H-4 Not permitted 175 (53.3) H-5 Not permitted 200 (61) I-2, I-3, I-4 150 (45.7) 200 (61) P RO G R A M M ING Architectural programming is the process of identifying and defining user requirements before proceeding with design development. The goal is to develop and document the client’s business system and his or her needs. During the process, the analyst also gathers information on what is, and is not, currently working, and what exists, or needs to exist, for the client to carry out his or her purpose or mission. In the field of architecture, these needs are related to space requirements, which, when completely defined, are referred to as the architectural program. Unless the designer completely understands the needs and uses of a space, the resulting design will fall short of the needs of the client and the users of the space. Also, more often than not, an incomplete understanding of client needs results in project cost overruns and design changes. Changes made as a project design is being implemented increase the overall cost of the project. A thoughtful architectural program supports the designer and his or her design by fully capturing the needs of the client. The result is a more effective design that is implemented on time and within budget parameters. Architectural programs have several fundamental components: • Summary of the project scope and program results • Program support analysis, including projections for headcount, conference room utilization, cafeteria, and so on • Business and building analysis, including adjacency diagrams and supporting analysis • Program document, program summary reports, and interview notes • Appendices containing supporting information provided by the client or from related research Architectural programming is the first step in the design process and is, perhaps, the most important phase. Meaningful communication is required to assess, review, refine, and document a client’s space requirements. During the programming process, the client’s problems are identified and clarified in order to develop a solution for today and for the future. Programming promotes an understanding of the whole problem, as opposed to symptoms or pieces or parts of the client’s problem. PROGRAMMING PROCESS Reducing the programming process to its most elementary level results in three steps, as follows: 1. Information gathering, which involves research, listening, and learning about the client’s needs. 2. Analyzing and synthesizing, which involves consolidating the acquired information for a full understanding of the client’s problems, needs, options, and potential costs, as well as proposing options and making recommendations. 3. Documentation and validation, which involves documenting the findings, reviewing findings and recommendations with the client, then getting feedback, modifying the program, and reissuing the program document. STEP 1: INFORMATION-GATHERING PROCESS The first step in the programming process, information gathering, consists of three primary activities: the initial meeting, the goalsetting session, and the needs and requirements interviews. ACTIVE LISTENING Active listening is critical to the success of the programmer. Active listening involves quieting the mind and focusing completely on the information being presented. If questions arise, they are quickly asked, then documented in your notes when the speaker has completed all his or her thoughts associated with the previous question. Repeating back to the speaker what was heard, using the listener’s own words, is also a critical part of active listening. It accomplishes two primary goals: first, it gives the speaker confidence that he or she was heard and understood; second, it gives the speaker the opportunity to clarify ideas or points that may have been misunderstood. Advance preparation of questions frees the mind to focus on the speaker and his or her comments. The program is only good if the gathered information is complete and accurate. If we listen well, we increase the probability of generating an effective program. ACTIVITIES • Research client • Acquire floor plans, client organization chart, and current personnel report 33 08_9780470889015_ch05.qxd:WILEY 34 9/19/11 D E SIG N B A SICS 10:18 AM CONTRACT DOCUMENTS • Prepare questions for determining client’s vision and image and for interviews • Walk through site • Facilitate vision-image or goal-setting session • Develop mission statement • Conduct interviews • Gather space demand/utilization information for conference rooms, cafeterias, training rooms, and so on PRODUCTS • Client background and an understanding of who/what the client is today • Documented project goals and vision with mission statement • Interview notes • Marked-up floor plate drawings with notes and updates • Client data, including current personnel report and space utilization reports for conference rooms, cafeterias, training rooms, and so on STEP 2: ANALYSIS AND SYNTHESIS PROCESS After gathering and organizing a comprehensive review of the information, quantitative and qualitative specifics about each required space are extracted, to include the following: • • • • Page 34 Space types Sizes Quantities Design characteristics The result is a fundamental set of space types for both individual organizational groups and common or shared spaces. Space standards (standard workplace sizes to be applied throughout the program) that meet the needs of individual work processes and the building module are developed at this time. Space quantities are developed next. • • • • • • Analyze interview notes Develop flow diagram of business process Identify themes and potential conflicts in needs Resolve conflicts or open issues with client Analyze headcount and develop projections Analyze space utilization reports for conference rooms, cafeterias, training rooms, and so on Develop program, space list, and quantities Analyze interactions and develop adjacency diagram Acquire rentable square footage (RSF) and rentable factors for buildings being examined, or desired factors for potential shell designs Develop stacking and blocking diagrams Perform cost analysis Develop options with associated costs The final step in the process is to document and validate the program. Once the program is complete, a program review meeting is scheduled. The program review may be held at various levels of detail, depending on the client’s personality and project complexity. A signed program acceptance statement from the client is a critical, and often overlooked, part of the process. ACTIVITIES • • • • • • Summarize findings Document findings in report format Review findings, program, and options with client Identify program direction and document program changes Update program and documentation Get client sign-off on program and projections PRODUCTS PRODUCTS • Base program • Headcount projections • Conference rooms, cafeteria, demand/utilization projections Adjacency diagram and other potential diagrams Process flow diagram (optional, based on client need) Stacking and blocking diagrams Program options and costs List of conflicts or issues requiring resolution STEP 3: DOCUMENTATION AND VALIDATION ACTIVITIES • • • • • • • • • • • and training room • • • • • Draft of program report Options analysis Program review meeting notes Revised and final program report Signed program acceptance statement CONTRACT DOCUMENTS CONTRACT DOCUMENTS FOR COMMERCIAL INTERIORS Contract documents describe the proposed construction of furniture, furnishings, and equipment installation. They include written specifications and graphic documentation, such as drawings, which communicate the design of the project. The two sets of contract documents that a designer must prepare for a complete commercial interiors project are the construction contract documents, and the furniture, furnishings, and equipment (FF&E) contract documents. CONTRACT FOR CONSTRUCTION The agreement between the owner and the construction contractor is the contract for construction. The construction contractor is responsible for supervising and directing the construction of the project. This includes providing labor, materials, equipment, tools, water, heat, utilities, and other facilities and safety features. The construction contractor employs the various trades required to accomplish the work of the contract, or makes agreements with subcontractors. In addition to orchestrating various construction activities, construction contractors perform a variety of administrative tasks. The general contractor is usually responsible for securing and paying for the building permit and other permits required for completion of the project. The general contractor is also generally responsible for the preparation of a construction schedule, and must prepare and submit shop drawings and samples for the architect’s approval. The general contractor coordinates the work of subcontractors, such as electricians, plumbers, painters, carpenters, and carpet installers. A subcontractor is a person who is awarded a portion of an existing contract by a principal or general contractor. A subcontractor performs work under a contract with a general contractor, rather than the employer who hired the general contractor. Contributor: Anne Mott; lauckgroup; Dallas, Texas. Shop drawings and samples are not contract documents. They are submitted to demonstrate the way in which the construction contractor intends to accomplish the design expressed by the contract documents. Shop drawings illustrate specific situations or details of a project. They are prepared by the construction contractor, one of the subcontractors, the product manufacturer, or the supplier. Samples include examples of the materials or workmanship. Shop drawings and samples are submitted to the designer for approval, and are used to verify selections and to establish standards by which the completed work will be judged. FURNITURE, FURNISHINGS, AND EQUIPMENT CONTRACTS The furniture, furnishings, and equipment (FF&E) contractor is responsible for procuring, delivering, and installing the goods described in the FF&E contract. The designer typically administers the agreement between the owner and the FF&E contractor. The FF&E contractor is often a furniture dealer but may also be a furniture manufacturer or a design professional. FF&E CONTRACTORS The furniture dealer is the local or regional presence of the manufacturer. The dealer processes the sale and provides various support and follow-up services to the owner. One of the services a dealer typically offers is warehousing the goods until the project site is ready to receive them for installation. Equipment is commonly procured directly from the manufacturer through a direct sales force representing the manufacturer, not the manufacturer’s dealer. For example, a hospital bed manufacturer may not require a showroom to market a relatively expensive product with a limited user base. The sale may be effectively accomplished by sending a sample bed to the hospital on a trial basis or by arranging a tour of the factory showroom. FF&E CONTRACTOR ROLES The FF&E contractor prepares purchase orders based on the FF&E contract. A purchase order is the form used to obtain the required goods for the project. It contains a description of the goods, the supplier’s catalog number, the number of items required, and the price. Separate purchase orders are prepared for each supplier involved in the project. The FF&E contractor coordinates the requirements for customer’s own material (COM), material that is purchased separately from the product and supplied to the product manufacturer for application. “Customer” in this case does not refer to the designer’s customer, the owner, but to the manufacturer’s customer, the party placing the order, which is the FF&E contractor. Large corporations can purchase products—for example, carpet, furniture, fabric, and light fixtures— through their in-house purchasing departments and supply them to the contractor for installation. After the goods have been manufactured, they are packaged for delivery. An invoice, a bill requesting payment for the goods, is prepared by the manufacturer and sent to the FF&E contractor, typically at the same time the goods are shipped. DELIVERY AND INSTALLATION OF FF&E The Uniform Commercial Code (UCC) defines many of the terms, and sets forth the procedures, used in the delivery of goods. Delivery is defined by the UCC as voluntary transfer of possession. Delivery does not necessarily indicate ownership. Title means ownership; if you have title to goods, you own them. For example, a manufacturer delivers furniture to a carrier for transportation to its destination. The manufacturer is not transferring title to the goods; therefore, the carrier does not own the furniture. Receipt is defined as taking physical possession of goods. A carrier is a transportation company. Carriers that operate in interstate commerce are regulated by the Interstate Commerce Commission (ICC). Common carriers offer transportation services to 08_9780470889015_ch05.qxd:WILEY 9/19/11 10:18 AM Page 35 CONTRACT DOCUMENTS D E SI G N BASI CS BUTT JOINT DETAILING PASSAGE OF TITLE 5.17 SELLER ASSUMES EXPENSE AND RISK OF… PASSAGE OF TITLE OCCURS AT… PRICE OF GOODS… F.O.B.: Place of shipment Putting goods into the possession of the carrier place of shipment Place of shipment (typically manufacturer’s factory loading dock) Does not include shipping charges F.O.B.: Place of destination Transporting the goods to the destination Destination (typically the project site’s loading dock) Includes shipping charges the general public. They are usually responsible for the goods they are shipping, whether or not they have been negligent. Contract carriers provide transportation only to those with whom they choose to do business. They do not insure the goods they transport unless they are contracted to do so. Private carriers are not in the transportation business. They own and operate trucks to transport their own goods. The ICC does not regulate private carriers. APPLIED OVERLAY DETAILING MODEL 5.18 Butt joint detailing often requires tight construction tolerances and skilled craftspeople to implement, and is typically more expensive than applied overlay detailing. Butt joints are often subtle, inviting closer inspection and appreciation of their machine-tooled precision. Butt joints are appropriate where the craftsmanship of the construction is as much a part of the design statement as the space that is formed. Care must be taken not only in the construction of most butt joints but often in their maintenance as well. For example, a gypsum board wall without an applied base is more susceptible to damage than a base protected by a resilient or wood base. BUTT JOINT DETAILING MODEL 5.20 With few exceptions, such as when goods are picked up by the buyer, whoever has title to the goods bears the risk of their being lost, stolen, damaged, or destroyed. The risk of loss is commonly indicated by the abbreviation F.O.B., defined by the UCC as “free on board.” F.O.B. at a named place indicates where title to the goods and risk of their loss or damage pass from the seller to the buyer, which is typically the FF&E contractor. The buyer pays the transportation costs from the point named in the F.O.B. “place.” SHIPMENT TRACKING A drop shipment means the goods will be shipped to a destination different from that of the party who ordered and paid for them. A bill of lading is defined by the UCC as a document confirming the receipt of goods for shipment issued by a person engaged in the business of transporting. A packing list is a detailed list of quantities and descriptions of the goods being delivered. It is used to check the items, and it crossreferences the bill of lading. The packing list is typically attached to the outside of the shipping package in a clear plastic envelope. DETAILING CONCEPTS Construction detailing originates from and reinforces the design concept of the space. When designing details for incorporation into the contract documents, designers should show the intent of the detail, not describe how the assembly is to be constructed. It is the general contractor’s responsibility to decide how a detail can best be executed with the available fabrication methods and craftspeople. Sufficient information must be shown on the drawings and described in the specifications to indicate the intent of the design. For details involving structural calculations (for example, handrails), or for complex assemblies involving skilled craftspeople (for example, veneered wood panels), the fabricator prepares shop drawings so that the designer can verify the intent and effect. There are six fundamental methods by which materials meet or change planes: applied overlay, butt joint, reveal, overlap, infill, and warp. APPLIED OVERLAY DETAILING Applied overlay detailing is the traditional detailing method. It calls attention to a change in plane or materials, and has been used to conceal construction tolerances, which can be as much as 1/4 in. (6 mm). This method of detailing is typically the most cost-effective because it often requires less precision and craftsmanship. Applied overlay detailing can be used to highlight components or finishes by framing them with trim pieces. It is often used to give scale to a space by providing a traditional base and cap. TYPICAL APPLIED OVERLAY DETAILS 5.19 TYPICAL BUTT JOINT DETAILS 5.21 35 08_9780470889015_ch05.qxd:WILEY 36 9/19/11 D E SIG N B A SICS 10:18 AM Page 36 CONTRACT DOCUMENTS REVEAL DETAILING Reveal detailing provides relief to planar surfaces by introducing depth and shadows. Reveals can create the illusion of floating. The implied integrity of the material may be illusory, however; veneer wood panels are often used in reveal detailing because of cost considerations. Where this is done, the width of the reveal must be small enough that the panel edge condition cannot be seen. OVERLAP DETAILING MODEL 5.24 TYPICAL INFILL DETAILS 5.27 REVEAL DETAILING MODEL 5.22 TYPICAL OVERLAP DETAILS 5.25 TYPICAL REVEAL DETAILS 5.23 WARP DETAILING INFILL DETAILING Infill detailing explores the concepts of separateness, compartmentalization, organization, and transition. Infill details are typically clean lines that can organize space or reduce it to a more approachable scale. Infill detailing breaks up planar surfaces with a mixture of textures and sheens; for example, a brass inlay strip in a floor separating honed stone paving from carpet. It can also create a pattern or graphic image in, for example, a terrazzo floor. INFILL DETAILING MODEL 5.26 OVERLAP DETAILING Overlap details can conceal unfinished edge conditions while creating depth in a space. Overlap detailing represents a change of materials in parallel, not perpendicular, planes. Overlapping materials provide sequence and depth and can incorporate transparency. Transitions are highlighted. Warp detailing represents a change of planes, not of materials. Warp details can evoke a sense of weightlessness where the lines between floor, wall, and ceiling no longer exist. Warp detailing often exploits modern materials and fabrication methods; for example, plastics, bent wood forms, or the “fish-scaling” of materials. WARP DETAILING MODEL 5.28 08_9780470889015_ch05.qxd:WILEY 9/19/11 10:18 AM Page 37 CONTRACT DOCUMENTS TYPICAL WARP DETAILS 5.29 ering. This specification type is relatively rare, because designers are most often concerned with a product’s appearance as well as its performance. REFERENCE STANDARD SPECIFICATIONS Reference standard specifications are based on requirements set by an accepted authority. For example, by specifying compliance with ANSI A108, American National Standard Specifications for the Installation of Ceramic Tile, the requirements of the standard are included in the specification by reference. Reference standard specifications tend to be the briefest type of specifications. When referencing a standard, it is important that the specifier understand the standard and verify that all provisions of the standard apply to the project. SPECIFICATION INFORMATION CLASSIFICATION MasterFormat, published by the Construction Specifications Institute (CSI) and Constructions Specifications Canada (CSC), is a list of numbers and titles that classify the materials and requirements of construction and FF&E projects. It is used to organize project specifications and file product information. MasterFormat is composed of 16 divisions, each identified by a five-digit numbering system. The first two digits indicate the division number; the last three denote the section location within the division. D E SI G N BASI CS The topics of Divisions 2 through 16 are included in a project specification only if they are relevant to the project. However, every project specification includes Division 1–General Requirements, which governs the execution of sections in Divisions 2 through 16. Division 1 contains the administrative and procedural requirements pertaining to all the sections of the specification and is the key to administering a construction or FF&E contract. SPECIFICATION FORMATS CSI has established formats for specification information classifications (MasterFormat), sections (SectionFormat), and pages (PageFormat). These three formats provide the basis for a complete, concise, and coordinated project manual in which information can be reliably and easily located. SectionFormat organizes the information presented in each specification section into three parts: Part 1—General: Describes the administrative and procedural requirements specific to the section Part 2—Products: Contains the requirements for the appearance and performance attributes of the items included in the section Part 3—Execution: Describes the preparation for and the construction or installation of items included in the section MASTERFORMAT DIVISIONS 5.30 DIVISION Price and payment procedures, administrative and quality requirements, temporary facilities, product and execution requirements, facility operation and commissioning 2 Site Construction Materials and methods, remediation, and preparation; earthwork, tunneling; foundation and loadbearing elements; utility services, drainage and containment; bases, pavements, etc.; site improvements, planting, restoration and rehabilitation 3 Concrete Materials and methods, forms, accessories, and reinforcement; cast-in-place and precast concrete; cementitious decks and underlayment; grouts; mass concrete; restoration and cleanup 4 Masonry Materials and methods; masonry units, stone, refractories, corrosion-resistant and simulated masonry; masonry assemblies, restoration, and cleaning 5 Metals Materials and methods; structural metal framing, joists, decking, cold-formed metal framing; metal and hydraulic fabrications; railroad track; ornamental metal; expansion control; restoration and cleaning 6 Wood and Plastics Materials and methods; rough and finish carpentry and architectural woodwork; structural plastics and plastic fabrications; restoration and cleaning 7 Thermal and Moisture Protection Materials and methods; dampproofing, waterproofing and thermal protection; shingles, roof tiles, roofing and siding panels, membrane roofing; flashing and sheet metal, roof specialties; fire and smoke protection; joint sealers 8 Doors and Windows Materials and methods; metal doors and frames, wood and plastic doors, and specialty doors; entrances and storefronts; windows and skylights; hardware; glazing and curtain walls 9 Finishes Materials and methods; metal support assemblies; plaster and gypsum board; tile and terrazzo; ceilings, flooring, and wall finishes; acoustical treatment; paints and coatings 10 Specialties Visual display boards, compartments, and cubicles; louvers, vents, grilles, and screens; wall and corner guards; access flooring; pest control; fireplaces and stoves; manufactured exterior specialties, flagpoles 11 Equipment Maintenance, security and vault, teller and service equipment; ecclesiastical, library, theater and stage, and instrumental equipment; registration and checkroom, mercantile, commercial laundry and dry cleaning, vending, and audio-visual equipment; vehicle service, parking control, and loading dock equipment; solid waste handling, water supply and treatment, and fluid waste disposal equipment, and hydraulic gates and valves; detention equipment; food service and residential equipment and unit kitchens; athletic, recreational, and therapeutic equipment, darkroom, laboratory, planetarium, and observatory equipment, office equipment; medical and mortuary equipment; navigation and agricultural equipment; and exhibit equipment 12 Furnishings Fabrics, art, manufactured casework, furnishings and accessories, furniture, multiple seating, systems furniture, interior plants and planters, furniture restoration and repair 13 Special Construction Air-supported structures; building modules; special purpose rooms; sound, vibration, and seismic control; radiation, lightning, and cathodic protection; pre-engineered structures; swimming pool, aquariums, aquatic park, tubs and pools, and ice rinks; kennels and animal shelters; site-constructed incinerators, storage tanks, filters underdrains, digester covers, oxygenation and sludge conditioning systems; hazardous material remediation; measurement, control, recording, and transportation control instrumentation; solar and wind energy equipment; security access and surveillance; building automation and control, detection and alarm, and fire suppression 14 Conveying Systems Dumbwaiters, elevators, escalators and moving walks, and lifts; material handling, hoists and cranes, turntables, and scaffolding; transportation 15 Mechanical Materials and methods; building services, process, and fire protection piping; plumbing fixtures and equipment; heat-generation, refrigeration, HVAC, and air distribution equipment; HVAC instrumentation and controls, testing, adjusting, and balancing 16 Electrical Materials and methods; wiring methods, electrical power, transmission and distribution, and low-voltage distribution; lighting; communications, sound and video CONSTRUCTION SPECIFICATIONS TYPES OF SPECIFICATIONS There are four basic types of specifications: proprietary, descriptive, performance, and reference standard. Most specifications incorporate features from more than one type. For example, a proprietary specification for a particular fabric might also include reference standards for flammability and abrasion resistance. PROPRIETARY SPECIFICATIONS Proprietary specifications require a specific product from a specific manufacturer indicated by a brand name or model number. The specifier has complete control over what will be incorporated in the project when a proprietary specification is used. FF&E specifications are commonly proprietary. For example, “Knoll Group, Studio Line, Barcelona Chair, with black leather upholstery,” is a proprietary specification. DESCRIPTIVE SPECIFICATIONS Descriptive specifications detail the requirements for material properties and workmanship. Manufacturers and products are not named. Descriptive specifications are the most difficult to write, because every aspect of the topic must be considered. For example, an acoustical ceiling tile would be specified by describing the tile material, pattern, finish, color, edge detail, thickness, and size. PERFORMANCE SPECIFICATIONS Performance specifications describe the required results. They describe how a product or material is to perform, not necessarily what it is. The construction contractor or FF&E contractor has a choice of products, materials, and processes that will be used to achieve these results. Performance specifications typically make reference to industry standards. It is helpful to include standard test methods to ensure that performance requirements are met objectively. For example, an acoustical wall panel could be specified by describing its fire-test-performance characteristics, its acoustical properties, and the abrasion resistance of its fabric covContributors: Faith Baum, AIA, IIDA; Faith Baum Architect; Lexington, Massachusetts Jeffrey Meese, AIA; Cambridge, Massachusetts. DESCRIPTION 1 General Requirements 37 08_9780470889015_ch05.qxd:WILEY 38 9/19/11 D E SIG N B A SICS 10:18 AM Page 38 COMPUTING TECHNOLOGIES C O M PU T ING T E CH NOLOGIES COMPUTER-AIDED DESIGN AND BUILDING INFORMATION MODELING The following is an overview of computing technologies that support and enhance the delivery of professional services within the contemporary interior design firm. Topics include not only the recent transition of design software from computer-aided design (CAD) to BIM but also IPD; virtual collaboration tools, including integrated messaging, Web-based meetings, project Web sites, and social media; and emerging technologies such as software as a service (SaaS) and future trends. During the 1990s, computer-aided design tools became commonplace among interior design firms and are still in use today. Software programs such as AutoCAD and MicroStation are used by professional staff to develop two-dimensional (2-D) design drawings and construction documents. Three-dimensional (3-D) models, renderings, and animations, produced using tools such as 3ds Max, form-Z, Rhino, and SketchUp, are part of the typical design and delivery process in many practices. Additional 2D illustration tools, such as Illustrator and Photoshop, are also used to provide visual enhancements to drawings, illustrations, photographs, and presentations. Compared to manual drafting, 2-D CAD software offers significant productivity and quality improvements, making it easier to share and reuse drawing information between different sheets, visually coordinate consultant information (using CAD as a digital light table), share details between multiple projects, reuse the same base building plan for multiple interior design projects, and, in general, reduce much of the redundancy of manual drafting. At the same time, the content of 2-D drawings produced using CAD remains basically unchanged from the 2-D drawings produced using vellum and pencil. BIM SCREEN SHOT 5.31 Building Information Modeling (BIM) enables design professionals to develop more descriptive and better coordinated 3-D models of their projects. A BIM model includes not only the 3-D geometry and surface materials used for rendering and walk-through animations but also the logical relationships between different types of building objects (e.g., the relationship of a door to a wall, a wall to a floor, walls enclosing a space, etc.), as well as customizable object attributes (height, width, type, thickness, manufacturer, fire rating, etc.). Compared to CAD, the digital content of BIM is intelligent and information rich. BIM also provides key coordination benefits. Using BIM software, each 2-D plan, section or elevation drawing in effect becomes a dynamic “view” or “report” of the 3-D building model. As such, 2D drawings produced from BIM models are better coordinated, because they represent the same information using different data filters and views, instead of separate sets of information that must be manually coordinated. Enlarged plan, section, and detail targets that cross-reference multiple 2-D drawings are also maintained automatically by the BIM software. BIM software is also able to measure and report areas, volumes, material quantities, and object attributes more easily than CAD. BIM models that include time elements for scheduling or construction sequencing are often referred to as 4-D BIMs, while those that contain cost information are referred to as 5-D BIMs. INTEGRATED PROJECT DELIVERY A BIM-enabled design and delivery process that fully integrates the work efforts of the owner, designer, consultants, builder, subcontractors, and fabricators is most commonly known as integrated project delivery (IPD) or virtual design and construction (VDC). Such a delivery process is strongly rewarded by close collaboration between the owner, designer, engineers, contractor, subcontractors, and fabricators. IPD is best understood as a process, not a contract. Its delivery methods can complement a number of contractual arrangements, including design-build, construction management at-risk (CM atrisk), design-bid-build with preconstruction services by the builder, as well as the three-way agreement. What is more important than the form of the contract are the trusted relationships, collaborative behavior, and common goals shared by all parties, without which attempts to implement IPD may fail to meet expectations of productivity and quality improvement. A key objective of IPD is to fully integrate the use of BIM data throughout the entire design and delivery process, including procurement, fabrication, assembly, commissioning, occupancy, and future renovation. As part of its IPD framework, the American Institute of Architects (AIA) advocates earlier involvement of consultants and builders, accelerating design decisions as much as possible, and shifting the design team’s surge of work effort much earlier in the process, where design changes are less costly. VIRTUAL COLLABORATION Integrated delivery means not only using BIM software but also making use of virtual collaboration tools. Most interior design projects involve coordinating design information produced by different team members, including core/shell, interiors, heating, ventilating, and air conditioning (HVAC), lighting controls, furniture systems, information technology (IT), security, and so forth. The process of coordination during design and documentation is iterative and often lengthy, and usually means many design review and coordination meetings. 08_9780470889015_ch05.qxd:WILEY 9/19/11 10:18 AM Page 39 COMPUTING TECHNOLOG I E S Increasingly, virtual collaboration tools are allowing design professionals to share and review design data with each other and collaborate on proposed changes without being physically present in the same room. Using such tools adds scheduling and staffing flexibility, avoids wasted time and expense shuttling between meetings, and reduces carbon output associated with unnecessary travel. Virtual meetings are not a complete substitute for face-to-face meetings; the latter remain essential for project kickoffs, relationship building, and critical problem solving. However, effective virtual collaboration can dramatically reduce the number of in-person meetings and increase the overall efficiency of design staff, particularly when design teams are geographically distributed. Virtual collaboration technologies can be organized into four basic categories: 1. 2. 3. 4. Integrated messaging Web-based meetings Project-specific Web sites Social media FUTURE DEVELOPMENTS In the future, interior design firms will be running more of their software applications, not on their personal computers or in-house network servers, but instead on network servers hosted by outside companies and accessed via the Internet. This migration from running software and storing company data on personal computers and private networks to running software and storing company data securely on the Internet reflects a continuing evolution of software as a product to software as a service (SaaS, typically pronounced “sass”). SaaS is a model of software deployment where a provider licenses the use of a computer application to customers as a service accessible via the Internet. The data and information that individuals or companies publish and access are not stored on computers in their home or office, but on the “cloud” of the Internet. The past decade has witnessed an acceleration of computing technologies that help interior design professionals enhance design quality, improve delivery efficiency, and increase the value of their services to owners and users. Indeed, computing technologies remain an essential component of any successful interior design practice. At the same time, technology by itself rarely provides an enduring competitive advantage. Ongoing improvement in technology price and performance continues to lower the barriers to entry for new service providers, both large and small. A perceived differentiator of today, such as BIM-enabled coordination, desktop videoconferencing, or the use of social media, is guaranteed to become a commodity of tomorrow. Most importantly, computing technology must always be effectively married to a firm’s business vision, delivery process, organizational culture, and the unique talents of individual professionals. The ways in which each interior design practice acquires and deploys technology depends on all of these considerations; there is no one-size-fits-all approach. As a firm develops its future implementation plans, therefore, the following characteristics of technology are worth keeping in mind: • Technology is a leveler, allowing small, agile design firms to collaborate virtually and mimic (and in some cases, surpass) the capabilities of large design firms. • Technology is an enabler, facilitating new delivery methods and new types of improved collaboration between owners, designers, engineers, contractors, and fabricators. • Technology is a magnifier, enhancing the productivity and quality of a well-organized practice composed of talented professionals. It can also do the opposite when applied to a disorganized practice that lacks talent. Technology can enhance talent but cannot compensate for its absence. • Technology is a connector, allowing a new generation of design professionals to build virtual design teams and learning communities by using Web-based tools, including social media. Technologies such as e-mail, messaging, videoconferencing, blogging, and project-specific Web sites continue to erase the geographic boundaries of practice. The unwritten future is how computing technologies, both those described in this section and others yet to be invented, will be joined together in surprising new ways. DIGITAL FABRICATION Computer-aided design and manufacturing (CAD/CAM) technologies are changing the roles and responsibilities of design and construction professionals. CAD/CAM and computer numerically controlled (CNC) technologies are widely used in industrial design and manufacturing, and are increasingly being used by architecture firms. D E SI G N BASI CS Digital models facilitate communication between designer, contractor, and client. A fly-through of a master model illustrating the three-dimensional geometry of a building’s forms and spaces allows markups and notes saved for future discussions. Multiple 3D element models describing the details of each part’s shape can be integrated with CNC fabrication instructions, and associated with material and installation specifications, part identifiers, and pricing information. DIGITAL MODELING ENVIRONMENTS Commonly used digital design systems typically make one of the following types of three-dimensional models: • Classical models are simple models that rely on direct application of mathematical equations. • Wireframe models are simple models made from points and lines. • Surface models can show curved surfaces that look good, but without careful construction, they may contain inaccuracies such as unwanted intersections and gaps, and typically lack data needed for CNC machines. • Cross-sectional models slice a digital model into a series of cross sections, which are then cut out using CNC tools. • Solid models have curves and boundary surfaces that are exactly numerically defined. They contain more information, and provide the specific data necessary for working with CNC machines. REVISING MODELS Some modeling systems have to be rebuilt to be revised. Many digital systems do not record the steps taken to produce the model, making it impossible to recover the process. Digital environments with hierarchical-based structures record the steps taken, and list, name, and identify variables. Parametric variation allows the designer to vary certain parameters of an object to generate instances of the design, all derived from the same characteristic shape but varying slightly in dimension or shape. DIGITAL MANUFACTURING PROCESSES Numerical control technology is the automatic operation of machinery from numerically encoded instructions, which are usually derived from a digital design model. Common types of CNC machines include routers, lathes, milling machines, saws, drills, water jets, and laser cutters. CROSS-SECTIONAL MODELS 5.32 Source: Daniel Schodek, Martin Bechthold, Kimo Griggs, Kenneth Martin Kao, and Marco Steinberg, Digital Design and Manufacturing, Figure 15-18, page 307, John Wiley & Sons, 2005 Contributor: Ken Sanders, FAIA, Principal/Managing Director, Gensler, San Francisco. 39 08_9780470889015_ch05.qxd:WILEY 40 9/19/11 D E SIG N B A SICS 10:18 AM Page 40 COMPUTING TECHNOLOGIES CNC MACHINES 5.33 CNC HOT-WIRE FOAM CUTTING TOOL 5.35 Source: Daniel Schodek, Martin Bechthold, Kimo Griggs, Kenneth Martin Kao, and Marco Steinberg, Digital Design and Manufacturing, Figure 110, page 13, John Wiley & Sons, 2005 Some CNC fabrication processes with design applications include: • Solid free-form fabrication, also known as 3-D printing, builds up a model in thin layers and is often used for prototype production. • Reverse engineering involves scanning a physical model to create a digital model that can be revised and modified. • Hot wire cutting is used for architectural models, as well as for insulation, ornamental details, and other building purposes. Source: Daniel Schodek, Martin Bechthold, Kimo Griggs, Kenneth Martin Kao, and Marco Steinberg, Digital Design and Manufacturing, Figure 1424, page 266, John Wiley & Sons, 2005 3-D DIMENSIONAL SCANNING 5.34 Source: Daniel Schodek, Martin Bechthold, Kimo Griggs, Kenneth Martin Kao, and Marco Steinberg, Digital Design and Manufacturing, Figure 1-13, page 15, John Wiley & Sons, 2005 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 41 SECTI O N 2 BUILDING ELEMENTS CHAPTER 6 43 Building Structure and Shell CHAPTER 7 89 Interior Construction CHAPTER 8 283 Equipment and Furnishings CHAPTER 9 326 Interior Project Types 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 42 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 43 BUILDING STRUCTURE AND SHELL 6 SUBSTRUCTURE WALL FOUNDATIONS INTERIOR LOAD-BEARING CMU FOUNDATION WALL 6.1 BASEMENT WALLS Foundation walls are used where basements are not required and where firm soil is adequate to support a limited load. The excavation typically is to below frost depth or as required by the geotechnical engineer. The wall thickness is usually 8 in. (203 mm) but may be thicker to support thicker walls. Minimal amounts of reinforcing steel are required to limit cracking. Reinforcing requirements may increase as the height of the building wall increases. CONCRETE BASEMENT WALLS Concrete basement walls may be either cast in place or precast. Cast-in-place concrete basement walls provide a cost-effective means of supporting a floor and resisting soil pressures, and are used in both commercial and residential construction. Forms are easily placed in the excavation on the footings. Reinforcing steel is placed within the wall formwork. In colder climates, insulation on the inside face of the foundation and under the slab helps to minimize the cold penetration to the interior. Precast concrete basement walls enable basement construction in less time than conventional cast-in-place concrete. Precast concrete construction also permits the use of concrete admixtures that focus on ultimate strength, rather than cure time and temperature. Generally, an isolation joint is provided at the slab-wall interface to allow the slab and grade wall to settle independently. Standard foundation walls may be constructed using concrete, masonry units, or wood. Wood in direct contact with masonry materials should be pressure treated or naturally decay resistant. Lumber and plywood used in treated wood foundations must be grade stamped for foundation use. The U.S. Forest Service provides a list of wood preservative alternatives. Treated wood products used in foundation construction are required to contain more preservatives than treated wood used in fencing, decking, and similar applications. Skin contact and prolonged or frequent inhalation of sawdust when handling or working with any pressure-treated wood product should be avoided. SUBGRADE ENCLOSURES MASONRY BASEMENT WALLS Source: Based on NCMA Annotated Design and Construction Details for Concrete Masonry, Figure 3E.8. Courtesy of National Concrete Masonry Association. INTERIOR NON-LOAD-BEARING WALL 6.2 Masonry walls have long served as foundations for structures. Today, most masonry basement walls consist of a single wythe of solid or hollow concrete masonry units, depending on the required bearing capacity. The walls are reinforced as necessary to resist lateral loads. Basement walls should protect against heat and cold, insect infestation (particularly termites), fire, and penetration of water and soil gases. Architectural masonry units may be used to improve the appearance of the wall. Masonry units with architectural finishes facing the interior can be used for economical construction of finished basement space. Masonry easily accommodates any floor plan, and returns and corners increase the structural performance of the wall for lateral load resistance. Source: Based on NCMA Annotated Design and Construction Details for Concrete Masonry, Figure 8B.2. Courtesy of National Concrete Masonry Association. 09_9780470889015_ch06.qxd:WILEY 44 9/19/11 10:24 AM Page 44 BUILD ING ST RU CT URE AND SHELL CONCRETE BASEMENT WALLS 6.3 SUBSTRUCTURE TYPICAL MASONRY BASEMENT WALL 6.4 BASEMENT THERMAL INSULATION Insulation requirements are proportional to heating loads. The foundation is often underinsulated and can be a major source of heat loss. The desirable insulation level depends on the use of the basement space, basement temperature, and insulation levels in the rest of the building. Exterior insulation keeps the wall warm and eliminates condensation and thermal bridges. As seasonal basement temperature decreases, losses to it from the superstructure increase, and basement ceiling R-values should increase. SLABS ON GRADE Factors to consider in the design and construction of all concrete slabs on grade include the intended use of the slab or slab section, the condition and preparation of a uniform subgrade, the quality of the concrete, the adequacy of structural capacity, the type and spacing of joints, the finishing, the curing, and the application of special surfaces. Source: Based on ACI 332, Requirements for Residential Concrete Construction and Commentary, Figure R7.1. Reprinted with permission of the American Concrete Institute. Wear resistance is directly related to the condition of the top portion of the concrete slab. Surface hardness and abrasion resistance may be provided by special additives or hardeners to the surface. The quality of the overall concrete slab will be enhanced by the proper water-to-cement ratio, reasonable slump limits, and well-graded aggregates with the maximum size of the coarse aggregate as large as placing will permit. Reinforcement in concrete slabs is unnecessary where frequent joint spacings are used. Where less frequent spacings are used, reinforcement is placed in the slab, at or above mid-depth (generally one-third down from the top surface), to act as crack control. Common contraction joint spacing is 15 to 25 ft (4.6 to 7.2 m), depending on the thickness of the slab and the construction type. Strip placement, rather than checkerboard placement of slabs, is recommended for large areas. CONCRETE SLAB JOINTS Construction joints facilitate the concrete pouring process. Expansion and contraction joints are installed to accommodate building movement. • Construction joints between two successive placements of concrete are often keyed or doweled to provide lateral stability across the joint. • Expansion joints between two parts of a building or structure permit thermal or moisture expansion to occur without damage to either part. Expansion joints also serve as isolation joints and control joints. 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 45 SUPERSTRUCTURE • Isolation joints separate two sections of a structure to allow differential movement or settlement between the slab and fixed parts of the building such as columns, walls, and machinery bases. • Control joints are continuous grooves or separations formed, sawed, or tooled in concrete to form a plane of weakness and thus regulate the location and amount of cracking resulting from drying shrinkage or thermal stresses. • Contraction joints between two parts of a structure are designed to compensate for the contraction of either part. BUILDING ST RU CT U R E AN D SH E LL CONCRETE SLAB FINISHES Concrete floor slabs are monolithically finished as a general procedure by floating and troweling to a smooth and dense top finish. ACI 302 provides specific guidance for appropriate finishing procedures to control the achievable floor flatness. ACI 302, ACI 360, and ACI 117 provide guidance for flatness selection and the techniques by which flatness and levelness are produced and measured. Floor finish tolerance is measured by placing a freestanding 10-ft (3 m) straightedge on the slab surface or by the F-Number system, which is preferable. Special finishes are available to improve appearance as well as surface properties. These include sprinkled (shake) finishes or high-strength toppings, either as monolithic or as separate twostage floor surfaces. SUPERSTRUCTURE The structural system of a building is designed and constructed to support the loads applied to the building and to transmit them safely to the ground without damage to the building. Some structural systems are based on a single material, such as heavy timber structures. Others combine more than one material. A building may have more than one structural system. What appears to be a structural material may actually be only an exterior facing material. HORIZONTAL SEISMIC LOAD 6.5 Precast, prestressed concrete structural elements include: • Solid flat slab: plank used for short spans and uniformly distributed loads • Hollow-core slab: plank with hollow cores that reduce weight; used for uniformly distributed loads over medium to long spans • Single and double tees: T-shaped plank with a single or double stem and broad, flat slab • Ledger beam: beam with projecting ledges to support the ends of joists or slabs; L or inverted T shapes Structural elements visible within interior spaces include supports such as columns, horizontal structural elements such as beams and trusses as well as horizontal floor and ceiling planes, and loadbearing interior walls. When working with structural elements, it is important to remember that changes in one part of the structure result in changes in loads carried by other parts. Respect the structural properties of the materials involved, and use caution tempered by understanding. It is wise to avoid major structural changes where possible; they are expensive and may be complex. Precast concrete wall panels are used for bearing walls that support site-cast concrete floors or steel floor and roof systems. They are usually 8 ft (2.4 m) wide but are available up to 12 ft (3.7 m) wide. Precast concrete columns are commonly produced to support these approximate areas: SEISMIC CONSIDERATIONS An earthquake produces vibrations in the earth’s crust by the sudden movements of plates along fault lines. These movements spread as three-dimensional waves. The structural system of a building must be designed to withstand seismic forces from any direction. Buildings are already designed to carry substantial gravity-related vertical loads. Therefore, added horizontal loads are considered the most critical in seismic design. A load path is the path seismic forces take from the roof to the foundation of a structure. Typically, the load travels from the diaphragms through connections to the vertical elements and on to the foundation by way of additional connections. This path should be direct and uninterrupted. Seismic design begins with, and codes require, the establishment of a continuous load path. SUPERSTRUCTURE FRAMING CONCRETE FRAMING Concrete is either cast in place, where it will be used by a concrete mixer or agitator truck, or precast off-site under factory-controlled conditions. Concrete used for construction is usually reinforced with steel reinforcing bars or with welded wire fabric. PRECAST CONCRETE FRAME Precast concrete frame systems are ideal for highly repetitive structural frames such as parking garages and multiple residences (hotels, apartments, dormitories). Precast concrete members can be precast structural concrete or precast architectural concrete in exposed locations. Using shear walls in both directions is the most common method to resist lateral loads. Stair and elevator cores and dwelling unit separations may also serve as shear walls. Contributor: Richard Eisner, FAIA, Governor’s Office of Emergency Services, Oakland, California. Precast concrete structural elements are cast and steam-cured off-site, transported to the site, and set in place with cranes. They may be reinforced or prestressed for extra strength or reduced thickness. • A 10 by 10 in. (254 by 254 mm) column supports 2,000 sq ft (186 sq m). • A 12 by 12 in. (305 by 305 mm) column supports 2,750 sq ft (255 sq m). • A 16 by 16 in. (406 by 406 mm) column supports 4,500 sq ft (418 sq m). Precast concrete components are usually pretensioned. Pretensioning is a method of prestressing concrete in which steel tendons are stretched prior to placement of the concrete and maintained in tension until the concrete is cured. The external tension on the tendons is then released to compress the concrete. The example in Figure 6.6 employs prestressed columns, inverted T-girders, ledger girders, and double-T joists, all of the same length and design. Once the floor and roof Ts are set, the surface is covered with a thin concrete topping that provides the finished, weather-exposed surface and a horizontal structural diaphragm. The precast components are fabricated off-site and lifted into place by crane. Various finished surfaces are possible, and the unity of materials presents an opportunity for natural visible integration of elements. Thin brick or tile can also be used as a surface material. Double-T joists are generally 8 or 12 ft (2.4 or 3.7 m) wide, at a depth of 18 to 36 in. (457 to 914 mm), depending on the spanning requirements. Spans of 60 ft (18.3 m) are considered maximum, due to the constraints of shipping and lifting the pieces, but longer spans and deeper sections are possible. 45 09_9780470889015_ch06.qxd:WILEY 46 9/19/11 10:24 AM Page 46 BUILD ING ST RU CT URE AND SHELL PRECAST CONCRETE FRAME 6.6 SUPERSTRUCTURE FLAT-PLATE AND POSTTENSIONED CONCRETE Flat-plate concrete construction combines cast-in-place concrete columns with two-way concrete slab plates of uniform thickness. Two-way flat-plate concrete floors are among the simplest concrete structures for reinforcing, formwork, and detailing. Posttensioning is a method of reinforcing concrete by stretching steel reinforcing tendons after placement and curing of the concrete structure. This prestressing reduces or eliminates tensile stresses on the concrete under use loading and strengthens the slab without increasing its thickness or adding the dead loads introduced by additional steel reinforcing rods. Posttensioning is useful when slab thickness is important to economical or functional design aspects or when concentrated live loads are high and the building height must be kept to a minimum. It is also effective when project conditions require minimal floor-to-floor heights but maximum ceiling heights with generous space above the ceilings. Posttensioned concrete construction is virtually identical to flatplate concrete construction. The major difference lies in the thickness of the concrete slab, which is slightly reduced with posttensioning. Flat-plate concrete construction permits more stories to be fitted into a given building height than any other system. This is because its floor structure has minimum thickness, especially when posttensioned. Flat-plate construction is typically used for low- to medium-rise construction because of the costs and difficulties associated with placement of materials and labor in higher buildings. It is especially applicable to apartments, hotels, and dormitories, in which no suspended ceiling is required. Story height can be minimized in these applications by using the undersides of the slabs as finished ceiling. Cast-in-place concrete slabs are classified by whether they have steel reinforcing running in one, two, or three directions. The reinforcing pattern affects how the slabs carry the stresses created by loads to other structural members or the ground. Slabs are usually cast with their supporting beams. Flat-plate construction usually has a central core for vertical circulation and services. The central core also permits consolidation of vertical service risers, increasing fire protection by reducing or eliminating through-floor penetrations in office areas. A centralized core permits relatively uniform, short horizontal runs for power, plumbing, lighting, and mechanical systems. Workstations in unpartitioned interior offices can be serviced unobtrusively by ceiling-height power and communications poles, in furred-out areas around columns, and in corridor partition walls. Office workstations require daylight exposure and views. Because the central core is farthest from perimeter zones, usable floor area in the perimeter can be maximized. On constrained urban sites, the central core may be moved against an unfenestrated wall and still retain this advantage. LEGEND A B C D E F G Concrete topping as floor finish Prestressed, precast concrete double-T Fluorescent light fixtures attached to structure Prestressed, precast concrete columns and spandrel beams Cast-in-place concrete vertical circulation Slab on grade, with cast-in-place concrete piles Elevator equipment for hydraulic elevator Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 47 SUPERSTRUCTURE FLAT PLATE AND POSTTENSIONED CONCRETE 6.7 BUILDING ST RU CT U R E AN D SH E LL WOOD FRAMING The superstructure of a light-frame building encloses interior spaces and carries loads to the ground. Many wood structures originally designed as family homes find new lives as commercial buildings. Codes for residential and commercial buildings have different requirements that must be considered. Light wood frame construction consists of dimensional lumber that is uniformly cut. Heavy-timber construction uses beams cut from large trees. Spaced beams made with blocking and open spaces to reduce weight and laminated beams made from pieces of wood glued together are also used in wood frame construction. Lightgauge steel framing is often used in building interiors with existing wood framing. WOOD TRUSSES Prefabricated floor and roof trusses are built at the factory to engineering specifications. Laminated wood trusses consist of smaller pieces of wood glued together into large trusses. Open-web wood trusses allow threading of wiring, piping, and ductwork without onsite drilling or cutting. Roof trusses come in a variety of shapes and sizes. The top chords serve as roof rafters, and the bottom chords act as ceiling joists. WOOD COLUMNS Wood columns may be solid wood or built out of wood pieces either solidly glue laminated or mechanically fastened together. Spaced wood columns are made of multiple structural members with blocking and spaces inside. WESTERN OR PLATFORM FRAMING The most common type of wood framing is western or platform framing. Before any of the superstructure is erected, the first-floor framing and subflooring is put down, making a platform on which the walls and partitions can be assembled and tilted into place. Because floor framing and wall frames do not interlock, adequate sheathing must act as bracing and provide the necessary lateral resistance. Where required for additional stiffness or bracing, metal strapping or 1 4s may be let into the outer face of studs at 45° angles, secured at top and bottom and to studs. The process is repeated for each story of the building. Roof framing may be level, I-joist, or trusses. Floor joists may be any of the following types of beams: heavy timber, laminated veneer lumber (LVL), parallel strand lumber (PSL), glue laminated, built up, flitch, or box. Platform framing has essentially replaced balloon framing. Balloon framing with studs continuous from wood sill to top plate is rarely used, except in special locations, such as in two-story spaces, at parapets, and in similar situations where a structural cantilever of the wall is required. LEGEND A B C Built-up roofing or single-ply membrane on rigid insulation Concrete slab with reinforcing steel bars Ducts with diffusers, suspended from structure in ceiling plenum D Fluorescent light fixture in ceiling E Suspended acoustical tile ceiling F Resilient floor G Operable partitions H Metal stud and gypsum wallboard assembly I Window assembly J Concrete K Brick and concrete masonry with rigid insulation L Slab on grade and concrete foundation M Vapor barrier under slab N Waterproofing and protective board at foundation Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). 47 09_9780470889015_ch06.qxd:WILEY 48 9/19/11 10:24 AM Page 48 BUILD ING ST RU CT URE AND SHELL PLATFORM FRAMING 6.8 Contributor: Timothy B. McDonald, Washington, DC. SUPERSTRUCTURE 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 49 SUPERSTRUCTURE PLATFORM FRAMING—SECTION 6.9 BEAMS 6.12 BUILDING ST RU CT U R E AN D SH E LL JOISTS BEARING ON RIBBON 6.14 HEAVY-TIMBER CONSTRUCTION Heavy-timber construction is characterized by large, exposed timber columns, beams, and other structural members, joined together by traditional pegged mortise and tenon or similar joints. Heavy timber uses rectangular solid wood framing members that are nominally a minimum of 5 in. (127 mm) in both dimensions. Heavytimber fabricated timber frame modules are called bents. Bents run perpendicular to the ridge, and include the primary columns, beams, girders, rafters, and knee braces. Bents are typically spaced 10 to 16 ft (3 to 4.9 m) on center. WOOD JOISTS SUPPORTED ON STEEL BEAM 6.10 Heavy-timber structures are typically enclosed with stressed-skin insulated panels, leaving the frame totally exposed on the interior. Heavy-timber construction is being updated with modern materials such as glue-laminated members and proprietary concealed metal connections. BALLOON FRAMING BALLOON FRAMING 6.13 GLUE-LAMINATED CONSTRUCTION The term glue laminated (glulam) refers to an engineered, stressrated product made of wood laminations bonded with adhesives, with the grain approximately parallel lengthwise. Laminated pieces can be end-joined to form any length, be glued edge to edge to make wider pieces, or be composed of bent pieces curved during the laminating process. STANDARD WIDTHS 6.15 NOMINAL WIDTH WOOD JOISTS SUPPORTED ON WOOD BEAM 6.11 NET FINISHED WIDTH 3 (76) 2-1/8 (54) 4 (102) 3-1/8 (3 for southern pine) (79, 76) 6 (152) 5-1/8 (5 for southern pine) (130, 127) 8 (203) 6-3/4 (171) 10 (254) 8-3/4 (8-1/2 for southern pine) (222, 216) 12 (305) 10-3/4 (10-1/2 for southern pine) (273, 267) 14 (356) 12-1/4 (309) 16 (406) 14-1/4 (362) FIRE SAFETY Similar in nature to those of heavy timber, the self-insulating qualities of glue-laminated construction cause the members to burn slowly. Good structural details, elimination of concealed spaces, and use of vertical fireblocking contribute to its fire resistance and ability to retain its strength longer than unprotected metals. Therefore, building codes generally classify glue-laminated construction as heavy-timber construction if certain minimum dimensional requirements are met. Codes also allow for calculation of one-hour fire ratings for exposed glue-laminated members. Contributors: Timothy B. McDonald, Washington, DC. Joseph A. Wilkes, Wilkes and Faulkner, Washington, DC. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. 49 09_9780470889015_ch06.qxd:WILEY 50 9/19/11 10:24 AM Page 50 BUILD ING ST RU CT URE AND SHELL POST AND BEAM CONSTRUCTION Although used historically for larger buildings, post and beam construction is now generally confined to buildings of three stories or fewer. Its main advantages are simplicity of elements and details, combined with the potential for visual integration and bold structural and architectural forms. SUPERSTRUCTURE LAMINATED WOOD POST AND BEAM 6.16 Structure and interior are unified in post and beam construction. Because the structural elements in this system are exposed to view, as are portions of the mechanical system, care is required in the visual integration of these components and in the design and appearance of hardware used to join the wood members. Certain parts of the mechanical system can be concealed within interior partitions and exterior walls. The sizing of structural members and joinery details may be influenced more by considerations of visual proportion and appearance than strictly by the loading and stress conditions involved. LEGEND A B Rigid conduits run through decking Roof deck covered with roofing felt moisture barrier; rigid insulation board between sleepers. Standing seam metal roof over sleepers C Plywood sheathing and wood roof, laminated tongue-andgroove decking, nominally 2-1/4 in. (57) thick, laid over the beams D Air supply and return ducts E Lighting fixtures F Window assembly G Wood siding H Heavy glue-laminated wood beams I Carpeting J Exposed wood frame and plywood sheathing K Wood stud framing L Drywall M Clay tile flooring N Slab on grade and concrete foundation O Vapor barrier under slab NOTES 6.16a. The underside of the laminated tongue-and-groove decking is exposed to interior view and should be specified for appearance grade. b. A vapor barrier is placed toward the occupied side, and the voids are filled with batt or rigid insulation. c. The exterior is sheathed in plywood and finished with diagonal wood siding. d. Kitchens, lavatories, and other areas requiring both odor removal equipment and greater amounts of fresh air are separated by walls and covered by suspended or furred ceilings. Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 51 SUPERSTRUCTURE POST AND BEAM CONNECTIONS 6.17 BUILDING ST RU CT U R E AN D SH E LL MILL CONSTRUCTION Mill construction uses a combination of fire-resistant brick walls with heavy-timber interior construction. It is characterized by large open floor spaces and daylight streaming through large windows. Although this type of construction is rarely used today, many of these buildings still stand, and have been converted into office spaces, housing and studios for artists, and museums. SECTION THROUGH JOIST BEARING 6.20 STEEL FRAMING Iron and steel, and their alloys, are usually the most cost-effective metal choices for structural applications. Steel is a ferrous metal. Nonferrous metals contain little or no iron, generally have good corrosion resistance, and are nonmagnetic. Nonferrous metals include copper and aluminum. Desirable properties of different metals can often be combined by mixing metals together to form alloys. METALS 6.19 FERROUS (CONTAIN IRON) NONFERROUS (CONTAIN LITTLE OR NO IRON) Steel Copper Stainless steel Aluminum Iron Tin SECTION THROUGH STEEL JOIST 6.21 Magnesium Bronze and brass Lead Zinc Titanium TYPES OF STEEL Steel comprises the various alloys of iron and carbon. More than 90% of the steel manufactured into finished products is carbon steel. SPACED BEAM BEARING ON INTERIOR COLUMN 6.18 • Carbon steel: a higher carbon content increases metal strength and hardness but reduces its ductility and weldability. Reasonably strong but poor resistance to corrosion. Used in structural shapes such as welded fabrications or castings, metal studs and joists, fasteners, wall grilles, and ceiling suspension systems. • Galvanized steel: application of zinc to the surface of carbon steel or steel alloys to prevent corrosion; either hot dipped or electroplated. • High-strength, low-alloy (HSLA) steels: better corrosion resistance than carbon steels; chosen when weight is a consideration and higher strength is specified. The most commonly used framing systems for steel construction include open-web steel joists, rigid frames, framed tubes, braced cores, space frames, and moment-resisting frames. OPEN-WEB STEEL JOISTS Steel construction with open-web joists and bearing walls yields buildings that have relatively large interior clear spans and flexible interior layouts. The open webbing of the joist provides a lightweight structure that is easily penetrated by mechanical systems. The bottom chords of the joists are used for suspension of interior finishes, lighting fixtures, and air diffusers in finished areas, although they may be left uncovered. Open-web steel joists are usually covered by 2-1/2 to 3 in. (64 to 76 mm) of concrete on steel decking. Concrete thickness may be increased to accommodate electrical conduit or electrical/communications raceways. Precast concrete, gypsum planks, or plywood can also be used for the floor system. Ceiling supports can be suspended from or mounted directly to the bottom chords of joists, although suspended systems are recommended because of dimensional variations in actual joist depths. Contributor: Timothy B. McDonald, Washington, DC. FABRICATED FIREPROOFED STEEL COLUMNS Fabricated fireproofed steel columns (lally columns) are structural units that consist of load-bearing steel columns filled with concrete. This creates a column with increased load-bearing capacity in a space no larger than a standard column. Lally columns have fire-resistant characteristics when a layer of fireproofing material encases the structural column. Fire ratings typically range from two to four hours. 51 09_9780470889015_ch06.qxd:WILEY 52 9/19/11 10:24 AM Page 52 BUILD ING ST RU CT URE AND SHELL STEEL FRAME WITH CURTAIN WALL Steel frame and curtain wall construction allows for off-site fabrication of frame and envelope components, easy shipping to the site, and rapid assembly at the site. The steel and concrete in the floors are designed to act as a composite diaphragm, providing a thin, lightweight structural element with or without an access floor. The access floor is advantageous in office environments that need especially flexible interior layouts. This system keeps all wires and cables in the space below the finish floor (generally not less than 4 in. [102 mm] deep) and out of wall cavities. Although access floors may add to overall floor-to-floor heights, the access floor conceals the most visually obtrusive distribution elements. SUPERSTRUCTURE STEEL FRAME WITH CURTAIN WALL 6.22 The envelope is structurally independent of the steel frame, providing flexibility in weight, size, and configuration of the envelope system. Curtain wall units are preassembled at the factory. Mechanical systems, hidden in floor or ceiling plenums or both, can be accessed through removable panels in ceiling or floor systems. A suspended ceiling provides space for the distribution of internal services, but it tends to be used principally for overhead lighting and ductwork. RIGID FRAMES Rigid frame construction combines columns and a beam or girder welded together to make a rigid connection. Such a frame can carry vertical loads and resist horizontal forces, either wind or seismic. Rigid frame buildings are usually single story. The roofs are generally sloped, usually at least 1 in 12. Because they span fairly long distances relatively cheaply—widths range between 30 and 130 ft (9.1 and 39.6 m)—rigid frame structures are used for recreational buildings; warehouses; light industrial buildings; and commercial buildings, such as supermarkets, automobile dealer showrooms, and garages. Bay sizes are usually 20 to 24 ft (6 to 7.3 m) but may be extended to 30 ft (9.1 m). The roof profile is most often configured as a symmetrical gable, but such a profile is not a structural necessity. Some manufacturers offer precast concrete and masonry siding. Pre-engineered buildings most often use rigid frames for roof and wall supports. RIGID STEEL FRAME 6.23 LEGEND A B C D E F G H Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). Steel decking welded to frame Built-up roofing or single-ply membrane on rigid insulation Suspended acoustical tile Ducts with diffusers, either suspended from structure in ceiling plenum or placed in floor plenum beneath access floor Curtain wall units Steel with welded and bolted connections Fluorescent light fixture in ceiling Electrical wires and cables placed in concrete floor I J K L M N O P Insulated spandrel panels Gypsum wallboard Systems furniture Carpeted access floor system Steel decking welded to primary frame members, with cast-in-place concrete topping Waterproofing and protective board with foundation drain Slab on grade with concrete foundation Vapor barrier under slab 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 53 SUPERSTRUCTURE FRAMED STEEL TUBE In the framed tube system, structural steel members form the load-bearing exterior perimeter wall; this wall is designed so the entire building becomes, in effect, a structural steel tube. BUILDING ST RU CT U R E AN D SH E LL SPACE FRAME 6.26 The framed tube system is most economical for very tall buildings. The World Trade Center towers in New York were framed tube construction. The Sears Tower in Chicago is the most conspicuous existing example of this construction system. Systems like that of the Sears Tower, a combination of nine framed tubes in a 3 3 array, are sometimes called bundled tubes. FRAMED STEEL TUBE 6.24 BRACED CORE In the braced core system, walls around elevator shafts and stairwells are designed to act as vertical trusses that cantilever up from the foundation. The chords of each truss are building columns; the floor beams act as ties. Diagonals placed in a K-pattern (occasionally in an X-pattern) complete the truss. Braced core systems can be used efficiently in single-story buildings as well as in buildings over 50 stories. Braced frames are cost effective, but disrupt the floor plan if not carefully located around typical core elements such as stairs, shafts, and toilet rooms. BRACED CORE 6.25 SPACE FRAMES A space frame is a three-dimensional truss with linear members that form a series of triangulated polyhedrons. It can be seen as a plane of constant depth that can sustain fairly long spans and varied spatial configurations. The prime attributes of space frame structural systems are their light weight; their inherent rigidity; their wide variety of form, size, and span; and their compatible interaction with other building support systems, primarily HVAC. Metal space frames are classified as noncombustible construction and can usually be exposed when 20 ft (6 m) above the floor. However, an automatic fire-extinguishing system or a fire-rated ceiling may be required. LEGEND A B C D E Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). Built-up roofing and rigid insulation Space frame and metal deck Ducts suspended from hubs of the frame Light fixtures Glass block panel F G H I J Concrete masonry unit (CMU) bearing wall Brick veneer and rigid insulation Wood flooring Slab on grade and concrete foundation Vapor barrier 53 09_9780470889015_ch06.qxd:WILEY 54 9/19/11 10:24 AM Page 54 BUILD ING ST RU CT URE AND SHELL SPACE FRAME SUPPORT TYPES 6.27 SUPERSTRUCTURE LIGHTWEIGHT STEEL FRAME AND BRICK VENEER 6.28 LIGHTWEIGHT STEEL FRAMING Lightweight steel frame bearing wall construction is often used in low-rise commercial and residential buildings. Speed of construction, noncombustibility, and relative light weight are key advantages of this system. The space between studs eases insulation and accommodates piping and electrical distribution. The lightweight cold-formed steel members are load bearing, and beams, columns, channels, headers, and other elements can be built up from standard steel shapes and sections. The frame’s rigidity depends on cross-bracing, the distance from exterior corner to exterior corner, and the type and layout of fasteners used. Sheathing both sides of the frame also provides some lateral stability. The advantages of cold-formed steel framing include its light weight, dimensional stability, speed and ease of assembly, resistance to moisture and decay, and, in some cases, readier availability than wood framing members. Also, steel framing members are frequently made from recycled scrap and can be endlessly recycled. Prepunched holes in the studs provide easy routing of plumbing and electrical lines. Most codes require the use of electrical conduit or sheathing of the prepunched stud opening to avoid stripping the insulation as wires are drawn through. Interior gypsum board applied to steel studs, along with exterior sheathing, provides additional lateral bracing. LEGEND A B C D E F G H Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). Ridge flashing Shingles and roofing felt Metal roof frame (C-stud brace, -rafter, -channel, -joist) Ducts with diffusers Suspended acoustical tile Gypsum board Brick veneer Window assembly I J K L M N O P Carpet Ceramic floor tile Batt insulation Metal floor frame (C-joist), steel deck, and concrete topping C-stud assembly, wiring threaded through wall assembly Resilient floor tile Dampproofing Slab on grade with concrete foundation 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 55 SUPERSTRUCTURE STAGGERED STEEL TRUSS Staggered truss construction is most often used for double-loaded residential-type occupancies, including hotels, high-rise apartments, nursing homes, and hospitals. This system is best suited to multiunit residential or hotel buildings of 7 to 30 stories. Such building types usually have highly repetitive floor plans and can benefit from systems that integrate objectives regarding structure, interior unit separations, fire compartmentalization, and acoustical privacy. The system easily allows for long structural bays, permitting a high degree of flexibility in unit interiors. The ground floor is free of trusses and interior columns and thus is suitable for parking or retail commercial use. The system’s light weight reduces foundation size. BUILDING ST RU CT U R E AN D SH E LL STAGGERED STEEL TRUSS 6.29 Because the trusses extend from floor to ceiling, with openings for corridors and elevator doors only, horizontal running of pipes, wiring, and ductwork can be difficult. For this reason, separate unit-by-unit heating and air-conditioning systems are often preferable. Utilities are typically fed upward through chases and risers on outer walls, with service or supply units placed to either side on each floor; end wall stair enclosures are also used for this purpose. Most sprinkler systems are laid out in this fashion as well. The smooth surface of concrete deck planks can provide interior ceiling finishes, if desired. LEGEND A B C D E F G Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). Rigid insulation under single-ply roofing and ballast Ducts with diffusers, and sprinkler system; underside of concrete planks either painted or covered with acoustical ceiling tile Precast hollow-core concrete plank deck Staggered story-high steel trusses Tile Gypsum board Window assembly H I J K L Precast shear panels Steel columns Conduit fed through vertical chases in outer walls Joints at floor planks grouted, tops carpeted Precast exterior wall panels that support floor slabs on both top and bottom chords M Slab on grade with concrete foundation N Vapor barrier with waterproofing with protective board O Precast stiffener beams 55 09_9780470889015_ch06.qxd:WILEY 56 9/19/11 10:24 AM Page 56 BUILD ING ST RU CT URE AND SHELL MASONRY STRUCTURES Masonry construction is composed of building units of natural or manufactured products usually held together with mortar. Masonry bearing walls are usually one-story structures. Roof spans up to 60 ft (18.3 m) can generally be accommodated. SUPERSTRUCTURE STEEL BAR JOIST WITH BEARING WALL 6.30 Types of masonry building units include: • • • • Concrete masonry units (CMUs) Brick Glass unit masonry Stone and cast stone Masonry units can be assembled into solid walls, cavity walls, or veneered walls. They may be unreinforced or reinforced with metal wall ties or steel reinforcing bars inside grout-filled cavities and joints. Masonry walls are constructed of either solid or hollow masonry units, with joints filled with mortar. Typically, they are constructed in parallel sets to support steel, wood, or concrete spanning systems. It is common for masonry walls to be spanned by open-web steel joists, timber or steel beams, or concrete slabs. Masonry materials expand and contract with changes in temperature and moisture content. Clay masonry units absorb water and expand. CMUs shrink as they dry after manufacture. Movement joints are designed to control these changes. Movement joints are located each 100 to 125 ft (30.5 to 38.1 m) along unbroken lengths of masonry walls. They are also placed at changes in wall height or thickness; at columns, pilasters, and wall intersections; and near corners. They are additionally found on both sides of openings greater than 6 ft (1.8 m) wide, and on one side of openings less than 6 ft. Masonry bearing or shear walls typically have a minimum thickness of 8 in. (203 mm). With reinforcing, this can be reduced to 6 in. (152 mm). Solid 6-in. masonry walls in single-story buildings are limited to 9 ft (2.7 m) in height. In many applications, single-wythe walls are reinforced. Nonreinforced single-wythe walls are used in interior construction where no loads, including lateral loads, or other forces are anticipated. MASONRY BEARING WALL WITH STEEL BAR JOIST Masonry bearing walls and metal joist roofs are among the simplest and easiest to design and build. The height to which masonry bearing walls can be built without resorting to lateral bracing is limited, so they are used most frequently in one-story structures. Bearing wall and bar joist roof building systems employ masonry walls bearing on a turndown slab on grade or conventional spread footings. The walls support a roof structure of open-web steel bar joists, through which mechanical distribution systems are threaded. Roof spans up to 60 ft (18 m) can generally be accommodated. The spacing and depth of joists is related to the spanning capability of the roof decking material and the requirements for loads on the roof structure. Steel open-web joist and bearing wall construction yields buildings that have relatively large interior clear spans and flexible interior layouts. The open webbing of the joists provides a lightweight structure that is easily penetrated by mechanical systems. The bottom chords of the joists are used for suspension of interior finishes, lighting fixtures, and air diffusers in finished areas, although they may be left uncovered. Suspended interior ceilings are nearly always preferred to directly attached interior ceilings. Finished ceilings attached directly to the bottom joist chord are not only difficult to alter but must be designed to accommodate the high degree of deflection the roof assembly will experience. If ductwork is to be housed within the depth of the joist, headers or branches must be fed through the joist webs, perpendicular to the spanning direction. MASONRY BEARING WALL AND METAL JOIST ROOF Masonry bearing walls and metal joist roofs are among the simplest and easiest to design and build. The relatively low cost of the system makes it attractive for speculative projects, as does the fact that contractors find this construction method familiar and easy to erect. Retail commercial facilities often require flexibility in lighting, partitioning, and mechanical systems and large expanses of columnContributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland, based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). LEGEND A B C D E F Rooftop mechanical unit Built-up roofing and rigid insulation Steel decking and open-web steel joists Exterior insulation and finish system (EIFS) Suspended acoustical tile, sprinkler system suspended from structure in ceiling plenum Fluorescent light fixture in ceiling G H I J K L M N Ductwork Concrete masonry bearing wall and concrete footing Glazed interior face on concrete masonry unit (CMU) Resilient tile Canopy assembly Vapor barrier and dampproofing Slab on grade Window assembly and wall-free space; the envelope and structural systems chosen often reflect these demands. related to the spanning capability of the roof decking material and the requirements for loads on the roof structure. The height to which masonry bearing walls can be built without resorting to lateral bracing is limited, so they are used most frequently in one-story structures. Roof spans up to 60 ft (18.3 m) can generally be accommodated. The spacing and depth of joists is Suspended interior ceilings are nearly always preferred to directly attached interior ceilings. Finished ceilings attached directly to the bottom joist chord are not only difficult to alter but must be designed to accommodate the high degree of deflection the roof assembly will experience. 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 57 FL O O R CO NST RUCTION ASSEMBLIES BUILDING ST RU CT U R E AN D SH E LL F L O O R CO NST RU CT IO N ASSEMBLIES WOOD FLOOR FRAMING WOOD ROOF TRUSS AND WOOD FLOOR TRUSS 6.31 In a standard wood framing system with prefabricated roof and floor trusses and exterior sheathing, the trusses are built at the factory to engineering specifications. Open-web trusses allow threading of wiring, piping, and ductwork without on-site drilling or cutting, thus greatly speeding and easing the installation of heating, plumbing, and electrical systems. Openweb wood trusses permit longer clear spans than conventional timber framing, leaving greater flexibility for the location of interior partition walls that need not be load bearing. Prefabricated roof and floor trusses eliminate much field labor, thus speeding up on-site construction; help ensure dimensional stability; and may eliminate the need for intermediate load-bearing partitions. Longer clear spans are possible with floor trusses than with generally available dimension lumber. The smaller wood components used in prefabricated trusses are more readily available from sustainably grown sources, as opposed to the older-growth trees harvested for larger standard lumber sections. LEGEND A B C D E F G Shingles and roofing felt with metal flashing Wood roof truss and plywood sheathing Acoustical tile Wood frame Batt insulation Gypsum board Wood floor truss and plywood subfloor H I J K Ducts and diffusers Lapped wood siding Window assembly Slab on grade, concrete masonry foundation wall, and concrete footing L Carpet M Below-slab perimeter ducts 57 09_9780470889015_ch06.qxd:WILEY 58 9/19/11 10:24 AM Page 58 BUILD ING ST RU CT URE AND SHELL FLOOR CONSTRUCTION ASSEMBLIES FLOOR FRAMING WOOD BEAMS 6.34 WOOD FLOOR FRAMING MEMBERS 6.32 FRAMING MEMBER TYPE DESCRIPTION COMPOSITION [NOMINAL DIMENSIONS] Dimension lumber Short span, less than 24-0 (7.3 m) Dimensional lumber [2 8, 2 10, 2 12] Laminated veneer lumber Short to medium span, 16-0 to 30-0 (4.9 to 9.1 m) 1-3/4 (44 mm) thick laminated joists Wood I-joists Small to medium span, 20-0 to 60-0 (6 to 18.3 m) Lightweight 3/8 (10 mm) laminated strand lumber, oriented strand board, or plywood web; 1-1/2, 2, or 3 (38, 51, 76 mm) wide laminated veneer lumber or lumber flange Shop-fabricated wood trusses Medium span, 40-0 to 60-0 (12.2 to 18.3 m) Trusses [2 4], wood chords and webs, steel plate connectors Metal web wood joists Medium to long span, 40-0 to 60-0 (12.2 to 18.3 m) Wood chords, 20-gauge steel webs Medium to long span, 40-0 to 60-0 (12.2 to 18.3 m) Wood chords, 1 to 1-1/2 (25 to 38 mm) diameter tubing webs, depths to 40-0 (12.2 m) Long to very long, span 60-0 to 100-0 (18.3 to 30.4 m) Double [2 6] chords, 2 (51 mm) diameter webs, depth to 63 (1.6 m) TYPES OF FABRICATED TRUSSES 6.33 WOOD I-JOIST FLOOR FRAMING DETAIL 6.35 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 59 FL O O R CO NST RUCTION ASSEMBLIES FLOOR DETAILS AT BEARING INTERIOR PARTITIONS 6.36 FLOOR CANTILEVERS 6.37 STEEL JOIST FLOOR FRAMING Joists may come factory-punched, with openings of approximately 1-1/2 by 4 in. (38 by 102 mm) on center. NOTE 6.37 a. Any extension greater than 2 ft (610 mm) must be engineered. b. If space above is to be heated, insulate between joists and provide cuts in blocking as shown. Contributors: Timothy B. McDonald, Washington, DC. Joseph A. Wilkes, Wilkes and Faulkner, Washington, DC. John Ray Hoke, Jr., FAIA, Washington, DC. FRAMING OF FLOOR OPENING 6.38 BUILDING ST RU CT U R E AN D SH E LL 59 09_9780470889015_ch06.qxd:WILEY 60 9/19/11 10:24 AM Page 60 BUILD ING ST RU CT URE AND SHELL FLOOR CONSTRUCTION ASSEMBLIES FLOOR JOISTS BEARING ON FOUNDATION 6.40 FLOOR FRAMING AT EXTERIOR WALL 6.39 FLOOR DECKS AND SLABS CONCRETE FLOOR SYSTEMS CONCRETE SLABS 6.41 SLAB TYPE USES ADVANTAGES DISADVANTAGES Flat plate Moderate spans. Hotels, motels, dormitories, condominiums. Most economical floor system; has the lowest structural thickness. Inexpensive formwork, ceilings may be exposed, fast erection, flexible column location. Penetrations for piping and ductwork through slab near columns must be avoided. Spandrel beams may be necessary. Excess concrete for longer spans, low shear capacity, greater deflections. Flat slab Buildings supporting very heavy loads. Warehouses, industrial structures, parking structures. When live loads exceed 150 psf (7.182 Pa), flat slabs are by far the most economical. Formwork is costly. Banded slab High-rise buildings; same use as flat plates if flying forms can be used more than 10 times. Advantages of a flat plate; permits a longer span in one direction. Resists greater lateral loads in direction of beams. Typically posttensioned, minimum slab thickness. Must reuse formwork many times to be economical. Joist slab Best scheme if slabs are too long for a flat plate and the structure is not exposed. Slab thickness between joints is determined by fire requirements. Most economical if beams are the same depth as the joists. Appropriate building types: schools, offices, churches, hospitals, public and institutional buildings, buildings with moderate loadings and spans. Minimum concrete and steel; minimum weight, thus reduced column and footing size; long spans in one direction; accommodates poke-through electrical systems. Unattractive for an exposed ceiling; formwork may cost more than flat plate. Skip joist slab Same uses as for joist slabs, especially for longer fire ratings. For large projects, should be less expensive than a joist slab. Uses less concrete than joist slab; incurs lower steel rebar placing costs; joist space is used for mechanical systems; permits lights and equipment to be recessed between joists. Similar to joist slab; joists must be designed as beams; forms may require special order. One-way beam and slab Parking garages, especially with posttensioning. Long span in one direction. Long span of about 60 ft (18.3 m) must be prestressed unless beams are quite deep. Shallow beams will deflect excessively. Beams interfere with mechanical services; more expensive forms than flat plate. Waffle slab Prominent buildings with exposed ceiling structure; same types as are suitable for flat slab, but with longer spans. Longer two-way spans; exposed ceiling pattern; heavy load capacity. Drop panels can be diamond shaped, square, or rectangular. Formwork costs more and uses more concrete and steel than a joist slab. Column spacing should be multiples of pan spacing to ensure uniformity of drop panels at each column. Two-way slab and beam Portions of buildings in which two-way beam framing is needed for other reasons; industrial buildings with heavy concentrated loads. Long span in two directions; small deflection; can carry concentrated loads. High cost of formwork and structural interference with mechanical systems. NOTES 6.40 a. Continuous bridging is required between each joist above a beam. Solid blocking in other spaces may be used in lieu of bridging. b. When a bearing wall is above, studs must align with joists below. Contributors: American Iron and Steel Institute, Washington, DC. Kenneth D. Franch, PE, AIA, Aguirre, Inc., Dallas, Texas. Charles M. Ault, Setter, Leach, & Lindstrom, Architects & Engineers, Minneapolis, Minnesota. 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 61 FL O O R CO NST RUCTION ASSEMBLIES BUILDING ST RU CT U R E AN D SH E LL FLAT PLATE 6.42 JOIST SLAB 6.45 WAFFLE SLAB 6.48 FLAT SLAB 6.43 SKIP JOIST SLAB 6.46 TWO-WAY SLAB AND BEAM 6.49 BANDED SLAB 6.44 ONE-WAY BEAM AND SLAB 6.47 PRECAST CONCRETE DECKS AND SLABS Natural-weight (150 psf) or lightweight concrete (115 psf) is used in standard precast concrete slab construction. Concrete topping is usually normal-weight concrete with a cylinder strength of 3000 psi. All units are prestressed. METAL FLOOR DECKS Metal floor decks provide a working platform, eliminating temporary wood planking in high-rise use. Composite decks provide positive reinforcement for concrete slabs. Both noncomposite and composite decks serve as forms for concrete, eliminating the need for forming and stripping. Acoustical treatment is possible. Electric raceways may be built into the floor slab. Metal floor decking provides economical floor assemblies. ELECTRICAL TRENCH DUCTS Electrical raceways may be built into floor slabs by using cellular deck or special units that are blended with plain deck. Two-way distribution is achieved by using trench ducts that sit astride the cellular units at right angles. 61 09_9780470889015_ch06.qxd:WILEY 62 9/19/11 10:24 AM Page 62 BUILD ING ST RU CT URE AND SHELL ELECTRICAL TRENCH DUCT 6.50 ROOF CONSTRUCTION FLOOR CONSTRUCTION EXPANSION CONTROL SEISMIC JOINT COVERS WITH FLOORING INSERT 6.53 A large selection of prefabricated assemblies to cover interior expansion joints is available. Fire-rated barrier-type inserts are available and applicable to most assemblies. Expansion joint covers that will respond to differential movement, both laterally and horizontally should be provided at joints in structures, located where seismic action may be expected or where differential settlement is anticipated. EXPANSION JOINT COVER AT FLOOR AND WALL 6.52 FLOOR DECK ACCESSORIES A convenient, economical means of supporting lightweight acoustical ceilings is to attach a suspension system to hanger tables at side laps, pierce tabs driven through the deck, or prepunch tabs in the roof deck. Do not use this tab-and-metal deck arrangement to support plaster ceilings, piping, ductwork, electrical equipment, or other heavy loads. Such elements must be suspended directly from structural members or supplementary subframing. FLOOR DECK ACCESSORIES 6.51 ROOF CONSTRUCTION ROOF TYPES AND FRAMING Interior design and construction can interact with roof framing in the placement or removal of interior partitions and during the installation of ceilings and ceiling-mounted equipment. Interior space is often shaped by roof forms, and structural elements may be exposed to view. Skylights must be carefully integrated with roof framing. Check code and manufacturer’s requirements for all ventilation hole sizes cut in blocking web. Contributors: Donald Neubauer, PE, Neubauer Consulting Engineers, Potomac, Maryland. Walter D. Shapiro, PE, Tor, Shapiro & Associates, New York, New York. Paul Bonsall and Robert D. Abernathy, J. N. Pease Associates, Charlotte, North Carolina. GABLE ROOF 6.54 FLAT ROOF 6.55 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 63 ROOF CONSTRUCTION GAMBREL ROOF 6.56 MANSARD ROOF 6.57 BUILDING ST RU CT U R E AN D SH E LL SHED ROOF 6.59 COLD-FORMED STEEL ROOF TRUSSES 6.60 SHOP-FABRICATED WOOD TRUSSES HIP ROOF 6.58 Shop-fabricated wood trusses have been used in building construction since 1953, when the metal connector plate was invented. The metal plates are punched with barbs that grab onto the wood truss, thus reducing the hand nailing required to fabricate a structure. This system is primarily used for roofs with either pitched or parallel chord trusses. Individual trusses are cut from 2 4 or 2 6 TYPICAL PITCHED CHORD ROOF TRUSS 6.62 Contributors: Timothy B. McDonald, Washington, DC. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. American Iron and Steel Institute, Washington, DC. WOOD I-JOIST SKYLIGHT FRAMING DETAIL 6.61 dimensional lumber and can be spaced 24 in. (610 mm) or 48 in. (1,219 mm) on center. For typical residential construction, 24 in. (610 mm) on center is used. Exceptionally long spans are possible with shop-fabricated wood trusses, allowing the large, unencumbered interior spaces often required in commercial, agricultural, and other nonresidential building types. Truss chords and web members are placed in a vertical, plumb position, and maintain that position, resisting applied design loads throughout the life of the structure. 63 09_9780470889015_ch06.qxd:WILEY 64 9/19/11 10:24 AM Page 64 BUILD ING ST RU CT URE AND SHELL GLUE-LAMINATED CONSTRUCTION STRUCTURAL GLUE-LAMINATED SHAPES 6.63 Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. ROOF CONSTRUCTION 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 65 ROOF CONSTRUCTION BUILDING ST RU CT U R E AN D SH E LL ROOF DECKS AND SLABS ROOF STRUCTURE ASSEMBLIES 6.64 TYPE FIGURE MEMBER SIZES DEPTH CEILING REQUIRED SPAN SERVICE PLENUM THERMAL CAPACITY IMPACT SOUND AIRBORNE SOUND Wood rafter 5 to 13 (127 to 330 mm) Nom. joist 2 6, 8, 10, 12 Up to 22-0 (6.7 m) For visual or fire protection purposes Between rafters— one way Low Poor Fair Shop-fabricated wood truss Varies 12 to 120 (305 to 3,048 mm) — 30-0 to 50-0 (9.1 to 15.2 m) For visual or fire protection purposes Between trusses Low Poor Fair Cold-formed metal truss Varies — 100-0 to 200-0 (30.5 to 61 m) For visual or fire protection purposes Between trusses Low Fair Fair Steel joist (concrete) 11 to 75 (279 to 1,905 mm) Steel joists 8 to 72 Up to 96-0 (203 to 1,829 mm) (29.3 m) For visual or fire protection purposes Between joists Medium Fair Fair Steel joist (wood roof) 10 to 32 (254 to 813 mm) Steel joists 8 to 30 Up to 96-0 (203 to 762 mm) (29.3 m) For visual or fire protection purposes Between joists Low Poor Fair Steel frame 4 to 12 (102 to 305 mm) plus beam depth Concrete plank 20-0 to 60-0 (6.1 to 18.3 m), generally below 35-0 (10.7 m) For visual or fire protection purposes Under structure High Fair Fair Precast concrete 4 to 12 (102 to Concrete plank 305 mm) slab, plus 16 to 48 (406 to beam depth 1,219 mm) W, 4 to 12 (102 to 305 mm) D 20-0 to 60-0 (6.1 to 18.3 m), generally below 35-0 (10.7 m) No; provides finished flush ceiling Under structure High Fair Fair One-way concrete slab 4 to 10 (102 to — 254 mm) slab, plus beam depth 10-0 to 25-0 (3 to 7.6 m), more with posttension No Under structure High Good Good Two-way ribbed concrete slab 8 to 24 (203 to 610 mm) Standard dome forms 19 19 (483 483 mm), 30 30 (762 762 mm), 6 to 20 (152 to 508 mm) D 25-0 to 60-0 (7.6 to 18.3 m), more with prestressing No Under structure High Good Good Concrete flat slab 5 to 16 (127 to 406 mm) Min. slab thickness Up to 40-0 5 (127 mm) without (12.2 m), more with drop panel, 4 prestressing (102 mm) with one No Under structure High Good Good Source: Adapted from Roger K. Lewis, FAIA, and Mehmet T. Ergene, architect, Roger K. Lewis and Associates, Washington, DC. 65 09_9780470889015_ch06.qxd:WILEY 66 9/19/11 10:24 AM Page 66 BUILD ING ST RU CT URE AND SHELL ATTIC VENTILATION METAL ROOF DECKING Some of the many types of metal roof decking include: • • • • • • • STAIRS AND RAMPS Roof decking Composite deck Permanent forms for self-supporting concrete slabs Raceway (composite or noncomposite) Acoustical metal decking Acoustical cellular deck (composite or noncomposite) Vented roof deck (used with lightweight insulating concrete fill) Small openings up to 6 by 6 in. (152 by 152 mm) or 6 in. diameter usually may be cut in a roof or floor deck without reinforcing the deck. Openings up to 10 by 10 in. (254 by 254 mm) or 10 in. diameter require reinforcing of the deck either by welding a reinforcing plate to the deck all around the openings or by providing channelshaped headers and/or supplementary reinforcing parallel to the deck span. Larger openings should be framed with supplementary steel members so that all free edges of the deck are supported. Ventilation of attics can cause as many problems as it solves, if not designed and constructed carefully. The best understanding of the interrelated issues surrounding the control of heat, air, and moisture (HAM) inside attics, and the transfer of HAM to the building interior, suggests that, like crawl spaces, it may be preferable to treat the attic as part of the interior conditioned environment. This is especially true when heating, ventilating, and air conditioning (HVAC) equipment and ductwork are located in the attic. VENT APPLICATIONS 6.67 METAL ROOF DECK SECTION 6.65 METAL ROOF DECK TYPES 6.66 TYPE FIGURE REMARKS SPAN WIDTH MAXIMUM LENGTH Economy Most economical deck for shorter spans; use with 1 or more insulation 2-6 to 8-0 (0.8 to 2.4 m) 32 to 33 (813 to 838) 42-0 (12.8 m) Narrow rib (1 wide) Use with 1/2 insulation; maximum surface area on top for adhering insulation 4-0 to 11-0 (1.2 to 3.4 m) 36 (914) 42-0 (12.8 m) S TAIR S A ND R AM P S STAIRS Stairways are an essential component in the circulation and egress systems of most buildings. In the United States, they are also the site of accidents that, annually, result in approximately 4,000 deaths and 1 million injuries requiring hospital treatment. For these reasons, stairway design is strictly controlled by building regulations. REGULATIONS The information contained in this section summarizes most International Building Code (IBC) and access regulation requirements. The information in this chapter is based on IBC 2009 and 2010 ADA Standards for Accessible Design. Check authorities having local jurisdiction for additional requirements. Contributors: Donald Neubauer, PE, Neubauer Consulting Engineers, Potomac, Maryland. Walter D. Shapiro, PE, Tor, Shapiro & Associates, New York, New York. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. Erik K. Beach, Rippeteau Architects, PC, Washington, DC. David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Consult the IBC for stairway requirements to determine dimensional limits for treads, risers, landings, and stair widths. Verify that local codes are not more restrictive. Refer to the Americans with Disabilities Act (ADA) for accessibility requirements regarding stairs. Treads and risers within a flight must be uniform in size within close tolerances. Treads must be slip resistant. Carpeting or other stair coverings should be applied securely and should not create a nosing radius greater than permitted. Handrails, guardrails, and stairways themselves must meet structural load requirements. handrails. Only requirements for handrails apply in existing buildings. These requirements do not apply where there is an accessible route between floors served by the stairs. Access regulations in some localities require that flooring material strips of contrasting color be located at the top approach to a stair and at the lowest tread. These markings are intended to aid the visually impaired in identifying the limits of the stair. The application of such markings may be appropriate even where not required, particularly where a high proportion of elderly or visually impaired users are anticipated. ACCESSIBILITY The 2010 ADA Standards for Accessible Design require that all newly constructed stairs that are part of a means of egress must comply with requirements for accessible treads, risers, and STAIR TYPE Stair type refers to its design and plan layout. Stair types vary and are subject to code requirements. Stair type selection depends on 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 67 STAIRS AND RAMPS BUILDING ST RU CT U R E AN D SH E LL the space available, the starting and ending points required of the stair, and the appearance desired. Egress stairs must be enclosed as required by building codes, but the designer can vary the openness of nonegress stairs. STAIR DIMENSIONS Layout refers to the overall horizontal and vertical dimensions required to meet functional and building code requirements. This includes determining the width, total rise, and run of the stair as well as space for landings. Minimum stair widths are defined by building and accessibility codes, based on occupancy, tread and riser dimensions, handrail dimensions and positions, headroom requirements, and distance between landings. STAIR TYPES 6.68 Tread and riser dimensions are proportionally related to each other. The tread and riser proportion, or pitch, affect safety as well as the ease of using the stair. Code requirements are minimums. Details of construction include how the treads and risers are supported, handrail profiles and construction, materials used, and other finish considerations, including slip resistance. Maintain a minimum headroom of 6 ft 8 in. (2,032 mm). Avoid flights with fewer than three risers, to minimize tripping hazards. If one or two risers are used, increase the tread depth and clearly mark the level changes. 67 09_9780470889015_ch06.qxd:WILEY 68 9/19/11 10:24 AM Page 68 BUILD ING ST RU CT URE AND SHELL The use of door alcoves is recommended to prevent stairway doors from obstructing the egress travel path. STAIRS AND RAMPS RETURN STAIR PLAN LAYOUT 6.69 MINIMUM WIDTH The minimum width of any straight stair is 36 in. (914 mm) when the occupant load is less than 50. The minimum width is 44 in. (1,118 mm) when the occupant load is 50 or more. Handrails may encroach no more than 4-1/2 in. (114 mm) on each side. For large occupancies, calculate the minimum width according to the exit width provisions of the IBC. When the stair serves an area of evacuation assistance, the minimum clear width between handrails must be 48 in. (1,219 mm). In residential occupancies, wider stairways allow for easier movement of furniture. For commercial occupancies, wider stairways allow for more comfortable circulation when two people are passing or carrying objects. HORIZONTAL STAIR LAYOUT Steps involved in sizing the horizontal layout of the stair are as follows: 1. Determine the riser height: The number of risers required determines the number of treads required. • For standard straight stairs, begin the calculation by taking the total rise of the stairway, in inches, and dividing by 7 in. (179 mm). This is a comfortable riser height and is the maximum allowed for most commercial stairways. • If the result is not a whole number, select the next-highest whole number and divide that number into the total rise. This establishes a riser height of less than 7 in., which is a whole number and is the number of risers required. • The number of treads is one less than this number for a straight-run stair and two less for a return or L-shaped stair (the landing takes the place of one tread). • For straight-run residential stairways where allowed by code, divide by 7.75 in. (197 mm). This is the maximum allowable riser height for Group R-3 occupancies and within dwelling units in Group R-2 occupancies. 2. Determine the proportion between the riser and the tread dimensions: Stair dimensions are based on the normal stride of a person while ascending and descending a stair. • Several formulas relating rise and tread have been proposed through the years, but one of the most common is: 2R T = 25 or T = 25 – 2R where R is the riser height and T is the tread depth. • The IBC specifies a minimum tread depth of 11 in. (279 mm) for commercial stairs and 10 in. (254 mm) for residential stairs. • For straight-run, L-shaped, T-shaped, and wide-U stairs, the total run is the number of treads multiplied by the tread depth. • For return stairs, an unequal number of risers and treads in the lower and upper flight is recommended, to allow the first riser of the upper landing to lead the last riser of the lower landing by one tread depth. The handrail can then make a clean switchback without having to offset vertically. DESIGN GUIDELINES FOR STAIRS 1. Width of stair: • Dwelling stairs: minimum 36-in. (914-mm) treads • Public exit stairs: minimum 44-in. (1,118-mm) treads • Rescue assistance area (ADA): 48 in. (1,219 mm) between handrails 2. Treads: • Dwellings: 10 in. (254 mm) minimum (nosing to nosing) • Other (ADA): 11 in. (279 mm) minimum (nosing to nosing) • Uniform depth within one flight 3. Risers: • Dwellings: 7-3/4 in. (197 mm) maximum • Other (ADA): minimum 4 in. (102 mm); maximum 7 in. (178 mm) • Uniform height within one flight 4. Nosing: maximum 1-1/4 in. (32 mm) with 60° under nosing; maximum 1/2 in. (13 mm) radius at edge RETURN STAIR SECTION LAYOUT 6.70 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 69 STAIRS AND RAMPS BUILDING ST RU CT U R E AN D SH E LL HANDRAIL AND GUARD HEIGHTS HORIZONTAL LAYOUT 6.71 Per 2010 ADA Standards for Accessible Design, the height of a handrail above stair nosings should be 34 to 38 in. (864 to 965 mm). For open stairways more than 30 in. (762 mm) above the floor, the IBC also requires a guard 42 in. (1,067 mm) above the nosing in addition to a handrail. Guards should be 42 in. (1,067 mm) minimum in most commercial construction. The IBC allows guards to be 36 in. (914 mm) on opensided walking surfaces in Group R-3 occupancies (dwellings). Guards on the open sides of stairs in Group R-3 occupancies and within individual dwelling units in Group R-2 occupancies must be a minimum of 34 in. (864 mm) measured from the nosing. Where the top of a guard also serves as a handrail on the open sides of stairs in Group R-3 and individual dwelling units of Group R-2 occupancies, the top of the guard must not be less than 34 in. (864 mm) and not more than 38 in. (965 mm) above the nosings. Handrails should be easy to grip and fit the hand. The recommended diameter is 1-1/4 to 1-1/2 in. (32 to 38 mm) for round handrails and a similar size for an elliptical or rounded square-edge section. Handrails should be structurally designed so that both downward (vertical) and lateral (horizontal) thrust loads are considered. Extensions of handrails at the top and bottom of stairs may affect the total length of the required run. Verify extensions required by local codes or 2010 ADA Standards for Accessible Design when designing a stair. Handrails must extend beyond the top and bottom treads, as required by code. At the inside turn of return stairs, the handrail must be continuous. The ends of the handrail must return to either the wall or a guard, or to the floor, or they must be continuous to the next handrail of an adjacent stair flight. The IBC and ADA require a minimum clearance of 1-1/2 in. (38 mm) between the inside of the handrail and the wall. Some studies have suggested that a better dimension is 2 in. (51 mm). This larger dimension is good for general graspability and works better for a person wearing gloves. For children, an additional handrail should be 1-1/8 to 1-1/2 in. (29 to 32 mm) in diameter and mounted 22 to 28 in. (559 to 710 mm) above the nosing line. RAILINGS AT WALLS 6.73 LANDINGS—SECTION 6.72 HANDRAILS, BALUSTRADES, AND GUARDS HANDRAILS Handrail requirements are governed by building and accessibility codes. Typically, handrails are required on both sides of stairs. Exceptions include dwelling units and private dwellings. In these cases, only one handrail is required. Handrails are not required for changes in room elevations of three or fewer risers in dwelling units and sleeping units in Group R-2 and R-3 occupancies. Handrails are also not required in Group R-3 occupancies where there is a single riser at an entrance or egress door. Handrail gripping surfaces must be continuous, without interruption by newel posts or other obstructions. Handrails in dwelling units are allowed to have newel posts at landings and volutes at the lowest tread. For wide stairways used as a means of egress, intermediate handrails are required so that all portions of the stairway width are within 30 in. (762 mm) of a handrail. On monumental stairs, handrails must be located along the most direct path of egress travel. Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Mark J. Mazz, AIA, Hyattsville, Maryland. 69 09_9780470889015_ch06.qxd:WILEY 70 9/19/11 10:24 AM Page 70 BUILD ING ST RU CT URE AND SHELL HANDRAILS 6.74 HANDRAIL DIMENSIONS 6.75 STAIRS AND RAMPS 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 71 STAIRS AND RAMPS BUILDING ST RU CT U R E AN D SH E LL FULL WALL STRINGER 6.78 ELEVATION OF FACE STRINGER 6.76 NOTCHED WALL STRINGER 6.79 NO WALL STRINGER 6.77 71 09_9780470889015_ch06.qxd:WILEY 72 9/19/11 10:24 AM Page 72 BUILD ING ST RU CT URE AND SHELL STAIRS AND RAMPS Section 505.3 of the 2010 ADA Standards for Accessible Design require handrails to be continuous along their lengths and not obstructed along their tops and sides. Their bottoms may not be obstructed for more than 20% of their lengths. WALL BRACKETS 6.80 Horizontal projections must be a minimum of 1-1/2 in. below the bottom of the handrail’s gripping surface, with a different requirement for some larger handrails. Section 505.10 requires handrails to extend at the slope of the stair flight for a horizontal distance equal to a minimum of one tread depth past the last riser nosing. PLAN SHOWING HANDRAIL EXTENSIONS 6.83 ACCESSIBLE HANDRAIL AND GUARDRAIL DIMENSIONS 6.81 DESIGN GUIDELINES FOR METAL STAIR HANDRAILS The IBC and ADA require handrails to be circular in cross section, with a dimension between 1-1/4 and 2 in. (38 and 51 mm). Other shapes are allowed if the perimeter dimension is between 4 and 6-1/2 in. (102 and 165 mm) and the maximum cross-sectional dimension does not exceed 2-1/4 in. (57 mm). The 2010 ADA Standards for Accessible Design require that handrail gripping surfaces have rounded edges. HANDRAIL GRASPABILITY 6.82 Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. The 2009 IBC requires that handrails be easily grasped and allows for two types, Type I and Type II. Type I handrails are required for most construction, but Type II handrails are also allowed for Group R-3 (residential) occupancies, within dwelling units in Group R-2 occupancies, or accessory to the individual dwelling units in Group R-2 occupancies. Edges must have a minimum radius of 0.01 in. (0.25 mm). 1. Stair rails: • Height in dwellings: 36 in. (914 mm) • Height in exit stairs: 42 in. (1,067 mm) • Arrange rails so that a sphere 4 in. (102 mm) in diameter cannot be passed through • Arrange rails to discourage climbing • Concentrated load nonconcurrently applied at the top rail must be 200 pounds force (1,156 N) in vertical downward and horizontal directions. The test loads are applicable for railings with supports not more than 8 ft (2.4 m) apart 2. Handrails: • Dwellings: on one side only, required • Other (ADA): required on both sides • Height: 34 to 38 in. (864 to 965 mm) • Grip surface: 1-1/4 to 1-1/2 in. (32 to 38 mm) • Clearance at wall: 1-1/2 in. (38 mm) • Projecting or recessed • Extension at top of run: 12 in. (305 mm) • Extension at bottom of run: horizontal depth of tread • When a guardrail more than 38 in. (965 mm) high is used, a separate handrail should be installed • Nothing should interrupt the continuous sliding of hands 3. Regulators and standards: building codes, ADA, ASTM International, American National Standards Institute (ANSI), National Fire Protection Association (NFPA), and Occupational Safety and Health Administration (OSHA) 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 73 STAIRS AND RAMPS STRINGER DETAILS 6.84 BUILDING ST RU CT U R E AN D SH E LL TREADS, RISERS, AND NOSINGS TREADS The minimum dimensions for stair treads are indicated in the building codes. If space permits, research has shown that slightly deeper treads than the minimum are more comfortable and safer to use. Tread material should be nonslip, but not so rough that feet may be caught on the nosing. RISERS Straight, vertical risers are permitted by the IBC and the ADA; however, treads with nosings are more comfortable for the user. Treads must be designed to follow requirements that prevent sharp or abrupt edges, which may catch a person’s foot and present a safety hazard. Open risers may not be used in most situations. STAIR ELEMENTS 6.86 RAILING DETAILS 6.85 RISER DESIGN 6.87 NOSINGS The IBC limits the amount of nosing overhang to 1-1/4 in. (32 mm), whereas the ADA limits the amount to 1-1/2 in. (38 mm). A 1-in. (25-mm) overhang is usually sufficient. The ADA limits the radius of the leading edge of a tread to 1/2 in. (13 mm), whereas the 2009 IBC limits the radius to 9/16 in. (14 mm). To comply with both regulations, use a maximum radius of 1/2 in. (13 mm). 73 09_9780470889015_ch06.qxd:WILEY 74 9/19/11 10:24 AM Page 74 BUILD ING ST RU CT URE AND SHELL WOOD NOSINGS 6.88 STAIRS AND RAMPS WOOD STAIR SECTION 6.90 AREA OF RESCUE ASSISTANCE The ADA and building codes identify requirements for areas of rescue assistance. Areas of rescue assistance are stairway clear widths that allow for easier maneuverability of rescue personnel and physically challenged persons, as well as the clear dimensions at specified areas on landings provided as waiting areas for a person in a wheelchair. PLAN DIMENSIONS REQUIRED FOR RESCUE ASSISTANCE (ADA) 6.89 TREADS AND RISERS AT HOUSED STRINGER 6.91 WOOD STAIRS Wood stairs used in private, residential applications usually are not governed by the ADA; however, wood stairs in commercial facilities and places of public accommodation must conform to 2010 ADA Standards for Accessible Design. Verify requirements that may differ from the general recommendations provided here. In general, a minimum interior stair width of 36 in. (914 mm) should be provided. The minimum headroom is 6 ft 8 in. (2,032 mm), as measured vertically from a diagonal line connecting tread nosings to the underside of the finished ceiling or stair landing directly above the stair run. The recommended headroom is 7 ft (2,134 mm). Only handrails and stair stringers may project into the required width of a stair. Use the following guidelines: • The maximum handrail projection is 4-1/4 in. (114 mm). • To comply with 2010 ADA Standards for Accessible Design, no projections are allowed into the minimum required stair width. • The width of a landing or platform should be at least as wide as the stair. • The maximum vertical rise of a stair between landings is 12 ft (3,658 mm). • The riser height should be 4 in. (102 mm) minimum and 7 in. (178 mm) maximum. • The tread depth should be 11 in. (279 mm) minimum, measured from riser to riser. Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Janet B. Rankin, AIA, Eric K. Beach, and Annica S. Emilsson, Rippeteau Architects, PC, Washington, DC. The Baumgardner Architects, Seattle, Washington. • Variation in adjacent treads or risers should not exceed 3/16 in. (5 mm). The maximum variation allowed in the tread depth or riser height within a flight of stairs is 3/8 in. (10 mm). 2010 ADA Standards for Accessible Design require uniform treads and risers. • Nosings project 1-1/4 in. (31 mm) maximum. Verify building codes and 2010 ADA Standards for Accessible Design requirements. • Open riser stairs do not comply with 2010 ADA Standards for Accessible Design. CLOSED RISER STAIR—WOOD FINISH 6.92 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 75 STAIRS AND RAMPS BUILDING ST RU CT U R E AN D SH E LL DIMENSIONED LUMBER STAIR 6.93 CLOSED RISER STAIR—CARPET FINISH 6.94 METAL STAIRS Metal stairs are normally constructed of steel and fabricated in the shop to fit the dimensions required by the opening in which they are to be used. Treads and landings are typically filled with 1-1/2 to 2 in. (38 to 51 mm) of concrete. A finish material can then be applied over the concrete. Balusters are anchored by welding, bolting, or screwing them to the stringers. Glass balusters are anchored into a special U-shaped channel, which is attached to the edge of the stringer. A similar detail can be used for glass railings. METAL PAN STAIR SECTION 6.96 OPEN RISER STAIR 6.95 Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. The Baumgardner Architects, Seattle, Washington. Janet B. Rankin, AIA, Rippeteau Architects, PC, Washington, DC. 75 09_9780470889015_ch06.qxd:WILEY 76 9/19/11 10:24 AM Page 76 BUILD ING ST RU CT URE AND SHELL STAIRS AND RAMPS U-TYPE CONCRETE STAIRS 6.97 FREESTANDING CONCRETE STAIR 6.98 HELICOIDAL CONCRETE STAIR 6.99 CANTILEVER CONCRETE STAIR 6.100 NOTES 6.97 a. Consult structural engineer for reinforcing steel placement. b. Verify required dimensions and clearances for code compliance. 6.98 Limit hinge dimension to requirements of stair. 6.99 Use of helicoidal concrete stairs depends on a fixed-end support and small support deflection. 6.100 a. Reinforcing steel must develop full bond in masonry walls and have full development length in concrete walls. b. Detail of shear key is similar to Detail C in Figure 1.145. Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Krommehoek/McKeown and Associates, San Diego, California. Karlsberger and Companies, Columbus, Ohio. 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 77 STAIRS AND RAMPS ALTERNATE STAIR TYPES Alternate stair types include winding stairs, curved stairs, and spiral stairs. Generally, the IBC does not allow these types of stairs to be used for egress except within private dwelling units. Spiral stairs may also be used as egress from a space not more than 250 sq ft (23 sq m) and serving not more than five occupants. When these alternate stair types are allowed, they must meet the minimum dimensional requirements of the codes. Riser heights for curved and winding stairs must meet the code maximums of 7 in. (178 mm) for commercial stairs and 7-3/4 in. (197 mm) for residential stairs. Riser heights for spiral stairs must be such that a clear headroom of 78 in. (1,981 mm) is provided, but in no case can the riser height be greater than 9-1/2 in. (241 mm). BUILDING ST RU CT U R E AN D SH E LL Spiral stairs are available with 22-1/2°, 27°, and 30° angle treads. The most common are 27° and 30° tread angles because these can maintain at least a 7-1/2-in. (190 mm) dimension 12 in. (305 mm) from the center pole. Tread selection depends on the riser height desired, the total rise, the headroom clearance requirements, and the top and bottom riser orientation. CURVED STAIR ELEVATION 6.105 Critical minimum headroom dimensions should be calculated based on a three-quarter turn of the stair, even if a full 360° turn is being used to travel the full rise. SPIRAL STAIR PLAN VIEW 6.103 WINDING STAIRWAY 6.101 CURVED STAIR PLAN 6.106 SPIRAL STAIR DETAIL 6.104 SPIRAL STAIRS Spiral stairs are composed of wedge-shaped treads supported from a central column, usually 4 in. (102 mm) in diameter. Prefabricated spiral stairs are commonly made from steel. Spiral stairs are available in custom sizes. To meet building code requirements as a means of egress, stairs must be at least 5 ft (1.5 m) in diameter to meet the 26 in. (660 mm) clear-width requirement, assuming a 4 in. (102 mm) center post. Larger diameters increase perceived comfort, ease of use, and safety. CURVED STAIR REQUIREMENTS 6.107 SPIRAL STAIR ELEVATION 6.102 CURVED STAIRS Design considerations for curved stairs are similar to those for spiral stairs. A fabricated steel tube serves as a one-piece stringer to which treads are bolted or welded. Risers can be open or closed. Curved stairs may be part of a means of egress when they meet the following dimensional requirements: • The radius inside the stairway must be at least twice the width of the treads. • Treads must be a minimum of 10 in. (254 mm) at the narrow end, and at least 11 in. (279 mm) when measured at a point 12 in. (305 mm) from the narrower end of the tread. • In residential occupancies, treads must be at least 6 in. (52 mm) at the narrow end. Alternating tread devices are not permitted as egress, except in very limited storage or manufacturing occupancies for areas under 250 sq ft (23 sq m). NOTE 6.102 For clarity, only one baluster per tread is shown. Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. David W. Johnson, Washington, DC. The Baumgardner Architects, Seattle, Washington. Janet B. Rankin, AIA, Rippeteau Architects, Washington, DC. Charles A. Szoradi, AIA, Washington, DC. 77 09_9780470889015_ch06.qxd:WILEY 78 9/19/11 10:24 AM Page 78 BUILD ING ST RU CT URE AND SHELL RAMPS STAIRS AND RAMPS RAMP AND RAMP LANDING EDGE 6.109 ACCESSIBLE RAMPS Ramps on accessible routes are required to comply with 2010 ADA Standards for Accessible Design. The standards require that ramp runs have a running slope not steeper than 1:12 (rise over run), with some exceptions for space limitations in existing sites, buildings, and facilities. To accommodate the widest range of users, guidelines recommend the provision of ramps with the least possible running slope. Wherever possible, accompany ramps with stairs for use by people who find long ramps a greater barrier than stairs, for example, individuals with heart disease or limited stamina. The cross slope of a ramp is the slope of the surface perpendicular to the direction of travel, measured rise over run. 2010 ADA Standards for Accessible Design limit cross slopes of ramp runs to a maximum of 1:48. Changes in level other than running slope and cross slope are not permitted on ramp runs. Surfaces must be stable, firm, and slip resistant. Carpet or carpet tile must be firmly attached, with a firm cushion or pad where either is used. Acceptable pile textures include level loop, textured loop, level cut pile, or level cut/uncut pile. The maximum allowable pile height is 1/2 in. (13 mm). Exposed edges of carpet must be fastened to the floor surface and trimmed along their entire length. Edge protection is required on each side of ramp runs and at each side of ramp landings, with some exceptions. A curb or barrier must prevent passage of a sphere 4 in. (102 mm) in diameter, where any portion of the sphere is within 4 in. (102 mm) of the finish floor or ground surface. In assembly areas, aisle ramps adjacent to seating that are not serving elements required to be on an accessible route are not required to comply with 2010 ADA Standards for Accessible Design. COMPONENTS OF A RAMP 6.108 RAMP EDGE BARRIER 6.110 RAMP HANDRAILS Provide continuous handrails at both sides of ramps and at the inside of handrails of switchback or dogleg ramps. If handrails are not continuous at bottom, top, or landings, provide handrail extensions. The ends of handrails must be returned smoothly to floor, wall, or post. HANDRAIL DESIGN 6.111 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 79 EXTERIOR VERTICAL ENCLOSURES BUILDING ST RU CT U R E AN D SH E LL RAIL AT RAMP 6.112 EXTERIOR VERTICAL ENCLOSURES EXTERIOR WALL WEATHER BARRIERS CLIMATE AND ENERGY Of primary importance to the shell of a building is the mediation between the exterior and interior environment. Proper design and detailing of the building enclosure requires an understanding of the specific characteristics of the desired interior environmental conditions and the specific exterior environmental conditions on both a macro and a micro scale. DEFINITIONS • Air barriers: Materials that form a continuous envelope around all sides of the conditioned space to resist the passage of air. An air barrier may or may not be a vapor retarder. • Vapor barriers and retarders: Terms used interchangeably. Materials that have a high degree of resistance to vapor diffusion. Their placement in an enclosure assembly will affect wetting and, more importantly, drying of the assembly. • Insulation: A material that slows the flow of heat through conduction. • Radiant barriers: A material, usually metallic or shiny, that reflects radiant thermal energy. • Weather or water-resistant barrier: A material that is resistant to the penetration of water in the liquid state, or is waterproof. It may or may not be an air barrier or vapor retarder. The face of the weather barrier is sometimes called the drainage plane. • Barrier wall: A wall that prevents absorbed moisture from penetrating to the interior. INTERIOR CLIMATIC INFLUENCE Environmental conditions to be maintained within the building also influence the design of the shell. Buildings with the following requirements need particular attention to system selection and detailing, in concert with consideration of the exterior climate: • • • • • • • • High or low levels of humidity Tight temperature tolerances Pressure differentials to the exterior High-reliability containment Acoustic isolation Protection from blast or forced entry High indoor air quality Other extraordinary requirements 79 09_9780470889015_ch06.qxd:WILEY 80 9/19/11 10:24 AM Page 80 BUILD ING ST RU CT URE AND SHELL HEAT, AIR, AND MOISTURE In addition to the obvious structural loads, the building enclosure must resist the transfer of heat, air, and moisture (HAM). The laws of physics dictate that heat always flows from hot to cold. Air moves through building enclosures by passing through porous materials or through holes and gaps in nonporous materials, based on differential air pressures. Moisture in the liquid state is water that occurs as rain, snow, and groundwater. Moisture in the vapor state moves through enclosures from zones of higher to lower vapor pressures. EXTERIOR VERTICAL ENCLOSURES COLD CLIMATES 6.114 • Include highly reliable enclosure systems to control HAM in all climate zones, without relying on building mechanical systems to dry interior air. • If metal stud backup systems are used, do not place thermal insulation between the studs. • Any paint or wallcovering is allowed on the interior finish. For residential buildings in cold climates, heat loss through the enclosure may be the largest component of total energy consumption. For large commercial buildings in moderate environments, daylighting schemes may save more energy, even though they may result in an enclosure with lower thermal resistance. HOT, HUMID CLIMATES 6.115 HOT CLIMATES (ZONES 1, 2, AND 3) • The mechanical system must provide dehumidification of interior air for drying. • Avoid any vapor-impermeable interior finishes such as vinyl wallcoverings that will trap moisture. • A radiant barrier may be incorporated into the cavity. • Taped joints in sheathing, board insulation, or a combination may provide an air barrier. • An air barrier is crucial to limit moisture transport through imperfections in the vapor retarder. ALL CLIMATES 6.113 Most jurisdictions require compliance with an energy conservation code. ASHRAE 90.1 and the International Energy Code are common model codes. These minimum standards should be exceeded by 20 to 50%, if possible. EXTERIOR ENCLOSURE WALLS BASIC EXTERIOR WALL ASSEMBLY TYPES Exterior wall assemblies fall into three basic categories: • Barrier walls • Drainage walls • Pressure-equalized walls MIXED CLIMATES (ZONES 3 AND 4) • All materials must be relatively vapor permeable to allow drying in both directions, because seasons change the direction of heat flow and vapor drive. Contribute to minimizing energy usage Incorporate environmentally sensitive materials Ensure good indoor air quality and occupant comfort Be durable For high-performance building projects, the enclosure could help generate energy, return nutrients to the environment, and filter pollutants. Buildings are major consumers of energy, so the enclosures should be part of a strategy to reduce energy consumption. In fact, creating a well-performing enclosure is considered to be the first step in reducing energy usage, ahead of other more sophisticated strategies, such as high-performance mechanical systems. A thorough understanding of the interior and exterior environments is paramount. ALL CLIMATES (ZONES 5 TO 8) • Any paint or wallcovering is allowed on the interior finish. • Mechanical system is not required to dry interior air. The building shell should be a major part of the sustainable strategy. At a minimum, the shell should: • • • • INTERIOR CONSIDERATIONS FOR CLIMATE ZONES COLD CLIMATES (ZONES 5 TO 8) SUSTAINABILITY AND ENERGY BARRIER WALLS MIXED CLIMATES 6.116 Most barrier walls rely on the thickness of water-resistant materials to absorb moisture and then dry when precipitation stops. Typical assemblies include: • Cast-in-place concrete • Precast concrete • Concrete masonry units Face-sealed barrier walls rely on a perfect continuous seal at the exterior face. Common assemblies include: • Exterior insulation and finish systems (EIFS) • Windows with a single sealant bead DRAINAGE WALLS Drainage walls resist air and moisture penetration with an outer layer that blocks the bulk of precipitation and an inner water barrier. At drainage cavity walls, a cavity of 3/4 in. (19 mm) or more is present in front of the drainage plane. If the water barrier is not also an air barrier, then another layer of the wall assembly must serve as an air barrier. Common drainage cavity walls include: • Brick veneer • Some metal panels Typical internal drainage plane walls include: • Portland cement stucco over lath and a weather barrier • Wood or vinyl siding • Water drainage EIFS PRESSURE-EQUALIZED WALLS Pressure-equalized rainscreen walls use a drainage cavity, with the air pressure in the cavity approximately equal to the exterior air pressure. Typical pressure-equalized rainscreen walls include some unitized stone or metal panels and many curtain wall systems. 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 81 EXTERIOR VERTICAL ENCLOSURES EXTERIOR WALL SKIN TILT-UP CONCRETE Tilt-up concrete is a fast, economical method of enclosing a building with durable, load-bearing walls. Tilt-up construction consists of reinforced concrete wall panels cast in a horizontal position on site, then tilted up with a crane into their final vertical position. They are usually cast on the concrete ground slab built for the building under construction, although molds of other materials are sometimes used. The site-cast panels are the load-bearing elements for the roof members, and they provide both interior and exterior finish. The BUILDING ST RU CT U R E AN D SH E LL building shell can be erected quickly, permitting interior work to proceed along with final joining and sealing of the envelope panels. The clear spans produced by the bar joist roof structure and the option for a hung ceiling allow interior partitions to be freely located. Tilt-up walls have been used in a variety of building types and heights, especially in single-story buildings with large, uncomplicated exteriors. The system is also used for multistory low-rise projects. Significant savings in time and formwork costs can be achieved, and the long lead times required for precast or structural steel components are often averted. Because most of the forming and erection work is done within the floor slab area, tilt-up systems work well in confined construction sites. EXTERIOR WALL ASSEMBLIES 6.117 EXTERIOR WALL ASSEMBLY NOMINAL WALL THICKNESS UNSUPPORTED HEIGHT U-FACTOR CONTROL OF HEAT, AIR, AND MOISTURE (HAM) AIRBORNE SOUND TRANSMISSION RESISTANCE CMU 8 Up to 13-0 (4 m) 0.56 Very poor HAM Good CMU (insulated) 12+ Up to 20-0 (6 m) 0.20 Very poor A and M, average H Good CMU and brick veneer (interior insulation) 4 + 2 + 4+ Up to 13-0 (4 m) with filled cavity 0.19 Poor A and water transmission Excellent Wood stud 6 Up to 20-0 (6 m) where L/d < 50-0 (15.2 m) 0.04 Average HAM Poor to fair Metal stud 5 Up to 13-0 (4 m) 0.10 Average A and M. Add insulation over sheathing to increase thermal performance Poor to fair Brick veneer on metal stud 4 + 2 + 6 Up to 15-0 (4.6 m) 0.10 Average A and M. Add insulation over sheathing to increase thermal performance Good Insulated sandwich panel 5 See manufacturer’s literature 0.05 (see manufacturer’s literature) Field-assembled systems generally lower performance; factory-insulated systems average performance Poor to good (see manufacturer’s literature) Concrete (insulated) 8+ Up to 13-0 (17-0 with reinforcement) 0.13 Poor M. average H and A Good Concrete and brick veneer (insulated) 4 + 2 + 8+ Up to 13-0 (4 m); 17-0 (5.2 m) with reinforcement 0.13 Average HAM Excellent Precast concrete 4+ Up to 12-0 (3.7 m) 0.85 Same as above Good 81 09_9780470889015_ch06.qxd:WILEY 82 9/19/11 10:24 AM Page 82 BUILD ING ST RU CT URE AND SHELL EXTERIOR VERTICAL ENCLOSURES TILT-UP CONCRETE 6.118 LEGEND A B C D E Skylights Built-up roofing and rigid insulation Steel deck and open-web steel joists Ductwork in open-web steel joists Radiant heat panels in suspended ceiling F G H I J K Fluorescent light fixture Window assembly Precast concrete panels Resilient tile flooring Slab on grade and concrete footing Rigid insulation Source: Based on Richard D. Rush, AIA, The Building Systems Integration Handbook (John Wiley & Sons, 1986). 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 83 EXTERIOR VERTICAL ENCLOSURES BUILDING ST RU CT U R E AN D SH E LL TILT-UP CONCRETE PANEL DETAILS 6.119 PRECAST CONCRETE ARCHITECTURAL WALL PANELS It is important to carefully distinguish between the more specialized architectural wall panel and the structural wall panel that is a derivative of floor systems. Form liner molds provide a wide variety of smooth and textured finishes. Finishes after casting (but prior to hardening) include exposed aggregate, broom, trowel, screed, float, and stippled. After hardening, finishes include acid etched, sandblasted, honed, polished, and hammered rib. It is customary to select a color range, as complete uniformity cannot be guaranteed. White cement offers the best color uniformity; gray cement is subject to color variations even when supplied by one source. Fine-aggregate color requires control of the mixture gradation; coarse-aggregate color provides the best durability and appearance. Contributors: Haynes Whaley Associates, Structural Engineers, Houston, Texas. Robert P. Foley, PE, Con/Steel Tilt-Up Systems, Dayton, Ohio. Sidney Freedman, Precast/Prestressed Concrete Institute, Chicago, Illinois. SINGLE-WYTHE MASONRY WALL SECTION 6.120 MASONRY EXTERIOR WALLS CONCRETE MASONRY UNIT EXTERIOR WALLS Single-wythe CMU walls may be either load bearing or non–load bearing supported by the building frame. CMU walls are subject to significant movement from shrinkage caused by initial drying and then ongoing movement caused by temperature and moisture content variations. Masonry units for the wall may be structural, though architectural units may provide more design options. Architectural units include split-faced, scored, integrally colored, ground-faced, and specially shaped or sized units. Glazed CMU and structural clay tile also may be used and are advantageous because they are less absorptive. Single-wythe masonry walls function as mass barrier walls. They absorb moisture during precipitation and then dry out. Control of heat flow is typically accomplished by adding insulation to the interior side or by inserting insulation into the cores of the CMU. 83 09_9780470889015_ch06.qxd:WILEY 84 9/19/11 10:24 AM Page 84 BUILD ING ST RU CT URE AND SHELL WALL ANCHORAGE DETAIL 6.121 EXTERIOR VERTICAL ENCLOSURES CLAY MASONRY WALLS Clay masonry, including brick used in veneer walls, can provide some of the most cost-effective, high-performance exterior wall assemblies available. The brick veneer must be supported by a structural backup, most typically CMU, wood studs, or cold-formed steel framing, but may also be placed over structural concrete or precast concrete. MASONRY CMU BACKUP 6.122 Source: Courtesy of Tom Van Dean, AIA, Kling. Contributors: Grace S. Lee, Rippeteau Architects, PC, Washington, DC. Stephen S. Szoke, PE, National Concrete Masonry Association, Herndon, Virginia. Brian F. Trimble, Brick Industry Association, Reston, Virginia. BRICK VENEER ON WOOD FRAMING 6.123 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 85 EXTERIOR VERTICAL ENCLOSURES BRICK VENEER ON CMU 6.124 BUILDING ST RU CT U R E AN D SH E LL THIN BRICK VENEER Thin brick veneer, also referred to as adhered veneer, is an application of thin brick veneer units between 1/2 and 1-3/4 in. (38 and 44 mm) thick on a backing system. The thin brick can be adhered to a stud backing, attached to a concrete masonry backing, cast into a concrete panel, or laid into a preformed modular panel. Thin brick panels can be prefabricated or laid in place, depending on the size or intricacies of the project. DIAGONAL STABILITY BRACING ANCHORAGE 6.127 THIN BRICK VENEER ON CMU 6.125 WINDOW OPENING 6.128 THIN BRICK VENEER ON WOOD OR COLD-FORMED METAL FRAMING 6.126 DOOR OPENING 6.129 COLD-FORMED METAL FRAMING AND BRACING Lightweight steel framing is cold formed, which means the components are manufactured by brake forming and punching galvanized coil and sheet stock. Cold-formed framing members consist of two basic types of components that are C-shaped in section: One type has 1/4-in. (6-mm) flanges folded inward; the other has no flanges. Studs, joists, and rafters are made with flanges to stiffen them so they will more readily stand vertically. Components without flanges (called tracks) have unpunched solid webs. For added strength, tracks are sized slightly larger than the flanged members so the tracks will fit snugly inside them as sill or top plates or as part of posts or headers. Cold-formed metal framing is strong and versatile. The strength and load-carrying capacity of a member can be increased simply by increasing the thickness, or gauge, of the metal; the dimensions of the member, or the spacing, do not necessarily have to be increased. There is little limitation on the length of steel framing members; joists or studs may be fabricated in lengths up to 40 ft (12.2 m). The disadvantages of cold-formed metal framing include lack of insulating qualities; difficulty in cutting, compared to wood; and dangerously sharper edges. Contributors: Grace S. Lee, Rippeteau Architects, PC, Washington, DC. Stephen S. Szoke, PE, National Concrete Masonry Association, Herndon, Virginia. Brian F. Trimble, Brick Industry Association, Reston, Virginia. Anthony Golebiewski, AIA, Kling, Philadelphia, Pennsylvania. Eric Glastier, Alexandria, Virginia. 85 09_9780470889015_ch06.qxd:WILEY 86 9/19/11 10:24 AM Page 86 BUILD ING ST RU CT URE AND SHELL HEAVY FIXTURE ATTACHMENT 6.130 EXTERIOR VERTICAL ENCLOSURES PARTITION-TO-WALL CONNECTION 6.134 EXTERIOR WOOD STUD SYSTEM 6.136 BACKING FOR CABINETS 6.131 HEAVY-TIMBER SILL—WIRE CHASE DETAIL 6.137 NAILABLE BASEPLATE 6.132 HEAVY-TIMBER WALL CONSTRUCTION Heavy-timber structures are typically enclosed with stressed-skin insulated panels, leaving the frame totally exposed on the interior. Heavy-timber construction is being updated with such materials as glue-laminated (glulam) members and proprietary concealed metal connections. INFILL WOOD STUD ASSEMBLY 6.135 WALL INTERSECTION FRAMING 6.133 Contributors: Joseph A. Wilkes, FAIA, Wilkes and Faulkner, Washington, DC. American Iron and Steel Institute, Washington, DC. Tedd Benson and Ben Brungraber, PhD, Benson Woodworking Company, Inc., Alstead New Hampshire. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. SURFACE-MOUNTED WIRE CHASE AT FOAM CORE PANEL 6.138 09_9780470889015_ch06.qxd:WILEY 9/19/11 10:24 AM Page 87 RO O F WINDOWS AND SK YLIGHTS STRUCTURAL INSULATED PANELS There are two main types of structural building panels: BUILDING ST RU CT U R E AN D SH E LL TYPICAL WIRE CHASE LOCATIONS IN PANELS 6.140 FIELD-ASSEMBLED WALL PANEL 6.141 • Stressed-skin panels: These are manufactured by gluing and nailing plywood skins to both sides of a wood frame, resulting in a unit that performs like an I-beam. Stressed-skin panels are not necessarily insulated. • Structural foam core panels: These fall into two groups: sandwich panels and unfaced panels. Sandwich panels are rigid-foam panels faced with two structural-grade skins, usually made of OSB or plywood. Unfaced structural foam core panels look like panels of stick framing with thermal insulation between the members, instead of blanket insulation. Interior and exterior finishes are applied to these panels in the field. The skins of structural building panels resist tension and compression, while the wood frame or core resists shear and prevents buckling of the skins. All structural foam core panels are insulated with a core of expanded polystyrene (EPS), extruded polystyrene, or urethane foam, ranging in thickness from 3-1/2 to 11-1/2 in. (89 to 292 mm). TYPICAL INTERMEDIATE PANEL SPLINE DETAIL 6.139 PANELIZED WALL CLADDING It is possible to panelize major pieces of complete wall assemblies. Panels are typically one structural bay wide and either one story high (if the design includes punched windows) or one spandrel high (if a horizontal strip window design is used). FACTORY-ASSEMBLED WALL PANEL 6.142 Panelization provides a variety of benefits. Erection of the enclosure can be faster and safer and done during inclement weather, and factory fabrication provides a higher level of quality control and tighter tolerances. PANEL ASSEMBLY COMPONENTS • Structural supporting frame: This is usually designed as a truss, • • • • • to span from column to column, and is fabricated from structural steel shapes and/or cold-formed metal framing. Sheathing: Galvanized steel sheets are used to help provide structural rigidity; gypsum sheathing is also common. Air barrier/vapor retarder: These are required when gypsum sheathing is used. Insulation: This is installed in the air space. Blanket insulation installed between the studs may be acceptable in some climates, but is not recommended. Rainscreen panel: Nearly all claddings that are used in drainage cavity or pressure-equalized wall assemblies are good candidates for panelization. These include brick, cast stone, and dimensional stone; aluminum composite material and plate architectural metal panels; formed metal panels; terracotta; resin-based panels; and EIFS. Interior finish: Normally, gypsum board is installed at the project site on furring or studs. INSULATED METAL PANEL WALL ASSEMBLIES Metal wall panels fall into two primary categories: field assembled and factory formed. Metal wall panels span between 4 and 15 ft (1.2 and 4.6 m), depending on the gauge of the metal, the panel thickness, and the wind load. The finish on metal panels can be raw galvanized sheet or any number of various factory-applied finishes, ranging from baked enamel to high-performance polyvinyldene fluoride (PVDF) coatings. RO OF WIND O WS AND SK YLIGHTS Skylights provide daylight to interior spaces and can reduce dependence on electrical lighting. In passive solar designs, skylights are used to admit direct solar radiation, thus enhancing space heating, and when vented properly, to induce convective airflow, reducing cooling loads through natural ventilation. Skylights are available as units (which are shipped to the site ready to be installed) or as framed assemblies of stock components (which arrive fabricated for site assembly). Both fixed and hinged skylights are manufactured. The hinged variety can be opened manually or by remote-control devices for venting. Frames are typically mounted on a built-up fabricated or site-built curb, with integral counterflashing; they can be assembled with or without insulation. Contributors: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. Eric K. Beach, Rippeteau Architects, PC, Washington, DC. Self-flashing skylight units are available with or without curbs. Those without curbs are intended only for pitched roof assemblies and are not recommended for roof assemblies with finished spaces below. Framed skylight assemblies are custom designed by manufacturers to meet the necessary wind, roof, and dead loads of the assembly itself. When a skylight is pitched beyond a certain angle, it must be designed to resist environmental factors, as does a curtain wall assembly. Roof drainage for rainwater and storm water can limit skylight dimensions. Many skylights are face sealed as a barrier system, but some are available as a pressure-equalized rainscreen system. In determining the desired form and size of the skylight unit/assembly, consideration should be given to: • Environmental conditions, including orientation and winter and summer solar penetration angles at the site • Prevailing wind direction and patterns • Precipitation quantity and patterns • Adjacent topography and landscaping (shade trees, etc.) • Coordination with the HVAC system • Use of shading, screening, or light-reflecting/bouncing devices • View desired relative to view obstructions, street lights 87 09_9780470889015_ch06.qxd:WILEY 88 9/19/11 10:24 AM Page 88 BUILD ING ST RU CT URE AND SHELL ROOF WINDOWS AND SK YLI G H T S FLAT-PANEL UNIT SKYLIGHT—SLOPED ROOF 6.143 FLAT-PANEL UNIT SKYLIGHT—SECTION 6.144 DOME UNIT SKYLIGHT—FLAT ROOF 6.145 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 89 INTERIOR CONSTRUCTION 7 FIRE-RESISTIVE CONSTRUCTION Building construction materials are tested for four criteria related to performance during a fire: • Fire resistance is the material’s ability to resist burning while retaining its structural integrity. • Flame spread measures the rate at which flames travel along the surface of a material. • Fuel contributed is a measure of how much combustible matter a material furnishes to a fire. • Smoke developed is a measure of the surface burning characteristics of a material. The fire-resistance rating is expressed in hours, determined by precisely conducted laboratory tests. When installed, each assembly must match the tested assembly. Many tests are proprietary, but the International Building Code (IBC) includes a series of generic assemblies with associated ratings. Several methods, both active (sprinklers) and passive, are possible for protecting building structures from fire. Designing for fire protection might include dividing a building into isolated modules with a limited number of penetrations for fire-rated doorways, electrical conduits, and ducts. Modules could be protected with sprayed fire-resistive materials, sprinklers, or both, depending on use, occupancy, potential exposure to abusive environments and individuals, and requirements of authorities having jurisdiction. FIRE-RETARDANT WOOD TREATMENT FIRE-RESISTANCE-RATED ASSEMBLIES Modern fire-retardant treatment (FRT) of wood consists of pressure treatment with aqueous solutions of various organic and inorganic chemicals, followed by kiln drying to reduce moisture content. A fire-resistance rating denotes the length of time a construction assembly can withstand fire and still serve as a barrier to fire and confine its spread to the area of origin. Fire spreads from one area to another when the barrier collapses, there are openings in the barrier, or sufficient heat is conducted through the barrier to exceed specified temperature limitations. The ratings are expressed in hours. Interior fire retardants meet Class I ratings, which are required by code for vertical exits and special areas. Class II ratings are required for horizontal exits, but this rating is rarely reached with untreated wood. Fire retardants come in interior and exterior types. Interior fire retardants are used on wood trusses and studs. Interior Type A wood is appropriate for interior and weather-protected applications with less than 95% relative humidity. FRT INTERIOR WOODWORK Instead of solid lumber, it is often desirable to build members of treated cores clad with untreated veneers 1/29 in. (0.08 mm) thick or less. Most codes discount this narrow finishing in determining the flame spread index of the wood, permitting the use of untreated wood in about 10% of the combined wall and ceiling surface area. FRT lumber and plywood can be lightly sanded for cosmetic cleaning after treatment. Painting and staining are possible but not always successful, particularly transparent finishes. Test finishes for compatibility before application. Fire-rated partitions with hourly ratings are identified in building codes for specific uses. Fire-resistance-rated partition types are as follows: • Nonrated: Includes ceiling-height (constructed from floor to ceiling) and full-height partitions (from floor to underside of structure above) not requiring a fire-resistance rating. Fullheight partitions may have gypsum board facing up to or extending above the ceiling or fully enclosing the full-height studs. • One hour: Separates different uses or occupancies, such as partitions between tenant spaces and public corridors in office buildings, or as indicated by building codes. One-hour partitions are used for smoke separation within a building. • Two hour: Encloses vertical openings within a building, including elevator and mechanical shafts, exit stairwells, and mechanical and electrical rooms. Two-hour partitions are used for fire separation and smoke or fire separation within a building. • Three hour: Separates and encloses higher-hazard areas. • Four hour: Encloses very high hazard spaces. 10_9780470889015_ch07.qxd:WILEY 90 9/19/11 10:32 AM I N T E R IO R CO NST RU CTION FULL-HEIGHT ONE-HOUR FIRE-RATED PARTITIONS Full-height one-hour fire-rated partitions are typically used to separate different occupancy types. ONE-HOUR FIRE-RATED FULL-HEIGHT PARTITION WITH ACOUSTICAL INSULATION 7.1 Page 90 FIRE-RESISTIVE CONSTRUCTION TWO-HOUR FIRE-RATED PARTITIONS Two-hour partitions are used at mechanical rooms, electrical closets, and other areas, as required by building codes. TWO-HOUR-RATED PRECAST CONCRETE JOISTS 7.4 TWO-HOUR FIRE-RATED FULL-HEIGHT PARTITION WITH TWO LAYERS OF GYPSUM BOARD 7.2 TWO-HOUR-RATED CEILING OR COLUMN 7.5 ONE-HOUR FIRE-RATED COLUMN 7.6 TWO-HOUR FIRE-RATED COLUMN 7.7 GYPSUM BOARD AT CEILINGS, BEAMS, AND SOFFITS TWO-HOUR-RATED OPEN-WEB STEEL JOIST 7.3 THREE-HOUR FIRE-RATED COLUMN 7.8 NOTES 7.1 a. The 3-3/4 in. (95 mm) partition type may not accommodate backto-back devices, such as junction boxes. b. Sound attenuation insulation provides improved acoustical properties with a Sound Transmission Class (STC) rating of 45. 7.2 a. Seal all joints, penetrations, and openings with fire-rated sealant when the assembly is used as a rated partition. b. Provide fire dampers where ducts penetrate partitions. c. Can be used as a nonrated partition when increased security and sound attenuation is desired. STC rating of 50 to 54. 7.3 1/2 in. (13 mm) Type X gypsum board or veneer base applied to gypsum board furring channels 24 in. (610 mm) on center (O.C.). 7.4 5/8 in. (16 mm) Type X gypsum board or veneer base screwattached to gypsum board furring channels 24 in. (610 mm) O.C. 7.5 a. Two layers of 5/8 in. (16 mm) Type X gypsum board or veneer base around beam. b. Outside corners of the face layer of gypsum board are protected by crimped or nailed steel corner beads, 0.020 in. (0.5 mm) thick. 7.6 a. 1/2 in. (13 mm) gypsum board or veneer base layer tied to column with 18-gauge wire 15 in. (380 mm) O.C. b. Face layer of 1/2 in. (13 mm) gypsum board or veneer base is applied with laminating compound over the entire contact surface. 7.7 a. Base layer of 1/2 in. (13 mm) gypsum board or veneer base fastened to 1-5/8-in. (41 mm) metal studs. b. Face layers of 1/2 in. (13 mm) Type X gypsum board or veneer base are attached to studs to provide a cavity between boards on the flange. c. Face layers across the web opening are laid flat across the base layer. 7.8 Three layers of 5/8 in. (16 mm) Type X gypsum board or veneer base screw-attached to 1-5/8 in. (41 mm) metal studs located at each corner. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 91 FIRE-RESISTIVE CONSTRUCTION FIRE-RESISTANCE-RATED OPENINGS DOOR OPENINGS FOR MEANS OF EGRESS 7.9 Fire-resistance-rated assemblies for openings, used to protect against the spread of fire and smoke, consist of a fire-rated door or window with frame, hardware, and accessories, including gasketing. Each component is crucial to the overall performance of the assembly as a fire barrier. Choices to be made regarding the enclosure of openings in fire-rated walls include: • Fire-resistance-rated wall requirements • Size of opening • Means of egress, including required size per occupancy, quantity and location, direction of egress flow and operation of enclosure, hardware requirements, and window egress requirements • Materials and finishes • Security • Visibility and glazing DEFINITIONS The terms defined here are commonly used in relation to fireresistance-rated openings: • Automatic: Providing a function without the necessity of human intervention. • Fire barrier: A continuous membrane, either vertical or horizontal (e.g., a wall, floor, or ceiling assembly), that is designed and constructed with a specified fire-resistance rating to limit the spread of fire and restrict the movement of smoke. • Fire-resistance rating: The time, in minutes or hours, that materials or assemblies have withstood fire exposure in accordance with the test procedure of NFPA 252. • Labeled: Equipment or materials marked with the label, symbol, or other identifying mark of an organization concerned with product evaluation and acceptable to the local jurisdiction. This organization must periodically inspect the production of labeled equipment. The manufacturer, by labeling the product, indicates compliance in a specified manner with appropriate standards or performance. • Noncombustible: A material that, in the form in which it is used and under the conditions anticipated, will not aid combustion or add appreciable heat to an ambient fire. • Self-closing: As applied to a fire door or other protective opening, means the door is normally closed and is equipped with an approved device that will ensure closure after the door has been opened. • Smoke barrier: A continuous membrane, either vertical or horizontal (e.g., a wall, floor, or ceiling assembly), that is designed and constructed to restrict the movement of smoke. A smoke barrier may or may not have a fire-resistance rating. FIRE PROTECTION CRITERIA NFPA 80, Standard for Fire Doors and Other Opening Protectives, establishes minimum criteria for installing and maintaining assemblies and devices used to protect openings in walls, ceilings, and floors from the spread of fire and smoke. Manufacturers of fire doors and window units locate metal labels in accessible, but concealed, locations—the hinge edge of doors, for example. These labels must remain in place, unpainted, uncovered, and unaltered. TYPES OF OPENINGS The hourly protection rating for openings depends on the use of the barriers—whether as exit enclosures, vertical openings in buildings, building separation walls, corridor walls, smoke barriers, or in hazardous locations. In most codes, class designations have been replaced by hour classifications such as the following: • 4-hour and 3-hour openings: Located in fire walls or in walls that divide a single building into fire areas. • 1-1/2-hour and 1-hour openings: Located in multistory vertical communication enclosures and in 2-hour-rated partitions providing horizontal fire separations. • 3/4-hour and 20-minute openings: Located in walls or partitions between rooms and corridors with a fire-resistance rating of one hour or less. FIRE-RESISTANCE-RATED STEEL FRAME ELEVATIONS 7.10 INTE R I O R CO N ST RU CT I O N WINDOW EGRESS REQUIREMENTS 7.11 91 10_9780470889015_ch07.qxd:WILEY 92 9/19/11 10:32 AM I N T E R IO R CO NST RU CTION FRAMES FOR FIRE-RESISTANCE-RATED OPENINGS 7.12 Page 92 FIRE-RESISTIVE CONSTRUCTION GLAZED OPENINGS Glazed openings in fire-resistance-rated walls must conform to size limitations meeting rated glass and other approved material requirements. Multiple panels are permitted, but the aggregate area of all panels and openings must not exceed 25% of the wall surface. Refer to specific codes for details. MAXIMUM DOOR SIZES 7.15 DOOR TYPE SIZES AND NOTES Single door 4-0 10-0 (1.2 3 m) with labeled single-point or three-point latching device Pair of doors 8-0 10-0 (2.4 3 m) active leaf with labeled single-point or three-point latching device 4-0 8-0 (1.2 2.4 m) with fire exit hardware GLAZED FIRE-RESISTANCE-RATED OPENING 7.14 8-0 10-0 (2.4 3 m) inactive leaf with labeled two-point latching device or top and bottom bolts 8-0 8-0 (2.4 2.4 m) with fire exit hardware SPRAY-APPLIED FIRE-RESISTIVE COATINGS Sprayed fire-resistive materials protect structural steel in both concealed and exposed applications. They include low-density cementitious and sprayed-fiber products, used predominantly for concealed locations, and a variety of medium- and high-density products, used for exposed locations that require a more finished appearance and greater resistance to physical abuse, air erosion, high humidity, and deterioration from weather, ultraviolet (UV) light, and chemical exposure. EXPOSED APPLICATIONS For exposed applications, sprayed fire-resistive materials are higher in density, compressive strength, bond strength, and hardness than those for concealed applications. Suggestions for high-density products include exposed interior areas protected by deluge sprinkler systems and areas subject to contact, physical abuse, high impact, chemical exposure, high humidity, air, and erosion. FIRE-RESISTANCE-RATED DOOR CLASSIFICATIONS 7.13 NOTE 7.15 Table lists maximum door sizes for hollow metal doors, all classes. Size requirements for wood doors are similar. Contributors: National Fire Protection Association, Quincy, Massachusetts. Daniel F. C. Hayes, AIA, Washington, DC. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 93 SEISMIC CONSIDERATIONS Examples of areas where denser sprayed fire-resistive materials might be considered are parking garages, loading docks, piers, cargo facilities, warehouses, manufacturing plants, mechanical rooms, elevator machine rooms, shafts, air-handling plenums, stairwells, cleanrooms, gymnasiums, and swimming pools. The following products are used for exposed applications: • • • • Exposed cementitious sprayed fire-resistive materials Exposed sprayed-fiber fire-resistive materials Foamed magnesium oxychloride fire-resistive materials Intumescent mastic fire-resistive coatings, including waterbased formulations, non-water-based formulations, and thin films Indoor air-quality issues related to sprayed fire-resistive materials include particulate inhalation, particulate eye and dermal irritation, volatile organic chemical (VOC) emissions and absorption, and contamination by biological agents. Sensitive environments may have stringent requirements for the control of particulate matter in indoor air, VOC emissions, and potential pathogens. The removal and replacement of sprayed fire-resistive materials can be a significant source of indoor air pollution. BOARD FIRE PROTECTION INTE R I O R CO N ST RU CT I O N WALL PENETRATION FIRESTOPS 7.16 Board fire protection includes calcium silicate and slag wool fiberboards, and is used for fire protection of steel columns, steel beams, metal- and wood-framed walls, and solid walls. These materials form the encasing material for various assemblies with fire-resistance ratings. Another use for mineral fiberboard fireproofing is the protection of HVAC ducts. The use of board protection instead of sprayed fire-resistive materials eliminates the cleanup of a wet residue and possible delays for drying that result from using sprayed material. Board fire protection is also less likely to corrode metal substrates. PENETRATION FIRESTOP SYSTEMS When selecting penetration firestop systems, the designer has to understand both what the local building code requires and how authorities having jurisdiction will interpret and enforce its provisions. Fire ratings required for each firestop system application are based on the analysis of building code requirements. If this analysis does not provide a clear answer, obtain interpretations of authorities having jurisdiction. S E I SM IC CO NSID E R ATIONS BASIC SEISMIC DESIGN PLATE TECTONICS According to the theory of plate tectonics, the earth’s crust is divided into constantly moving plates. Earthquakes occur when, as a result of slowly accumulating pressure, the ground slips abruptly along a geological fault plane on or near a plate boundary. The resulting waves of vibration within the earth create ground motions at the surface, which, in turn, induce movement within buildings. The frequency, magnitude, and duration of the ground motion, physical characteristics of the building, and geology of a site determine how these forces affect a building. In an earthquake, buildings designed to the minimum levels required by model codes often sustain damage. Early discussion with an owner should explore the need to limit property loss in an earthquake and the desirability of attempting to ensure continued building operation immediately afterward. To achieve these results, it may be necessary to make design decisions based on the seismic conditions of a site rather than on code requirements. SEISMIC CODES Seismic codes are confusing unless you are a civil or structural engineer. IBC Sections 1613 through 1623 provide the seismic requirements for each Seismic Category; reading the International Building Code Commentary will help architects and designers to really understand what it is saying. EARTHQUAKE TYPES In a minor earthquake, a structural site resists minor levels of earthquake ground motion with no structural damage and with only minor damage to nonstructural features, such as glazing, architectural finishes, and suspended ceilings. Such ground motion may occur many times during the economic life of a building and typically lasts only a few seconds. In a moderate-level earthquake, buildings resist moderate levels of earthquake ground motion with minor repairable structural damage and, possibly, some extensive nonstructural damage. Such ground motion could occur once or twice during the economic life of a building. The 1994 Northridge earthquake produced this level of ground motion throughout the Los Angeles area. In major earthquakes, buildings resist a level of earthquake ground motion that has an intensity equal to the strongest that has Contributors: Grace Construction Products, Cambridge, Massachusetts. either been experienced or forecast for the building site without collapse but possibly with some major structural as well as extensive nonstructural damage. Such ground motion may or may not occur during the economic life of a building. The 1906 San Francisco earthquake produced motions of this intensity throughout northern and central California. BASE SHEAR AND DRIFT 7.18 SEISMIC DESIGN LOAD PATH Load path refers to the path that seismic forces take from the roof to the foundation of a structure. Typically, the load travels from the diaphragms through connections to the vertical lateral force–resisting elements and on to the foundation by way of additional connections. This path should be direct and uninterrupted. Seismic design begins with, and codes require, the establishment of a continuous load path. LIFE SAFETY The intent of the seismic design provisions of the IBC is to prevent injuries and loss of life, not to minimize property damage. These minimum criteria are considered to be prudent and economically justified for the protection of life safety. BASE ISOLATION 7.17 SHEAR WALLS AND DIAPHRAGM 7.19 93 10_9780470889015_ch07.qxd:WILEY 94 9/19/11 10:32 AM I N T E R IO R CO NST RU CTION FORCE DIAGRAMS 7.20 Page 94 SEISMIC CONSIDERATIONS SEISMIC LOAD TRANSFER 7.24 FLOOR AND ROOF DIAPHRAGM 7.25 GROUND RUPTURE 7.21 WALL SECTION FOR CONVENTIONAL WOOD FRAMING 7.26 FLOOR AND ROOF DIAPHRAGM GROUND SHAKING 7.22 LIQUEFACTION 7.23 SEISMIC DETAILING FOR DESIGNERS When detailing architectural and mechanical elements for seismic resistance, the designer’s primary concerns are to minimize falling hazards and to maintain a normal egress route. Features such as masonry chimneys, parapets, light fixtures, suspended mechanical equipment, large ductwork, and heavy pipes are potential falling hazards. Cabinets and bookcases can block exits if they fall. An additional concern for designers working with sites in earthquakeprone areas is the need for a building to remain in operation after an earthquake. SEISMIC LOAD TRANSFER Each diaphragm in a building must resist the seismic effects in both directions of all the mass above it, as well as of its own mass. The seismic loads caused by the roof mass must be transferred to the wall, and the wall must be designed to resist both the effect of the mass of the roof and the mass of the wall. These combined loads must then be transferred to the floor below, which must be designed to resist the effect of both its mass and the load applied by the wall above. In turn, walls below must resist these loads, until the force reaches the foundation, which must be able to resist the combined loads from the rest of the building. Contributors: Jane Clark, AIA, Zimmer Gunsul Frasca Partnership, Seattle, Washington. Dan Fenton, PE, EQE International, Seattle, Washington. Diaphragms—the roof, floor(s), and shear panels in walls—must be designed to resist forces created by the dead-load mass of the structure and applied seismic loads. In wood frame construction, a diaphragm is typically a structural panel made of a skin (sheathing) stretched over and fastened to ribs (wood members such as 2 4s). The resulting construction is stiff and strong enough to transmit forces to resisting systems such as the foundation. Connections must be designed to transfer lateral forces and restrain overturning motion. Lateral forces can be either perpendicular or parallel to the structure. The load from each part of a building that it creates as the building shifts from the movement of the earth must be transferred to adjoining elements—roof sheathing to rafters to top plates to wall sheathing, and studs to bottom plates to floor sheathing and framing, and so on—until the lowest level of floor framing, from which the load moves to the foundation. In slab-on-grade construction, the load moves finally from the wall sheathing and studs to the bottom plates. The roof diaphragm comprises roof sheathing, roof framing (rafters, top chord of truss, etc.), and blocking. The ceiling diaphragm comprises ceiling finish material (e.g., gypsum wallboard) and ceiling framing (joists, lower chord of trusses, etc.). Roof-to-wall anchorage consists of hold-down anchors to resist uplift forces and nailing to resist shear forces. The wall diaphragm comprises wall sheathing, wall framing, and sheathing fasteners. The floor diaphragm comprises floor sheathing, floor framing (joists, trusses, etc.), blocking, and so on. Wall-to-floor anchorage consists of hold-down anchors and shear connectors (e.g., nails). Floor-to-foundation anchorage consists of hold-down anchors to resist overturning forces and anchor bolts 1/2 in. (13 mm) in diameter at 6 ft (1.8 m) to resist shear forces. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 95 INT E R IO R CONSTRUCTION COMPONENTS WOOD WALL SHEAR PANEL Shear panels that consist of framing members and sheathing panel(s) or diagonal sheathing members provide the principal lateral resistance to shear loads. WOOD WALL SHEAR PANEL 7.27 INTE R I O R CO N ST RU CT I O N BRACED WALL SPACING 7.28 Sheathing panels are made of plywood or oriented strand board (OSB) for structural panels, gypsum sheathing, or fiberboard. Diagonal wood sheathing boards or strapping can also be used. I N T E R IO R CO NST RU CTION COMPONENTS GYPSUM BOARD ASSEMBLIES Gypsum board assemblies are composed of gypsum board panels and the wood or metal support systems to which they are attached. These systems include structural and nonstructural interior partitions and ceiling assemblies. Critical factors in the design of gypsum board assemblies include the following: • Fire resistance: Ability of a wall to serve as a barrier to flame, smoke, and/or heat • Acoustics: Ability to attenuate or absorb sound • Moisture resistance: Ability to avoid damage from moisture or mold • Abuse resistance: Sturdier materials will require less maintenance and repair • Aesthetics: Ability to emphasize details and finishes • Sustainability: Use of recycled and renewable raw materials Gypsum board is typically installed by screwing (and sometimes nailing or stapling) it to studs or furring channels. It can also be directly glued to masonry or concrete. Contributors: Jane Clark, AIA, Zimmer Gunsul Frasca Partnership, Seattle, Washington. Dan Fenton, PE, EQE International, Seattle, Washington. David S. Collins, FAIA, American Forest and Paper, Cincinnati, Ohio. CMU WALL WITH PLUMBING CHASE AND METAL STUD PARTITION 7.29 METAL STUD PARTITION 7.30 95 10_9780470889015_ch07.qxd:WILEY 96 9/19/11 10:32 AM I N T E R IO R CO NST RU CTION WOOD STUD PARTITION 7.31 Page 96 INTERIOR CONSTRUCTION CO MPO N E N T S DOUBLE-STUD PLUMBING CHASE 7.33 GYPSUM BOARD Gypsum board (also called sheet rock or gyp board ) is the generic name for a family of sheet products consisting of a noncombustible gypsum core faced with a paper surface. Certain gypsum board assemblies provide fire resistance and sound transmission reduction of varying degrees. Gypsum board may be finished with paint or other applied finish materials, such as a wallcovering, wood, or tile. Mold and moisture dynamics has grown as an increasingly important design and specification concern with materials that have absorptive characteristics and are prone to mold and mildew problems. Gypsum board must be properly installed, finished, and provided with adequately designed and operated climate control systems to avoid these problems. The North American gypsum industry has developed a responsible and environmentally conscious attitude toward issues of reclamation, preservation of natural resources, recycling and waste management, and otherwise protecting the environment. Over 90% of the gypsum board paper used comes from recycled materials. The industry increasingly uses synthetic gypsum to manufacture gypsum board. This raw material is a by-product, or waste, from other manufacturing processes as well as the desulfurization of flue gases in fossil fuel power plants. GYPSUM BOARD TYPES A number of specialized gypsum panel products and gypsum boards have been developed for specific uses, including: CMU WALL WITH METAL HAT CHANNEL FURRING 7.32 CONCRETE WALL WITH METAL HAT CHANNEL FURRING 7.34 • Gypsum wallboard for interior walls and ceilings • Gypsum ceiling board for interior ceilings, 1/2 in. (12.7 mm) thick, with a sag resistance equal to 5/8-in. (15.9 mm) wallboard • Type X gypsum board for fire-resistance-rated building systems • Fiber-reinforced gypsum panels for interior and exterior walls, ceilings, and tile base • Gypsum sheathing for exterior walls and roof systems • Glass mat gypsum substrate for use as sheathing on exterior walls and ceilings • Gypsum soffit board for use on exterior soffits and ceilings • Water-resistant gypsum backing board (green board ) for use as a tile base and in wet areas (contingent on building code restrictions) where wetting is intermittent • Glass mat water-resistant gypsum backing board for use as a tile base and in wet areas (contingent on building code restrictions) and where moisture and direct water flow are present • Gypsum backing board for use as a base for multi-ply systems • Gypsum lath for use as a base for gypsum plaster; available in 16-in. (406-mm) widths • Gypsum plaster base (blue board ) for use as a base for veneer plaster • Gypsum shaft liner board for shaft, stairway, and duct enclosures • Predecorated gypsum board for accent walls, offices, and movable partitions • Foil-backed gypsum board for use as a vapor retarder • Gypsum fiber underlayment for use in residential floor construction • Fiber-reinforced panel, 1/4 to 3/8 in. (6 to 9 mm) thick 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 97 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N TYPICAL BOARD USES AND SIZES 7.35 THICKNESS TYPICAL USES WIDTH LENGTHS 1/4 (6.4 mm) Remodeling, double-layer walls, curved surfaces, sound attenuation 48 (1,220 mm) 8-0, 9-0, 10-0 (2,440, 2,745, 3,050 mm) 5/16 (7.9 mm) Manufactured housing walls and ceilings 48 (1,220 mm) 8-0, 9-0, 10-0, 12-0 (2,440, 2,745, 3,050, 3,660 mm) 3/8 (9.5 mm) Remodeling, base for rigid panels, double-layer walls and ceilings, curved surfaces 48 (1,220 mm) 8-0, 9-0, 10-0 (2,440, 2,745, 3,050 mm) 1/2 (12.7 mm) Any interior and some protected exterior uses 48 (1,220 mm) 12-0 (3,660) also available 54 (1,370 mm) 8-0, 9-0, 10-0, 12-0, 14-0, 16-0 (2,440, 2,745, 3,050, 3,660, 4,270, 4,880 mm) 5/8 (15.9 mm) Any interior and some protected exterior uses 48 (1,220 mm) 12-0 (3,660) also available 54 (1,370 mm) 8-0, 9-0, 10-0, 12-0, 14-0, 16-0 (2,440, 2,745, 3,050, 3,660, 4,270, 4,880 mm) 3/4 (19.0 mm) Interior walls, shaft walls, area separation walls, party walls, fire walls, stairways, duct enclosures 24, 48 (610, 1,220 mm) 8-0, 9-0, 10-0, 12-0 (2,440, 2,745, 3,050, 3,660 mm) 1 (25.4 mm) Interior walls, shaft walls, area separation walls, party walls, fire walls, stairways, duct enclosures 24 (610 mm) 8-0, 9-0, 10-0, 12-0 (2,440, 2,745, 3,050, 3,660 mm) TYPES OF EDGES Gypsum board sheets come in a variety of edge types. These include: • • • • • • Square Tapered Rounded tapered Beveled Double beveled “V” tongue and groove GYPSUM BOARD BEAD AND TRIM ACCESSORIES PAPER-FACED METAL BEAD AND TRIM Paper-faced metal bead and trim is applied using setting-type, taping, or all-purpose joint compound instead of nails to bond the bead to gypsum panel surfaces. PAPER-FACED METAL GYPSUM BOARD ACCESSORIES 7.37 GYPSUM BOARD EDGE TYPES 7.36 TYPE Outside corner tape-on bead USE 90° outside corners DESCRIPTION Any wallboard thickness Inside corner tape-on trim True 90° inside corner Any wallboard thickness Offset outside corner tape-on bead 135° outside corners Any wallboard thickness; smaller bead height for less joint compound fill Offset inside corner tape-on bead Inside corners greater than 90° Any wallboard thickness 3/4 (19 mm) bullnose outside corner tape-on bead Rounded 3/4 (19 mm) radius, 90° corner angle Gypsum panels 1/2 or 5/8 (6 or 16 mm) thick Inner cove tape-on trim Rounded 3/4 (19 mm) radius, 90° inside corner Gypsum panels 1/2 or 5/8 (6 or 16 mm) thick Bullnose offset outside corner tape-on bead Rounded 135° offset outside corner Used for bay windows and similar applications Offset inner cove tape-on trim 135° inside corners Forms smooth cove 1-1/2 (38 mm) bullnose outside corner (Danish) tape-on bead Broader, gentler corner than 3/4 (19 mm) radius bullnose Gypsum panels 1/2 or 5/8 (6 or 16 mm) thick Corner reinforcing tape Flexible tape for straight, sharp corners at any angle Cathedral and drop ceilings, arches, around bay windows; also used to join drywall partition to plastered wall in remodeling, and for repairing chipped and cracked corners L-shaped tape-on trim Used where wallboard abuts other surfaces Joints at suspended ceilings, beams, plaster, masonry and concrete walls; also untrimmed door and window jambs J-shaped tape-on trim Used to finish rough gypsum board panel ends Used at window and door openings and casements Outside corner microbead Reduced height results in less joint compound consumption Extra-wide flanges for maximum corner coverage Reveal tape-on trim Solves problems with reveals on soffits, wall offsets, ceilings, light boxes, other architectural features Paper flange on both trim legs eliminates need to caulk edge of reveal details, provides cleaner, straighter line 97 10_9780470889015_ch07.qxd:WILEY 98 9/19/11 10:32 AM I N T E R IO R CO NST RU CTION Page 98 INTERIOR CONSTRUCTION CO MPO N E N T S METAL TRIM CORNER TAPES 7.38 Metal trim is applied similarly to metal bead and provides protection and neat finished edges to gypsum panels. Consult manufacturer’s literature for proper use and installation. METAL TRIM FOR VENEER PLASTER AT CASED OPENINGS 7.41 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 214, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. METAL TRIM FOR VENEER PLASTER AT CEILING INTERSECTIONS 7.42 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 26, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. A variety of metal and plastic framing and furring accessories are available, including: METAL BEAD Metal bead is screwed, nailed, stapled, or attached with a clinchon tool to framing through the panels and concealed with joint compound. The exposed nose of the bead helps prevent outside corner damage from impact and provides a screed for finishing. Consult manufacturer’s literature for proper use and installation. EXPANDED FLANGE CORNER BEAD 7.40 GALVANIZED STEEL REINFORCEMENT EXTERNAL CORNER PROTECTION 7.39 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 25, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 24, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. • Metal angles are made of 24-gauge galvanized steel and are used to secure 1-in. (25-mm) core board or liner panels at floor and ceiling in laminated gypsum board partitions. • Cold-rolled channels are made of 16-gauge steel and are used in furred walls and suspended ceilings. • Z-furring channels are made of 24-gauge steel and are used to mechanically fasten insulation blankets, rigid insulation, and gypsum board panels to concrete or masonry walls. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 99 INT E R IO R CONSTRUCTION COMPONENTS GYPSUM BOARD ACCESSORIES 7.43 FRAMING AND FURRING ACCESSORIES • Metal angles: Used to secure 1-in. (25-mm) core board or liner at floor and ceiling • Cold-rolled channels: Used in furred walls and suspended ceilings • Resilient channel: Used for reducing sound transmission through partitions and ceilings • Z-furring: Used to mechanically attach insulation and gypsum panels to interior side of concrete and masonry walls • Metal furring channels: Hat-shaped sections used for screw attachment of gypsum panels in walls and ceilings INTE R I O R CO N ST RU CT I O N • Furring channel clips: Used in attaching metal furring channels to cold-rolled channels • Adjustable wall furring brackets: Used for attaching cold-rolled channels and metal furring channels to interior side of exterior masonry walls REINFORCING TAPES Joint tape is for use with joint compounds in the reinforcement and concealment of flat joints and inside corners. It is approximately 2 to 2-1/2 in. (51 to 64 mm) wide and comes in various roll lengths ranging from 75 to 500 ft (23 to 152 m). There are generally two types of products: FRAMING AND FURRING ACCESSORIES 7.45 CONTROL JOINTS Control joints are typically stapled to the panel face. Made from roll-formed zinc, they are used to minimize (not eliminate) cracking induced by expansion and contraction in large ceiling and wall expanses in drywall and veneer plaster systems. Where fire and sound control are prime considerations, a seal must be provided behind the control joint. Control joints are deliberately created lines of weakness along which cracking will occur. Control joints alleviate the stress that would otherwise cause random cracking, by providing a control pattern of straight lines. Control joints should be installed where indicated on the plans or specifications, typically at geometric discontinuities, such as corners, changes in the height or width of a surface, openings, and large uninterrupted surfaces. CONTROL JOINT 7.44 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 216, Control Joint No. 093, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 33, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. • Paper tape for treatment with joint compounds is designed for both embedding by hand and application with a mechanical taping tool; joint is covered with a thin layer of compound before taping. • Glass fiber tape for veneer plaster finishes comes with a pressure-sensitive adhesive backing or plain back for fastening with staples. Typically used when one-day joint finishing is required. 99 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 100 I N T E R IO R CO NST RU CTION JOINT TAPING TOOLS 7.46 Page 100 INTERIOR CONSTRUCTION CO MPO N E N T S JOINT TAPES 7.47 FINISHES Gypsum board panels are finished using reinforcing tapes and gypsum board taping, topping, or all-purpose compounds. Products are available in site-mixed or ready-mixed formulations. Taping compounds are designed for embedding tape. They have excellent bond and crack resistance but are harder to sand and finish than topping or all-purpose compounds. All-purpose joint compounds are good for taping, topping, and repairing cracks. They perform with versatility for use as tape, finish, texture, laminate, or skim coat applications. Topping compounds, which have low shrinkage and are easy to apply and sand, are most suitable for second- and third-coat applications. FRAMING GENERAL REQUIREMENTS Gypsum board is applied over wood or steel framing or furring. The quality of the application is largely dependent on the accurate alignment of the framing or furring to which the gypsum board is attached. WOOD FRAMING Wood stud partitions are suitable for residential and light-commercial construction where combustible framing is permitted by code. These designs include single- and double-layer gypsum board facings, single- and double-row studs, those with insulating blankets, and those with resilient attachments. Performance values up to two-hour fire resistance and an STC of 58 can be obtained. The choice and installation of framing depends on a number of factors. In the case of wood framing, these include the species, size, and grade of lumber used. Equally important are the height of the wall, the frame spacing, and the maximum span of the surfacing material. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 54, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 52, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Contributor: Del Shuford, AIA, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 101 INT E R IO R CONSTRUCTION COMPONENTS STEEL STUD FRAMING MAXIMUM FRAME SPACING—GYPSUM BOARD CONSTRUCTION, DIRECT APPLICATION 7.48 APPLICATION Single layer Parallel 16 (406 mm) Steel stud partitions are suitable for all types of construction. Designs include single- and multilayer gypsum board facings, single- and double-row studs, those with sound attenuation or fire blankets, and those with resilient attachments. Performance values up to four-hour fire resistance and an STC of 65 can be obtained. Perpendicular 24 (610 mm) Steel studs are typically manufactured in two different styles: Parallel 16 (406 mm) Side walls Parallel or perpendicular 24 (610 mm) Parallel 16 (406 mm) 5/8 (15.9 mm) Ceilings Perpendicular 24 (610 mm) Side walls Parallel or perpendicular 24 (610 mm) 3/8 (9.5 mm) Ceilings Perpendicular 16 (406 mm) Side walls Parallel or perpendicular 24 (610 mm) • Studs designed for non-load-bearing interior drywall partition applications have a minimum 1-1/4 in. (31 mm) flange width on both sides. The web design incorporates a cutout for bracing and for electrical, communications, and plumbing lines. • Studs designed for load-bearing drywall partition applications have a 1-5/8 in. (41 mm) flange width on both sides. Cutouts in the web accommodate bracing, utility service, and mechanical attachments. 1/2 and 5/8 (12.7 and 15.9 mm) Ceilings Parallel or perpendicular 24 (610 mm) Side walls Perpendicular See Note g. PANEL THICKNESS 3/8 (9.5 mm) 1/2 (12.7 mm) Double layer INTE R I O R CO N ST RU CT I O N 101 LOCATION Ceilings APPLICATION METHOD Perpendicular Ceilings MAXIMUM FRAME SPACING O.C. 16 (406 mm) Consult manufacturer’s literature for proper use and installation STEEL STUD 7.50 WOOD FRAME, FIRE-RATED WALL SECTIONS 7.49 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 27, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. STEEL RUNNER 7.51 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 27, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. NOTES 7.48 a. Panel thickness: •5/8 in. (15.9 mm) thickness is recommended for the finest single-layer construction, providing increased resistance to fire and transmission of sound. •1/2 in. (127 mm) thickness is recommended for single-layer application in new residential construction and remodeling. •3/8 in. (9.5 mm) thickness is recommended for repair and remodeling over existing surfaces. b. If fire rating is required, maximum frame spacing 16 in. (406 mm) O.C. for doublelayer: •3/8 in. (9.5 mm) perpendicular or parallel side walls •1/2 in. (12.7 mm) and 5/8 in. (15.9 mm) perpendicular side walls •1/2 in. (12.7 mm) and 5/8 in. (15.9 mm) perpendicular or parallel ceilings 7.49 a. STC range 35 to 39. b. STC range 45 to 49. c. STC range 55 to 59. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 102 I N T E R IO R CO NST RU CTION Page 102 INTERIOR CONSTRUCTION CO MPO N E N T S INTERIOR FRAMING LIMITING HEIGHTS 7.52 STUD DEPTH PRODUCT IDENTIFICATION STUD SPACING 1-5/8 (41 mm) (162S125-18/33) 24 (610 mm) 16 (406 mm) 2-1/2 (64 mm) (250S125-18/33) 24 (610 mm) 16 (406 mm) 3-5/8 (92 mm) (362S125-18/33) 24 (610 mm) 16 (406 mm) 4 (102 mm) (400S125-18/33) 24 (610 mm) 16 (406 mm) 6 (152 mm) (600S125-18/33) 24 (610 mm) 16 (406 mm) CEILINGS—EXTERIOR WALL INTERSECTION 7.55 DESIGN LIMIT 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) 5 psf (24.4 kg/m) ALLOWABLE DEFLECTION 25 GAUGE MINIMUM 20 GAUGE MINIMUM L/120 9-9 (2,970 mm) 11-0 (3,350 mm) L/240 7-11 (2,410 mm) 8-9 (2,670 mm) L/360 7-1 (2,160 mm) 7-8 (2,030 mm) L/120 10-7 (3,230 mm) 12-1 (3,680 mm) L/240 8-4 (2,540 mm) 9-8 (2,950 mm) L/360 8-2 (2,490 mm) 8-5 (2,570 mm) L/120 11-10 (3,610 mm) 14-10 (4,520 mm) L/240 10-7 (3,230 mm) 11-7 (3,530 mm) L/360 9-3 (2,820 mm) 10-0 (3,050 mm) L/120 13-3 (4,040 mm) 16-5 (5,000 mm) L/240 11-3 (3,430 mm) 12-10 (3,910 mm) L/360 9-10 (3,000 mm) 11-2 (3,400 mm) L/120 13-9 (4,190 mm) 18-6 (5,640 mm) L/240 13-5 (4,090 mm) 14-9 (4,500 mm) L/360 11-7 (3,530 mm) 12-9 (3,890 mm) L/120 15-4 (4,670 mm) 20-8 (6,300 mm) L/240 14-4 (4,370 mm) 16-5 (5,000 mm) L/360 12-4 (3,760 mm) 14-3 (4,340 mm) L/120 15-1 (4,600 mm) 20-9 (6,330 mm) L/240 14-2 (4,320 mm) 16-5 (5,000 mm) L/360 12-4 (3,760 mm) 14-3 (4,340 mm) L/120 17-2 (5,230 mm) 23-1 (7,040 mm) L/240 15-4 (4,670 mm) 18-4 (5,590 mm) L/360 13-4 (4,060 mm) 15-11 (4,850 mm) L/120 16-9 (5,110 mm) 27-2 (8,280 mm) L/240 16-9 (5,110 mm) 21-7 (6,580 mm) L/360 16-9 (5,110 mm) 18-10 (5,740 mm) L/120 19-9 (6,020 mm) 30-10 (9,400 mm) L/240 19-9 (6,020 mm) 24-6 (7,470 mm) L/360 17-11 (5,770 mm) 21-4 (6,500 mm) Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 133, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. STEEL STUD FRAMING SYSTEM 7.56 Source: Adapted from USG Gypsum Construction Handbook, 6th ed., p. 27, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Copyrighted work of USG Corporation. STEEL STUD FRAMING 7.53 METAL FURRING CHANNEL 7.54 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 84, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Suspension system framing is a pre-engineered alternative to traditional framing for flat or curved drywall ceilings and soffits. These grid systems are composed of a selection of main and cross tees that can be used for a variety of suspended ceiling applications. These systems include labor-saving accessories that reduce hanger wire and speed design details such as control joints, light fixtures, and utility framing. The hot-dipped, galvanized steel system is suitable for direct screw attachment of gypsum panels at interior and exterior locations. Source: Copyrighted work of USG Corporation, USG SA923, Gypsum Board/Steel Framed Systems. Drywall barrel vaults, archways, valleys, waves, serpentines, and domes all have the flexibility to easily transition to flat ceilings, soffits, and acoustical ceiling suspension systems. All main tees (straight and curved) can be easily field cut to specific lengths. CEILING FRAMING Suspended drywall and plaster ceilings can be framed with conventional framing materials or with a drywall suspension system. The system includes Underwriters Laboratories (UL) fire-rated designs with design flexibility to meet life safety codes and load compliance specifications. Metal framing typically includes the use of a carrying channel and furring or hat channel suspended by 8- or 9-gauge hanger wire. Steel stud framing typically includes the use of metal studs suspended by 8- or 9-gauge hanger wire. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 82, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. NOTES 7.52 a. The industry-wide product identification, created by the Steel Stud Manufacturers Association (SSMA), identifies the member depth, style, flange width, and material thickness in mils. b. Limiting-heights data is from ASTM C 754. c. Limiting heights apply to walls constructed with a minimum 1/2-in. (12.7-mm) thickness of gypsum board and with a minimum of one fullheight layer on both sides of the stud framing. d. 25 gauge is equal to 18 mils, 0.01799 in., or 0.455 mm; 20 gauge is equal to 33 mils, 0.03299 in., or 0.836 mm. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 103 INT E R IO R CONSTRUCTION COMPONENTS DRYWALL SUSPENSION SYSTEM WITH CROSS TEE 7.57 Source: Copyrighted work of USG Corporation, USG Installation and Application Guides, Drywall Suspension Systems Users Guide AC3157, p. 11. FLAT CEILINGS 7.58 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 79, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. INTE R I O R CO N ST RU CT I O N 103 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 104 I N T E R IO R CO NST RU CTION Page 104 INTERIOR CONSTRUCTION CO MPO N E N T S CURVED CEILINGS 7.59 GYPSUM BOARD ASSEMBLY DESIGN CONSIDERATIONS FIRE PROTECTION Fire resistance refers to the ability of a wall, floor, or ceiling system to serve as a barrier to flame and confine it to the originating area. A fire-resistance rating denotes the length of time a given assembly has withstood fire in controlled laboratory conditions, according to ASTM procedures, without collapsing. Partition assemblies must be able to remain standing and contain or slow the spread of flame, smoke, and heat for a sufficient length of time so that occupants are able to evacuate the building. Fire-rated partitions with hourly ratings are identified in building codes for specific uses. The UL Fire Resistance Directory and other publications are referenced for fire-resistance ratings. TYPICAL FIRE-RESISTANCE PARTITION TYPES Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 80, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. SOFFITS ON CEILINGS 7.60 • Nonrated: Includes ceiling-height (floor to ceiling) and fullheight (floor to underside of structure above) not requiring a fire-resistance rating. Full-height partitions may have gypsum board applied up to the ceiling, extending slightly above the ceiling, or extending to the underside of the structure above. • One hour: Separates different occupancies or uses, such as partitions between tenant spaces and public corridors in office buildings, or as required by building codes. • Two hour: Encloses vertical openings within a building, including elevator and mechanical shafts, exit stairwells, and mechanical/electrical rooms, or as required by building codes. • Three hour: Separates and encloses high-hazard uses/areas or as required by building codes. • Four hour: Separates and encloses very high hazard uses/areas or as required by building codes. CEILING-HEIGHT PARTITION 7.61 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 80, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Contributor: Del Shuford, AIA, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 105 INT E R IO R CONSTRUCTION COMPONENTS FULL-HEIGHT STUD PARTITION 7.62 ONE-HOUR STEEL STUD WITH CONTROL JOINT 7.64 INTE R I O R CO N ST RU CT I O N 105 TWO-HOUR PARTITION 7.67 Source: Copyrighted work of USG Corporation, USG Publication SA 100/rev. 10-04, Fire Assemblies, p. 71. TWO-HOUR STEEL STUDS WITH CONTROL JOINTS 7.65 Source: Copyrighted work of USG Corporation, USG Publication SA 100/rev. 10-04, Fire Assemblies, pp. 68–69. ONE-HOUR FIRE-RESISTIVE CONTROL JOINT 7.68 CEILING AND FLOOR ATTACHMENTS 7.63 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 173, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. ONE-HOUR PARTITION 7.66 Source: Copyrighted work of USG Corporation, USG Publication SA 100/rev. 10-04, Fire Assemblies, pp. 68–69. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 192, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Source: Copyrighted work of USG Corporation, USG Publication SA 100/rev. 10-04, Fire Assemblies, pp. 68–69. NOTE 7.62 This nonrated partition is used with ceilings installed within the partitioned space. Full-height metal studs provide a stable partition. Consult manufacturer’s literature for information on allowable heights and transverse loading (e.g., shelving). The STC rating is 35. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 106 I N T E R IO R CO NST RU CTION Page 106 INTERIOR CONSTRUCTION CO MPO N E N T S ONE-HOUR-RATED METAL ASSEMBLIES 7.69 FIGURE FIRE TEST NO. RATING (HOURS) SYSTEM THICKNESS STC UL Des U419 or U465 1 4-7/8 (124 mm) 40 49 51 UL Des U419 or U448 UL Des U419 or U448 1 1 3-1/2 (89 mm) 47 3-3/4 (95 mm) 4-7/8 (124 mm) 45 48 4 (102 mm) 50 41 DESCRIPTION 5/8 (15.9 mm) Type X gypsum panels Panels applied vertically or horizontally. Horizontal joints need not be staggered or backed by framing. 3-5/8 (93 mm) 25-gauge steel studs 24 (610 mm) O.C. Joints finished Optional veneer plaster Based on 3 (76 mm) sound attenuation fire batt (SAFB) Based on 5/8 (15.9 mm) Type C gypsum panels and 3 25 (76 635 mm) SAFB creased to fit cavity 1/2 (12.7 mm) Type C gypsum panels 2-1/2 (64 mm) 25-gauge studs 24 (610 mm) O.C. 1-1/2 (38 mm) Thermafiber SAFB Joints finished Based on 5/8 (15.9 mm) Type X panels, 2 (51 mm) mineral wool batts, horizontal joints directly opposite and finished Based on 5/8 (15.9 mm) Type X panels, 3-5/8 (93 mm) studs, 2 (51 mm) mineral wool batts, horizontal joints directly opposite and finished 1/2 (12.7 mm) Type C gypsum panels Panels applied vertically or horizontally. Horizontal joints need not be staggered or backed by framing. 2-1/2 (64 mm) 25-gauge steel studs 24 (610 mm) O.C. 1-1/2 (38 mm) Thermafiber SAFB Joints finished Based on NO Thermafiber SAFB TWO-HOUR-RATED METAL ASSEMBLIES 7.70 FIGURE FIRE TEST NO. RATING (HOURS) SYSTEM THICKNESS STC UL Des U419 or U412 2 3-5/8 (92 mm) NA 2 5-5/8 (143 mm) 4-1/2 (115 mm) 5-5/8 (143 mm) 4-1/8 (105 mm) 50 54 55 NA 2 6-1/8 (155 mm) 6-1/8 (155 mm) 5 (127 mm) 5-5/8 (143 mm) 48 56 56 NA 8-3/8 (213 mm) 8 (203 mm) 59 60 UL Des U419 or U411 UL Des U419 or U453 DESCRIPTION 1/2 (12.7 mm) Type C gypsum panels 1-5/8 (41 mm) 25-gauge steel studs 24 (610 mm) O.C. Double-layer gypsum panels screw attached to channel, two layers screw attached to steel studs Face layer joints finished Optional veneer plaster Based on 3-5/8 (92 mm) studs Based on 2-1/2 (64 mm) studs, 1-1/2 (38 mm) mineral wool batts Based on 3-5/8 (92 mm) studs, 1-1/2 (38 mm) mineral wool batts 5/8 (15.9 mm) Type X gypsum panels 1-5/8 (41 mm) 25-gauge steel studs 24 (610 mm) O.C. Double-layer gypsum panels screw attached to channel, two layers screw attached to steel studs Face layer joints finished Optional veneer plaster Based on 5/8 (15.9 mm) Type C panels, 3-5/8 (92 mm) studs Based on 3-5/8 (92 mm) studs, 3 (76 mm) mineral wool batts Based on 2-1/2 (64 mm) studs, 2 mineral wool batts 1/2 (12.7 mm) Type C gypsum panels 3-5/8 (92 mm) 20-gauge studs 24 (610 mm) O.C. 3 (76 mm) Thermafiber SAFB RC-1 channel or equivalent one side, spaced 24 (610 mm) O.C. Double-layer gypsum panels screw attached to channel, one layer screw attached to steel studs Face layer joints finished Optional veneer plaster Based on 5/8 (15.9 mm) Type X panels, 6 (152 mm) 20-gauge structural studs, 5 (127 mm) mineral wool batts Based on 1/2 (12.7 mm) panels, 6 (152 mm) 20-gauge structural studs, 5 (127 mm) mineral wool batts THREE- AND FOUR-HOUR-RATED METAL ASSEMBLIES 7.71 FIGURE FIRE TEST NO. RATING (HOURS) SYSTEM THICKNESS STC UL Des U419 or U455 3 6-5/8 (168 mm) NA UL Des U419 or U435 3 DESCRIPTION 1/2 (12.7 mm) Type C gypsum panels 3-5/8 (92 mm) 20-gauge studs 24 (610 mm) O.C. RC-1 channel or equivalent side, spaced 24 (610 mm) O.C. Face layer joints finished 7-1/4 (184 mm) 62 Based on 5/8 (15.9 mm) Type X panels 9 (229 mm) 64 Based 6 (152 mm) 20-gauge structural studs, 5 (127 mm) Thermafiber SAFB 9-5/8 (245 mm) 65 Based on 5/8 (15.9 mm) Type X panels, 6 (152 mm) 20-gauge structural studs, 5 (127 mm) Thermafiber SAFB, acoustical sealant bead between panels and studs, dabs 8 (203 mm) O.C. between panel layers and stud side 4-5/8 (118 mm) 59 1/2 (12.7 mm) Type C gypsum panels 1-5/8 (41 mm) 25-gauge steel studs 24 (610 mm) O.C. 1-1/2 (38 mm) mineral wool batt Optional veneer plaster 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 107 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 107 ONE-HOUR-RATED WOOD ASSEMBLIES 7.72 FIGURE FIRE TEST NO. RATING (HOURS) SYSTEM THICKNESS STC UL Des U327 1 5-1/4 (133 mm) 50 5/8 (15.9 mm) Type C gypsum panels 2 4 wood stud 16 or 24 (406 or 610 mm) O.C. 3 (76 mm) glass fiber batt RC-1 channel or equivalent one side Joints finished UL Des U305 1 4-3/4 (121 mm) 34 5/8 (15.9 mm) Type X gypsum panels 2 4 wood stud 16 (406 mm) O.C. Joints finished Optional veneer plaster 37 Based on studs at 24 (610 mm) O.C. 46 Based on studs at 24 (610 mm) O.C., 3 (76 mm) Thermafiber SAFB DESCRIPTION TWO-HOUR-RATED WOOD ASSEMBLIES 7.73 FIGURE FIRE TEST NO. RATING (HOURS) UL Des U301 2 6 (152 mm) 52 5/8 (15.9 mm) Type X gypsum panels 2 4 wood studs 16 (406 mm) O.C. Joints finished Optional veneer plaster UL Des U334 2 6-1/2 (165 mm) 59 5/8 (15.9 mm) Type C gypsum panels 2 4 wood studs 16 (406 mm) O.C. 2 Thermafiber SAFB RC-1 channel or equivalent one side Joints finished 62 Based on 6-1/4 (158 mm) fiberglass insulation, acoustical sealant bead at perimeter of partition FURRED WALLS Exterior walls are typically furred using wood or steel furring to which the gypsum panels are screw attached. Furring can be erected either vertically (preferred) or horizontally. Wood furring should be 2 2 nominal minimum size for nail application; strips may be 1 3 nominal size for screw attached. SYSTEM THICKNESS STC DESCRIPTION FURRING—WALL ELEVATION 7.74 Direct-attached furring channels can be fastened directly to the interior face of the exterior wall or applied using adjustable wall furring brackets and cold-rolled channels. Freestanding furring typically consists of 1-5/8 in. (41 mm) metal studs in top and bottom runners. For walls greater than 12 ft (3.7 m), use thicker (heavier gauge) studs or brace the stud at intermediate points to an available substrate or use a deeper stud dimension. Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 87, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Contributor: Del Shuford, AIA, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 108 I N T E R IO R CO NST RU CTION TYPICAL PERIMETER PARTITIONS Page 108 INTERIOR CONSTRUCTION CO MPO N E N T S GYPSUM BOARD TERMINATION AT CEILING 7.76 PERIMETER CONDITION WITH FULL-HEIGHT METAL STUD Metal studs are installed full height to the underside of the structure above, providing a more stable partition. Gypsum board extends up above the ceiling, creating a more finished appearance. Metal stud width allows for installation of selected standard devices, such as shallow junction boxes. A vapor retarder on the interior of the room (warm side of the partition) may be beneficial. BENDING Wet gypsum board is easily damaged and should be handled with care. When the gypsum board dries thoroughly, its original hardness is regained. BENDING RADII FOR DRY GYPSUM BOARD 7.78 GYPSUM BOARD THICKNESS FULL-HEIGHT PARTITION—3-1/8 IN. (79 MM) THICK 7.75 BENT LENGTHWISE BENT WIDTHWISEb 1/4 (6.4 mm) 5-0 (1.5 m)a 15-0 (4.6 m)a 5/16 (7.9 mm) 6-3 (1.9 m) 20-0 (6 m) 3/8 (9.5 mm) 7-6 (2.3 m) 25-0 (7.6 m) 1/2 (12.7 mm) 10-0 (3 m)a b 5/8 (15.9 mm) 15-0 (4.6 m) b ARCHWAYS Gypsum board may be applied to the inner face of almost any archway. For short radii, the gypsum board should either be moistened or have the back paper scored across the width with parallel score marks spaced approximately 1 in. (25 mm) on center with the core broken at each cut. GYPSUM BOARD FLOOR AND CEILING FIREPROOFING ASSEMBLIES Designs included here are suitable for all types of residential and commercial buildings, including those with single- and double-layer gypsum board facings and with sound attenuation blankets and resilient attachments. • Steel framed: Performance values up to four-hour fire resistance and STC 60 can be obtained. • Wood framed: Performance values up to two-hour fire resistance and STC 67 can be obtained. CURVED WALL FRAMING Gypsum board may be used to form almost any cylindrically curved surface. To prevent flat spots on the curved surface, framing members should be spaced closer together than required for typical flat wall or ceiling surfaces. For minimum radius ends, framing spacing should be not greater than 6 in. (152 mm) on center. Gypsum board should be mechanically attached to framing using nails or screws. PERIMETER CONDITION WITH METAL FURRING CHANNEL CURVED GYPSUM BOARD ASSEMBLY 7.77 The shallow depth of this type of partition does not allow for installation of some devices, such as junction boxes and receptacles. Where gypsum board extends above the ceiling, it creates a more finished appearance. A vapor retarder on the interior of the room (warm side of the partition) may be beneficial. Source: The Gypsum Construction Handbook, USG Corporation; Chicago, Illinois. NOTES 7.78 a. Two 1/4-in. (6.4-mm) pieces bent successively may be used to obtain a final thickness of 1/2 in. (12.7 mm) at the shorter bending radius. b. Shall not be permitted to be bent widthwise while dry. c. Bending radii for dry gypsum board should be not less than those given in table. d. Gypsum board may be permitted to be bent to radii shorter than those given in table if the face and back papers and core are thoroughly moistened. Contributor: Del Shuford, AIA, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 109 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 109 FLOOR ASSEMBLIES: 1- AND 1.5-HOUR-RATED C-JOIST 7.79 FIGURE FIRE TEST NO. UL Des L524 RATING (HOURS) 1 SYSTEM THICKNESS STC 8-5/8 (219 mm) NA 1/2 (13 mm) T&G plywood floor 7 (178 mm) 18-gauge steel joists 24 (610 mm) O.C. Two layers 1/2 (12.7 mm) Type C gypsum panels 11 (279 mm) 39 Based on 9-1/2 (242 mm) 16-gauge steel joists 11 (279 mm) 43 Based on 9-1/2 (242 mm) 16-gauge steel joists and 3 (76 mm) mineral wool batt 11-1/4 (285 mm) 56 Based on 9-1/2 (242 mm) 16-gauge steel joists and carpet pad 11-1/4 (285 mm) 60 Based on 9-1/2 (242 mm) 16-gauge steel joists and carpet pad with 3 (76 mm) mineral wool batt DESCRIPTION UL Des L524 1 9-1/4 (235 mm) NA 3/4 (19 mm) floor underlayment 1/2 (13 mm) T&G plywood floor 7 (178 mm) 18-gauge steel joists 24 (610 mm) O.C. Two layers 1/2 (12.7 mm) Type C gypsum panels GA-FC-1145 1 10-1/2 (260 mm) NA 2 (51 mm) concrete on steel deck 6 (152 mm) 18-gauge structural steel joists 24 (610 mm) O.C. RC-1 channel or equivalent 1/2 (12.7 mm) Type C gypsum panels Joints finished UL Des G564 1 13-7/8 (353 mm) 63 Carpet and pad 1 (25 mm) floor underlayment SRM-25 sound mat Corrugated steel deck min. 22 gauge Min. 8 (203 mm) 16-gauge steel C-joists 24 (610 mm) O.C. 3-1/2 (89 mm) mineral wool or glass fiber batt Drywall suspension system 5/8 (15.9 mm) Type C gypsum panels UL Des G551 1 14 (356 mm) 63 Engineered wood laminate Min. 1 (25 mm) floor underlayment SRM-25 sound mat Corrugated steel deck min. 22 gauge 9-1/4 (235 mm) 16-gauge steel joists 24 (610 mm) O.C. 3-1/2 (89 mm) mineral wool batt Drywall suspension system 5/8 (15.9 mm) Type C gypsum panels 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 110 I N T E R IO R CO NST RU CTION Page 110 INTERIOR CONSTRUCTION CO MPO N E N T S FLOOR ASSEMBLIES 7.80 FIGURE FIRE TEST NO. RATING (HOURS) SYSTEM THICKNESS STC DESCRIPTION UL Des L549 1 8-5/8 (219 mm) NA One-hour-rated steel truss Plywood flooring or floor underlayment over plywood subflooring Steel trusses Insulation optional in concealed space directly over gypsum ceiling membrane RC-1 channels or equivalent 5/8 (15.9 mm) Type C gypsum panels Joints finished UL Des L542 1 13-3/4 (349 mm) NA One-hour-rated truss 23/32 (18 mm) plywood 12 (305 mm) parallel chord wood floor truss, 24 (610 mm) O.C. Two layers 1/2 (12.7 mm) Type C gypsum panels Joints finished Optional veneer plaster UL Des L516 1 11-7/8 (302 mm) 59 One-hour-rated dimensioned lumber floor assembly 3/4 (19 mm) cementitious floor underlayment Plywood subfloor 2 10 wood joists 16 (406 mm) O.C. 3 (76 mm) mineral wool batt RC-1 channel or equivalent 1/2 (12.7 mm) Type C gypsum panels Joints finished Optional veneer plaster UL Des L511 2 12-1/4 (311 mm) NA Two-hour-rated dimensioned lumber floor assembly 1 (25 mm) nominal wood subfloor and finished floor 2 10 wood joist 16 (406 mm) O.C. RC-1 channel or equivalent Two layers 5/8 (15.9 mm) Type C gypsum panels Joints finished UL Des L570 1 12-7/8 (327 mm) 64 One- and two-hour-rated engineered joist floor assembly 1 (25 mm) cementitious floor underlayment Optional SRM-25 sound mat 19/32 (15 mm) wood perpendicular 9-1/2 (242 mm) “I” wood joist spaced max. 24 (610 mm) O.C. 3-1/2 (89 mm) mineral wool insulation RC-1 channel or equivalent Two layers 1/2 (12.7 mm) Type C gypsum panels Joints finished 12-3/4 (324 mm) 65 Based on 3/4 (19 mm) cementitious floor underlayment and vinyl tile 12-7/8 (327 mm) 66 Based on 3/4 (19 mm) cementitious floor underlayment and ceramic tile 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 111 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 111 HORIZONTAL MEMBRANE FIREPROOFING Horizontal membrane fireproofing is typically used for fire-rated corridor ceilings, stair soffits, and metal duct enclosures. ONE- AND TWO-HOUR-RATED CEILING ASSEMBLIES 7.81 FIGURE FIRE TEST NO. RATING (HOURS) SYSTEM THICKNESS STC DESCRIPTION NER-258 1 3-1/8 (79 mm) NA Horizontal membrane corridor ceiling and stair soffit 1 (25.4 mm) gypsum liner panels 2-1/2 (64 mm) steel C-H stud spanning horizontally 24 (610 mm) O.C. 5/8 (15.9 mm) Type C gypsum panels NER-258 2 3-1/2 (89 mm) NA Horizontal membrane corridor ceiling and stair soffit 1 (25.4 mm) gypsum liner panels 2-1/2 (64 mm) steel C-H stud spanning horizontally 24 (610 mm) O.C. 1/2 (12.7 mm) Type C gypsum panels GYPSUM BOARD STRUCTURAL FIREPROOFING STEEL BEAM INDIVIDUAL ENCASEMENT PROTECTION 7.83 PARTIAL-HEIGHT PARTITION 7.84 Source: Copyrighted work of USG Corporation, USG Gypsum Association Fire Resistive Design Manual, 18th ed., p. 15. CANTED WALL 7.85 Steel column fire protection with gypsum board enclosures offers fire ratings of two to four hours, depending on construction. All column systems are tested with the column size specified in the system. Fire-resistance ratings for the heavier steel columns are not applicable to the lighter steel columns. Beams, girders, and trusses should be protected by either a continuous ceiling membrane of either gypsum lath and plaster or gypsum board or by enclosing them individually. MEMBRANE-PROTECTED STEEL BEAMS— CONTINUOUS 7.82 Source: Copyrighted work of USG Corporation, USG Gypsum Association Fire Resistive Design Manual, 18th ed., p. 15. Contributor: Del Shuford, AIA, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 112 I N T E R IO R CO NST RU CTION SLOPED SILL 7.86 Page 112 INTERIOR CONSTRUCTION CO MPO N E N T S REVEAL DOOR JAMB DETAILS 7.89 GYPSUM BOARD PARTITION REVEAL 7.87 TOOLS AND EQUIPMENT The following is a sampling of the tools available to meet the needs of drywall contractors. Consult manufacturer’s literature for proper use. REVEAL WALL BASE DETAILS 7.88 NOTES 7.86 A sloped sill discourages sitting or the placement of trash. 7.87 Reveals may be inserted into walls using standard components of varying sizes and configurations. • Laser alignment tool: An extremely precise device that utilizes a visible laser beam for all construction alignment jobs. Provides maximum accuracy and speed for laying out partitions and leveling suspended ceiling grids. • Power fastener driver: Used to drive fasteners into concrete or steel for attachment of framing members. Available in air-driven and powder-driven models. • Channel stud shear: Cuts steel studs and runners quickly, cleanly, without deforming. Has fixed guides for sizes of 1-5/8, 2-1/2, and 3-5/8 in. (41, 64, and 92 mm). For use with a maximum steel thickness of 20 gauge. • Chop saw: The chop saw’s abrasive metal cutting blade cuts all steel framing members. Its steel base can be placed on a bench, saw horse, or floor for fast and efficient gang cutting of members. • Stud crimper: For setting and splicing metal studs, roughing-in door holders and window headers, setting electrical boxes and punching hanger wire holes in ceiling grids. • Drywall saw: Short blade and coarse teeth for cutting gypsum boards quickly and easily. • Keyhole-type utility saw: Saw for cutting small openings and making odd-shaped cuts. Sharp point and stiff blade can be punched through board for starting cut. • Circle cutter: Calibrated steel shaft allows accurate cuts up to 16 in. (406 mm) in diameter. • Kick lifter: Device is designed to move the panel forward as it lifts. Can be used for panels applied either perpendicular or parallel. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 113 INT E R IO R CONSTRUCTION COMPONENTS • Panel lift: Cradle-type lifter allows one-person application of drywall to side walls and sloped ceilings as well as level ceilings. Tripod base with rollers for easy movement. • Banjo: A box-type applicator that passes paper tape through a compartment filled with joint compound so that both materials are simultaneously applied to joints. • Taping and finishing knives: 4-, 5-, and 6-in. (102-, 127-, and 152mm) knives are designed for taping, fastener spotting, angle taping, and finishing; an 8-in. (203-mm) or wider knife for finish coating. The two narrower knives are available with either plane handle or with hammerhead handle. Other drywall finishing knives are available with blade widths from 1 in. (25 mm) up to 24 in. (610 mm) Long-handle models also available. • Hand sander: Sandpaper is attached with end clamps to the 3-1/4- by 9-1/4-in. (83- by 235-mm) baseplate. Models include those with wood or aluminum handles. • Pole sander: Long handle enables working areas with longer strokes. • Angle trowel: For interior corner finishing of veneer plaster and drywall jobs. Similar tool with narrower blades available for conventional plaster. May also be used to evenly apply joint compound. • Automatic taper: Tube-style device applies a metered amount of compound onto the tape, places the tape on the wall, and cuts the tape to length. Works for flat joints or corners. INTE R I O R CO N ST RU CT I O N 113 • Gypsum board dolly: For efficient transport of gypsum boards around the floors of a building. The load, centered over large side wheels, is easily steered and moved by one worker. • Folding trestle horse: Top surface provides work surface or stand-on work platform. Legs adjust in increments. • Scaffold: Portable and easy to set up. Wheels lock for safety and security. Wide variety of sizes and types of scaffold are available to meet job requirements. • Stilts: Convenient way to reach high areas on drywall, veneer plaster, and plaster jobs. Gives applicator full mobility plus height needed for ceiling work. Stilts have articulated joints to flex with ankle movement. Available in fixed-height and adjustable-height types. TOOLS AND EQUIPMENT USED WITH GYPSUM BOARD 7.90 Source: Copyrighted work of USG Corporation, USG Gypsum Construction Handbook, 6th ed., p. 439, R.S. Means Company, Inc., Kingston, Massachusetts, 2009. Contributors: Del Shuford, AIA, Gensler, Dallas, Texas. Sarah Bader, Gensler, Chicago, Illinois. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 114 I N T E R IO R CO NST RU CTION CONCRETE MASONRY UNITS Concrete masonry units (CMUs) are modular building units composed of aggregate particles embedded in a cementitious matrix. Load-bearing units and concrete brick are commonly used in building core and shell construction. Non-load-bearing units may be specified for partitions and are commonly used for fire protection of steel columns and fire-rated partitions. Concrete masonry units are available in a variety of colors, sizes, textures, configurations, and weights, to accommodate design, detailing, and construction. The textures may be smooth, ground, split, ribbed, or otherwise prepared to maximize design versatility. Smooth finishes and more color options are available with prefaced, integral glazed concrete masonry units. ACOUSTICAL CONSIDERATIONS FOR CONCRETE MASONRY UNITS The high mass of single-wythe concrete masonry unit walls results in relatively high sound transmission class (STC) ratings. These ratings are improved with the addition of furring, insulation, and gypsum wallboard surfacing. Sound waves lose power as they vibrate through the mass of the block, the air in the cavity, and the mass of the wallboard before reaching the listening area. The more air that is in the cavity wall, the higher is the STC rating. These walls have been shown to have good resistance at most frequencies, including low frequencies. CMU cavity walls for interior use can achieve STC ratings up to 79. Special products are available for spaces with high acoustical separation requirements. Both sound blocks and diffuser blocks have STC ratings above 52. Sound blocks are used for interior walls surrounding lecture halls, swimming pools, and theaters. A sound block is a CMU with one vertical slot per core, creating a Helmholtz resonator effect to deaden sound. Diffuser blocks are made of three interlocking units that combine to make up a wall. They create a Helmholtz resonator for sound absorption, and also provide good sound diffusion back into the source room. Diffuser blocks are designed with space for horizontal joint reinforcement. Their cores can be filed with grout or with insulating material. SIZES AND WEIGHTS Concrete masonry units are specified as width by height by length. They are manufactured in both English and metric modular sizes. NOTE 7.91 Metric conversions for CMUs and gypsum wallboard are given in nominal industry standard dimensions. Page 114 INTERIOR CONSTRUCTION CO MPO N E N T S CONCRETE MASONRY UNITS 7.92 CONCRETE MASONRY WALL ACOUSTICAL CONSTRUCTION 7.91 WALL TYPE DESCRIPTION STC RATING Interior cavity wall 4 (100 mm) split-face block 1 (25 mm) air space 2 (51 mm) rigid insulation 8 (200 mm) CMU 1-1/2 (38 mm) wood furring 1-1/2 (38 mm) fiberglass insulation 65 Interior cavity wall 4 (100 mm) split-face block 3-1/2 (89 mm) air space 2-1/2 (64 mm) fiberglass insulation 8 (200 mm) CMU 79 Interior cavity wall 4 (100 mm) split-face block 3-1/2 (89 mm) air space 2-1/2 (64 mm) fiberglass insulation 4 (100 mm) CMU 66 8 CMU wall 8 (200 mm) CMU 50 8 CMU wall system 8 (200 mm) CMU 2 (51 mm) Z-bars 1/2 (12.7 mm) gypsum wallboard 51 8 CMU wall system 8 (200 mm) CMU 2 (51 mm) Z-bars—2 sets 1/2 (12.7 mm) gypsum wallboard 52 8 CMU wall system 8 (200 mm) CMU 1-1/2 (38 mm) wood furring 1-1/2 (38 mm) fiberglass insulation 1/2 (12.7 mm) gypsum wallboard 54 8 CMU wall system 8 (200 mm) CMU 3 (76 mm) steel studs 1-1/2 (38 mm) fiberglass insulation 1/2 (12.7 mm) gypsum wallboard, one side 59 8 CMU wall system 8 (200 mm) CMU 3 (76 mm) steel studs 1-1/2 (38 mm) fiberglass insulation 1/2 (12.7 mm) gypsum wallboard, both sides 64 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 115 INT E R IO R CONSTRUCTION COMPONENTS TYPICAL CONCRETE MASONRY UNIT SHAPES 7.93 SINGLE-WYTHE MASONRY Single-wythe masonry wall construction is common for many applications, both load-bearing and non-load-bearing and interior and exterior walls. These single-wythe masonry systems are frequently used as interior partitions for fire protection. Single-wythe walls may be insulated on the interior or exterior. The insulation may be adhered or mechanically fastened directly to the masonry, or it may be installed in conjunction with conventional furring or studding systems. SINGLE-WYTHE CONCRETE MASONRY UNIT WALL 7.94 INTE R I O R CO N ST RU CT I O N 115 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 116 I N T E R IO R CO NST RU CTION STANDARD CMU WALL SECTIONS 7.95 Page 116 INTERIOR CONSTRUCTION CO MPO N E N T S ARCHITECTURAL CONCRETE Architectural concrete is a handcrafted, cast-in-place finish material. It differs in composition and quality level from conventional structural concrete. Architectural concrete requires coordination and quality control in the design and fabrication process. It is available in a wide variety of textures, colors, and finishes. Interior applications include walls, stairs, and other areas of monolithic exposed concrete. Considerations for architectural concrete installations include: • • • • Alignment and layout of architectural concrete formwork Consistency of surface texture Consistency of color Monolithic appearance without cracks Consult the American Concrete Institute for architectural concrete design recommendations and information. ARCHITECTURAL CONCRETE DESIGN Successful architectural concrete installations rely on the coordination of the designer, engineer, and contractor. Architectural concrete must be fabricated with as much precision as possible, as it is almost impossible to correct once installed. The three methods of modifying the appearance of a concrete surface finish are: • Material variation, which involves changing the size, shape, texture, and color of the coarse and fine aggregate, particularly in exposed aggregate concrete, and choosing white or gray cement • Form variation, which involves changing the texture or pattern of the concrete surface by means of form design, form liners, or joint edge treatments • Surface treatment, which involves treating or tooling the surface after the concrete has cured JOINT TYPES • Construction joints occur where concrete work is interrupted during construction, but they do not affect the structural integrity of the system. • Form joints occur where formwork joins or meets. • Control joints are placed to ensure that the concrete, which shrinks as it cures, will crack in predetermined locations. Factors influencing the location of cracks include the size and shape of the concrete member, steel reinforcement, and protection as the concrete cures. Members longer than 10 or 15 ft (3 or 4.5 m) will crack randomly unless control joints are provided. AGGREGATE Aggregate greatly affects the final appearance of the concrete surface. Aggregate should be selected on the basis of color, hardness, size, shape, gradation, method of exposure, durability, availability, and cost. Aggregate hardness and density must be compatible with structural requirements and weathering conditions. Sources for coarse and fine aggregates should be kept the same for an entire job to avoid variations in the final surface appearance, particularly in light-toned concrete. Following are the common types of aggregate and colors available: • Quartz is available in clear, white, yellow, green, gray, and light pink or rose. Clear quartz is used as a sparkling surface to complement other colors and pigmented cements. • Granite is known for its durability; it is available in shades of pink, red, gray, dark blue, black, and white. Traprock, such as basalt, can be used for gray, black, or green. • Marble offers the widest selection of colors: green, yellow, red, pink, gray, white, and black. • Limestone is available in white and gray. • Miscellaneous gravel, after being washed and screened, can be used for brown and reddish-brown finishes. Yellow ochers, umbers, buff shades, and pure white are abundant in riverbed gravels. • Ceramic exhibits the most brilliant and varied colors when vitreous materials are used. • Expanded lightweight shale may be used to produce reddish- Contributors: Grace S. Lee, Rippeteau Architects PC, Washington, DC. Stephen S. Szoke, PE, National Concrete Masonry Association, Herndon, Virginia. Brian E. Trimble, Brick Institute of America, Reston, Virginia. MASTERSPEC®, published by ARCOM, Salt Lake City, Utah. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 117 INT E R IO R CONSTRUCTION COMPONENTS brown, gray, or black aggregate. Porous and crushable, this shale produces a dull surface with soft colors. EXPOSED AGGREGATE An exposed aggregate surface is a decorative finish for concrete work achieved by removing the surface cement to expose the aggregate. Aggregates suitable for exposure may vary from 1/4 in. (6 mm) to a cobblestone more than 6 in. (152 mm) in diameter. The extent to which the pieces of aggregate are revealed is largely determined by their size. Size is generally selected on the basis of the distance from which it will be viewed and the appearance desired. SURFACE TEXTURE AND FORM LINER Patterned forms and liners make it possible to simulate in concrete the textures of wood, brick, and stone. The texture and resulting shadow patterns conceal minor color variations or damage that would be conspicuous and unacceptable on a smooth surface. Use of rustication strips at joints in textured liners simplifies form assembly. INTEGRALLY COLORED CONCRETE Colored concrete can provide a cost-effective simulation of natural stone or other building materials. Two standard types of cement are available, offering different shades of color: standard gray portland cement and white cement. Integrally colored concrete is made by adding mineral oxide pigments to concrete mixes made with one of these two types of cement. STONE WALLS New technologies in stone quarrying and fabrication, including the creation of thinner dimension stone and stone tile products, have made this material widely used in interior applications. Dimension stone is defined as quarried stone with usually one or more mechanically dressed surfaces. These are thick slabs of stone that are marked as they are cut for matched-pattern installations, such as book-matched or end-matched configurations. Dimension stone tiles are less than 3/4 in. (19 mm) thick. They provide the natural beauty of a stone surface without the weight, depth, and expense of dimension stone. However, their thinness makes stone floor tiles more prone to cracking from impact or normal floor deflection. Stone tiles are installed by either the thickset or the thinset installation method. TYPES OF STONE Stone is classified as igneous (formed by volcanic action), sedimentary (formed from deposits that have undergone consolidation and crystallization), or metamorphic (created when other kinds of rocks are changed by great heat and pressure inside the earth). • Granite is a hard, durable, low-maintenance stone. It is a grainy igneous rock that imparts a visual strength. Granite is relatively uniform in color and texture. Contributors: Reginald D. Hough, FAIA, New York, New York. D. Neil Rankins, RGAA/Virginia, Richmond, Virginia. • Marble is a metamorphic stone, identified by its variegated, veined surface, and is valued for its range of colors and luxurious surface. Marbles are comparatively soft, easily scratched stones that require dedicated maintenance, especially if a polished finish is selected. Marbles can be polished, honed, sawn, sandblasted, bush hammered, split faced, tumbled, and acid washed. • Limestone is a sedimentary stone, which varies in hardness, density, and porosity from one type to another. Oolitic limestone (eggstone) is made of spherical grains composed of concentric layers. Limestone’s color range is limited to a neutral palette of buff and gray. More commonly used as exterior cladding for buildings, limestone is susceptible to staining. Limestone finishes include polished, honed, sandblasted, flamed, bush hammered, tumbled, and acid washed. Some varieties of limestone can receive a high-honed (satin matte) finish with a higher degree of reflectivity than the standard honed finish. • Slate is a metamorphic stone, formed from shale and clay. Slate splits easily into thin sheets. The finish resulting from the natural face is referred to as a cleft finish. Slate can also be sand rubbed to a smooth finish or honed. • Travertine, a sedimentary stone, is distinguished by its natural cavities, formed by plants embedded during the rock’s formation, which must be filled to achieve a smooth surface. Filling materials are typically portland cement, epoxy resins, or polyester resins. Though travertine is a type of limestone, some types that take a polish are classified as marble. It is popular for use as a flooring material, because its visual texture conceals dirt much better than most other stones. • Onyx is a decorative stone prized for its unique characteristics, including colored and banded patterns. Onyx is formed from quartz crystals, and the appearance can be enhanced by chemical treatment. Onyx is typically translucent, is relatively soft, and is brittle in its natural state. Treatment with resins can improve its performance and durability. • Quartzite is a metamorphic stone, formed from recrystallized sandstone. Quartzite contains silica, which contributes to its density and durability. Quartzite is available in honed, sandblasted, and split- or cleft-faced finishes. Due to its composition, quartzite is easily split, and bullnose or ogee-type details may be difficult to fabricate. • Sandstone is a coarse-grained sedimentary stone. It is composed of quartz and is bonded with silica, calcium carbonate, or iron oxide. Different iron oxides provide variation in colors, ranging from yellow, buff, and brown to reds. Related stone types include bluestone, brownstone, and flagstone. Sandstone can be honed, sawn, and split faced. Interior uses for sandstone include wall panels, interior paving, furniture, and casework. STONE FINISHES The stone finish affects the perception of the color, the texture, and the slip resistance of stone used in interiors. • Polished finishes provide a mirror gloss with sharp reflections, which brings out the stone’s full depth of color and pattern. • Honed finishes have a satin or dull sheen with little or no gloss. These surfaces are often good choices for commercial floors because of their slip resistance; however, they are susceptible to stain absorption. INTE R I O R CO N ST RU CT I O N 117 • Sawn finishes are textures that are not processed after the slab has been sawn from the block of stone. The texture is typically nondirectional and consists of circular markings and grooved surfaces. • Sandblasted finishes are achieved by blasting the stone surface with sand to create a coarse, nondirectional texture. Depending on the size of the grains of sand used in this surface treatment, fine, medium, or coarse textures are created. Interior paving stone with a sandblasted finish is inherently slip resistant, although the texture will be worn down to a honed finish under heavy pedestrian traffic. • Acid-washed finishes are produced by the application of acidic solutions to the stone surface to create a rustic texture. This texture is applied to calcium-based stones, such as marbles and limestones; quartz-based stones such as granite are resistant to this finish. • Thermal, also known as flamed, finishes are achieved by the application of intense flaming heat to the surface of the stone. The finish texture is coarse and irregular, following the crystal structure of the stone. A thermal finish is generally lighter in color, and the stone characteristics are less pronounced than in polished or honed finishes. Thermal finishes are typically applied to granite. • Waterjet, or hydro, finishes are created by the use of high-pressure water forces, which texture the surface and highlight the color of the stone. Waterjet finish textures fall between honed and thermal finishes. • Cleft-face finishes are natural textures produced from cleaved, naturally foliated stones, including slate and quartzite. Textures vary according to the density of the stone; very dense stones will cleave in flatter planes than less dense stones, which will have a more irregular texture when split. • Tumbled finishes impart an antique appearance to the stone. Typically used on small stone blocks, the tumbling process softens edges and corners and rusticates the surface of the stone. • Bush-hammered and tooled finishes are created by striking the stone surface with tools to create surface texture. Stones receiving a bush-hammered or tooled finish must be of a sufficient density and thickness to withstand the impact of the tools. • Split-faced textures are similar to that of cleft-faced stone, but are used on stones that are not naturally foliated. Split-faced textures are created using either a guillotine or wedges, the latter of which are power driven into the stone. Surfaces created range from fairly flat, consistent textures to textures similar to rougher thermal finishes. STONE MASONRY PATTERNS AND VENEERS Structural bond refers to the physical tying together of load-bearing and veneer portions of a composite wall. Structural bond can be accomplished with metal ties or with stone units set as headers into the backup. Ashlar masonry is composed of squared-off building stone units of various sizes. Cut ashlar is dressed to specific design dimensions at the mill. Ashlar is often used in random lengths and heights. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 118 I N T E R IO R CO NST RU CTION Page 118 INTERIOR CONSTRUCTION CO MPO N E N T S RUBBLE STONE MASONRY PATTERNS—ELEVATIONS 7.96 CUT STONE MASONRY PATTERNS—ELEVATIONS 7.97 GLASS UNIT MASONRY Glass unit masonry, commonly referred to as glass block, is a diverse building material whose many applications exhibit its multifaceted characteristics. The varying forms of glass block—type, thickness, size, shape, and patterns—along with the methods of installation can be combined to create unique design solutions. Applications range from entire facades, windows, interior dividers, and partitions to skylights, floors, walkways, and stairways. In all applications, glass block units permit the control of light, both natural and artificial, for function or drama. Glass block also allows for control of thermal transmission, noise, dust, and drafts. With the use of thick-faced glass block or solid 3 in. (76 mm) bullet-resistant block, security can also be achieved. SECTIONS AT SUPPORTS 7.98 GLASS MASONRY UNIT TYPES The basic glass block unit is made of two halves fused together with a partial vacuum inside. Faces may be clear, figured, or with integral relief forms. Glass block is available in thicknesses ranging from a minimum of 3 in. (75 mm) nominal for solid units to a maximum of 4 in. (100 mm) nominal for hollow units. SQUARE GLASS BLOCK SIZES 7.99 U.S. SIZES 6 6 (5-3/4 5-3/4 actual) METRIC SIZES AVAILABLE THROUGH U.S. DISTRIBUTORS 115 115 mm 1⁄2 7-1⁄2 190 190 mm 8 8 (7-3⁄4 7-3⁄4 actual) 240 240 mm 12 12 (13-3⁄4 13-3⁄4 actual) 300 300 mm Solid glass block units (glass bricks) are impact resistant and allow through vision. Surface decoration may be achieved with fused-on ceramic, etching, or sandblasting. A stipple pattern embossed on the exterior face is also available. Contributors: George M. Whiteside III, AIA, and James D. Lloyd, Kennett Square, Pennsylvania. Building Stone Institute, New York, New York. Alexander Keyes, Rippeteau Architects, PC, Washington, DC. Christine Beall, NCARB, CCS, Austin, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 119 INT E R IO R CONSTRUCTION COMPONENTS GLASS MASONRY UNIT TYPES 7.100 SPECIAL CORNER SHAPES 7.103 INTE R I O R CO N ST RU CT I O N 119 PANEL DIMENSIONS MAXIMUM PANEL DIMENSIONS 7.104 End block units have a rounded, finished surface on one edge. These units may be used to terminate interior partitions or walls or, when installed horizontally, as space dividers. END BLOCK 7.101 GLASS UNIT MASONRY STC RATINGS 7.102 STC SIZE PATTERN ASSEMBLY CONSTRUCTION 31 8 8 ´ 3 (203 ´ 203 ´ 76 mm) All patterns 31 8 8 ´ 3 (203 ´ 203 ´ 76 mm) All patterns Silicone system 37 8 8 ´ 4 (203 ´ 203 ´ 102 mm) All patterns Mortar 40 8 8 ´ 4 (203 ´ 203 ´ 102 mm) with LX fibrous filter All patterns Mortar 48 8 8 ´ 4 (203 ´ 203 ´ 102 mm) thick-faced block Thick block Mortar 53 8 8 ´ 3 (203 ´ 203 ´ 76 mm) solid units Solid block Mortar Silicone system BLOCK TYPE AND FACE THICKNESS INTERIOR AREA SQ FT (SQ M) INTERIOR HEIGHT INTERIOR WIDTH Standard 0.025 (0.6 mm) 250 (23.2) 20-0 (6 m) 25-0 (7.6 m) Thinline series 85 (7.9) 10-0 (3 m) 15-0 (4.6 m) Solid glass brick 3 (76 mm) 100 (9.3) 10-0 (3 m) 10-0 (3 m) 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 120 I N T E R IO R CO NST RU CTION Page 120 INTERIOR CONSTRUCTION CO MPO N E N T S PANEL ANCHOR CONSTRUCTION 7.105 GLASS BLOCK PARTITIONS AND DETAILS TYPICAL PARTITION WITH HORIZONTAL REINFORCING 7.107 CURVED PANEL CONSTRUCTION Curved areas should be separated from flat areas by intermediate expansion joints and supports. Expansion joints should be installed at every change of direction of a multicurved wall, at points of curved wall intersection with straight walls, and at center of curvature in excess of 90°. PREFABRICATED PARTITIONS MOVABLE WALLS RADIUS MINIMUMS FOR CURVED PANEL CONSTRUCTION 7.106 BLOCK SIZE INSIDE RADIUS 4 ´ 8 (102 ´ 203 mm) 32 (813 mm) NUMBER OF BLOCKS IN 90° ARC 13 JOINT THICKNESS INSIDE OUTSIDE 1/8 (3 mm) 5/8 (16 mm) 6 ´ 6 (152 ´ 152 mm) 48-1/2 (1,232 mm) 13 1/8 (3 mm) 5/8 (16 mm) 8 ´ 8 (203 ´ 203 mm) 65 (1,651 mm) 13 1/8 (3 mm) 5/8 (16 mm) 12 ´ 12 (305 ´ 305 mm) 98-1/2 (2,502 mm) 13 1/8 (3 mm) 5/8 (16 mm) Movable walls, also referred to as relocatable or portable walls, or as demountable partitions, are factory-fabricated, site-assembled partition systems with a variety of wall surfaces. Connectors, bases, and other components are designed as part of the system and are installed with far fewer tools than required for constructed gypsum board partitions. Recent improvements in design have led to systems with better privacy, security, and ability to block sound. Solid panels designed to reduce noise are available with sound transmission class (STC) ratings ranging from 44 to 48. FLEXIBILITY Movable walls are increasingly used in offices to meet frequently changing requirements. They save construction time as compared to traditional, constructed gypsum board partitions, and may be less expensive to install. Taping and sanding (and the dust and debris these operations generate) inherent in standard gypsum board wall construction is eliminated. Systems may even be reconfigured while an office space remains in use. Movable walls are designed to be reconfigured without extensive renewal or repair of floor and ceiling finishes. Some systems are attached to the flooring and to the ceiling grid, which makes it possible to move the system with virtually no damage to these surfaces. SUSTAINABILITY Movable walls can help meet sustainability goals. Components can be readily reconfigured and reused. Some products contain up to 30% recycled materials and are 70% recyclable after use. Their flexibility leads to reuse rather than disposal, greatly reducing the amount of waste destined for landfills. Contributors: Brian Cooper, AIA, and Jana Gunsul, AIA, DES Architects & Engineers, Redwood City, California, with Nick Loomis, Senior Systems Engineer, Pittsburgh Corning Corporation, Pittsburgh, Pennsylvania. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 121 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 121 MOVABLE WALL TYPES CONNECTIONS WIRING Today, movable wall systems typically consist of steel or extruded aluminum frames, with glass or solid panels. Frames in some systems can span up to 10 ft (3 m) without intermediate supports. Several manufacturers claim that their movable walls provide better speech privacy than gypsum wallboard. Connection details from frame to frame and from frame to ceiling, floor, or wall vary widely among manufacturers. Some of the options available include: Movable walls are typically designed to readily accommodate power and data cabling. Access can be provided at the wall base and at ADA-mandated and desk heights. Systems are available with wall cavities that accept hard-wiring and quick-disconnect systems as well as standard UL/CSA-approved boxes. • Glass types include clear, translucent, opaque, patterned, double glazed, and acoustical glass. Systems are available with clerestory glazing. • Solid materials include metal, laminate, fabrics, and wood veneer. • Some systems use modular cladding tiles in a wide variety of finishes, including smart whiteboards and fabric-wrapped mediumdensity fiberboard (MDF) core tackboards, back-painted glass, and front and rear projection screens. • Painted steel frame with flush frame-to-frame connections • Dry butt-glazed glass-to-glass corners • Standard panels that can be cut on-site to accommodate windowsills, columns, and other obstructions • Carpet grippers and ceiling track clips that connect and release without damaging interior finishes • Acoustically sensitive polyvinyl chloride (PVC) zipper panel connector strips and angled or pivot corner connections • Aluminum connection posts with two-, three-, and four-way connections MOVABLE WALL POWER AND COMMUNICATIONS CABLE WIRING 7.109 MOVABLE PANEL CONFIGURATIONS 7.108 Source: Teknion Corporation. DOORS Movable walls are available with a wide array of door types, including: • Hinged glass doors 40 and 42 in. (1,016 and 1,067 mm) wide and 3/8 in. (10 mm) thick • Hinged solid doors 40 and 42 in. (1,016 and 1,067 mm) wide and 1-3/4 in. (44 mm) thick • Sliding glass doors • Pocket doors 48 in. (1,219 mm) wide and 1-3/4 in. (44 mm) thick that recess into 48-in. (1,219 mm) pockets inside wall panels • Barn doors hung on the wall face, 40, 42, or 48 in. (1,016, 1,067, or 1,219 mm) wide. Available in glass, solid, or solid with glass insert • Pivot doors Source: Courtesy Steelcase Inc. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 122 I N T E R IO R CO NST RU CTION WIRE MESH PARTITIONS Wire mesh partitions are useful where security is needed in combination with visibility and air circulation, for example, in storage facilities, computer labs, and payroll distribution areas. The wire mesh typically has 1-1/2-in. (38-mm) openings in a diamond orientation. Smaller openings and square mesh are available at a higher cost. Standard wire mesh partitions are freestanding panels bolted together and supported by floor anchors. Panels are available in widths from 9 in. (229 mm) to 60 in. (1,524 mm), with a maximum height of 12 ft (3.7 m). Multiple panels can be stacked for greater heights. A variety of hardware and accessories are available, including ceiling panels, trimmed cutouts, hinged and sliding doors, Dutch doors, drop-shelf and slide-up and side-hinged service windows. Components are factory-painted steel. Page 122 INTERIOR CONSTRUCTION CO MPO N E N T S PATH OF EGRESS The path of egress is established by the authorities having jurisdiction. Additional means of egress may be needed, as the space is effectively divided into two separate rooms when the operable partition is in place. In this case, 2010 ADA Standards for Accessible Design for the additional means of egress are typically enforced. 2010 ADA Standards for Accessible Design–compliant pass doors designed for accessibility are available. These pass doors have no thresholds; they open and operate with no more than 5 lbf (22 N), by hardware requiring no gripping or twisting to operate; and they have a clear opening 32 in. (813 mm) wide with a 90° swing. can be given silk-screened, embossed (raised), or debossed (depressed) patterns. Fabric can be used as an interlayer. Dichroic interlayers give the product an iridescent sheen. High-resolution photographic images can be embedded in the panels. Custom interlayers are also available. Panel finishes range from high gloss to opaque. A variety of textures can be applied to the surfaces, with the front and back receiving different treatments, if desired. STACKED PANEL STORAGE 7.111 OPERABLE PANEL PARTITIONS Operable partitions allow the size of rooms to be tailored to specific events, making possible maximum utilization of space. They are available as: • Single-panel partitions: These are the most versatile solution for the largest openings, remote storage pockets, and complex layouts. Suspended from an overhead track, they can accommodate wide variations in floor conditions. Single-panel partitions are available with one- and two-hour fire ratings for multipurpose rooms, exhibition halls, and commercial buildings. • Paired-panel partitions: These are the most efficient solution for straight-line openings that do not involve multiple locations or offset storage, such as classrooms, conference or meeting rooms, or office space. Pairs of hinged-together panels are stored at either or both ends of their run, and are relatively quick and easy to set up. • Continuously hinged panel systems: Panels connected with hinges are operated electrically (with a key-operated switch) or manually. Acoustical bottom seals set automatically when the panel run is fully extended to avoid damage from misuse. They are used in hotel ballrooms, gymnasiums, multipurpose rooms, civic and convention centers, classrooms, and meeting and conference rooms. PANEL STORAGE CONSIDERATIONS Panel storage garages must be designed with the panel manufacturers during the design development phase to ensure that adequate space, size, and configuration are provided. Configuration of the storage garage varies depending on the selected system, as well as the garage door opening width, swing, and closing hardware. Pocket doors with a variety of finish options are available to conceal storage areas. CONFERENCE ROOM WITH OPERABLE PARTITION 7.110 ARCHITECTURAL RESIN PANELS FABRICATION Architectural resin panels include partitions and wall inserts, shojistyle screens and dividers, railings and balustrades, interior windows, indoor signage, point-of-purchase displays, and furniture and furniture trims. The panels are available as translucent or clear sheets, with embedded materials and interlayers, and as prepatterned sheets. Some manufacturers also supply hardware and edge trims for mounting sheets horizontally or vertically. Most architectural resin panels can be laser cut, routed, welded, drilled, die punched, and hot or cold bent. They can be joined by screws, rivets, or bolts. Edges can be polished by commercial edge-finishing equipment, sanding, solvents, flame polishing, or buffing. Many architectural resin products contain 40 to 100% preconsumer recycled resin. Panels with a uniform composition (without other embedded materials) may be more easily recycled after use. Some embedded materials, such as glass from beverage bottles, may themselves have been recycled. Durable materials with long lives will stay out of the waste stream longer, but may be more difficult to recycle at the end of their useful life. Source: lauckgroup, Dallas, Texas. NOTE 7.110 a. Panels are hung from overhead track fastened to structure above for stability. Contributors: Margery Morgan, Symmes Maini & McKee Associates, Cambridge, Massachusetts. Stephen Luk, Brennan Beer Gorman Architects, New York, New York. Among the decorative treatments available are embedded natural materials such as shells, grasses, fibers, leaves, and twigs. Thin wood veneers can be laser cut and encased in resin. Clear resin can be used to embed stone and wood into thicker panels. Surfaces Hardware available from architectural resin panel manufacturers includes: • Stand-offs: Raise panels off horizontal or vertical surfaces. • Cable systems: Suspend panels from horizontal surfaces. • Rod systems: Secure panels and support their weight from ceilings and walls. • Door systems: Include sliding and hinged hardware for office spaces, closets, and cabinets. • Railing hardware: Used for stairways, balconies, balustrades, and ramps. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 123 INT E R IO R CONSTRUCTION COMPONENTS ARCHITECTURAL RESIN PANEL MATERIALS 7.112 RESIN USES INTE R I O R CO N ST RU CT I O N 123 RESIN PANELS AT TERRACE—SECTION 7.115 CHARACTERISTICS APPEARANCE SUSTAINABILITY Acrylic resin Paneling, partitions, lighting and ceiling accents, interior doors and windows Translucent, lightweight, impact resistant, thermoforms into complex shapes High-gloss, matte finish, renewable surface, many edge profiles available Available as recycled resin Chemical-resistant acrylic resin High-touch surfaces; partitions; horizontal countertops, tabletops; sliding doors Same as acrylic resin Same as acrylic resin Available as recycled resin PETG resin (proprietary licensed process) Spaces requiring Class A/B fire rating, large surface areas, curved railings and partitions Low flammability, 1/2 weight, 40 times impact resistance of glass, cold-forming bends Very clear; wide range of treatments, colors, interlayers Available with up to 98% recycled resin Polycarbonate resin High-traffic areas, spaces requiring greater safety standards, large surface areas 1/2 weight, 250 times impact resistance of glass, low flammability, good optical properties, thermoforms Similar to acrylic, but more durable, glasslike Not indicated as containing recycled materials by manufacturers High-density polyethylene Partitions, sliding doors Structurally strong, lightweight Translucent sheets with cellular core 100% postconsumer recycled Translucent resin solid surfacing Horizontal or vertical partitions, countertops Thick, stable, can support structural load 1/2, 1, and 2 (13, 25, and 51 mm) sheets can be bent into radius curves Not listed as containing recycled materials RESIN PANEL STAND-OFF DETAILS 7.113 RESIN PANELS AT TERRACE—ELEVATION 7.114 HONEYCOMB PANELS Source: Lumicor. MAINTENANCE Cleaning supplies for architectural resin panels must be carefully selected with guidance from the manufacturer. Special plastic polishing kits are available. Do not use cleaners containing chlorine, ammonia, or rubbing alcohol, which may cause discoloration. Solvents such as acetone, alcohol, gasoline, benzene, and many other similar chemicals should not be used. Abrasive cleaners should not be used. Squeegees, scrapers, synthetic rags, and paper towels containing calcium carbonate can scratch surfaces. Antistatic sprays can be used to counteract dust-attracting electrostatic charges. A heat gun can be used to remove scratches and scuff marks from PETG panels. Honeycomb panels consist of thin, foil-like cellular metallic cores bonded between lightweight facings. Panels are inherently stiff and require minimal structural support. Manufacturer-supplied parts minimize hardware and on-site labor. Interior honeycomb panels can be used for interlocking wall systems, curved panels, column covers, countertops, furniture, and doors. Several types are available for interior and exterior use. Interior products include: • Fiberglass sheet facings are laminated to aluminum or polymer honeycomb cores for panels 3/4 in. (76 mm) thick. Uses include walls, doors, and ceilings. Wet applications such as showers and saunas are possible. Can be used for vertical surfaces and inlays in furniture. • PETG, polycarbonate, or acrylic sheet facings are bonded to tubular polycarbonate cores for panels 3/4 in. (76 mm) thick. Uses are the same as above. • Translucent polymer resin facings are cast directly onto aluminum or polymer honeycomb cores. These panels are 1 or 11/2 in. (25 or 38 mm) thick. Translucent polymer resin panels are used for walls, sliding or pivot doors, ceilings, wet applications, and furniture. They are strong enough for tabletops, countertops, and workstation surfaces. Interlocking wall framing systems are available from the manufacturer. • Mica laminates bind mineral mica flakes with either fiberglass and shellac (amber sheets) or alkyd vinyl resin (silver sheets) to 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 124 I N T E R IO R CO NST RU CTION create translucent laminate sheets. The mica flakes make up over 90% of the panel material, and the panels can be recycled into industrial-grade panels after use. They are used for walls, doors, and ceilings, but require additional metal or wood framing. These panels can also be used for vertical surfaces, laminates, or inlays in furniture. Page 124 INTERIOR CONSTRUCTION CO MPO N E N T S GLASS GUARDRAIL 7.118 GLASS AND METAL GUARDRAIL 7.119 HONEYCOMB PANEL SQUARE CORNER POST 7.116 Source: © Panelite LLC 2009. HONEYCOMB PANEL U-CHANNEL 7.117 CABLE RAIL END POST WITH TENSIONERS 7.120 Source: © Panelite LLC 2009. INTERIOR SCREENS AND GUARDS Railing systems are available for interior or exterior use with wood or vinyl posts and cable, metal baluster, or glass infill panels. Careful measuring is required. ADA-compliant systems are also available. Safety concerns about people climbing horizontal railings have limited their use. Cable railing systems are not easy to climb, as the cables are very thin and flexible. Cable railings with tensioners are available that allow installers to cut and tighten cable on-site. Tensioner bases can accommodate angles up to 45° up, down, and from side to side. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 125 INT E R IO R CONSTRUCTION COMPONENTS COMMON TOP RAILS 7.121 WINDOWS AND GLAZING GLASS Glass is a hard, brittle amorphous substance made by melting silica (sometimes combined with oxides of boron or phosphorus) with certain basic oxides (notably sodium, potassium, calcium, magnesium, and lead) to produce annealed flat glass by a controlled cooling process. Most glasses soften at 932 to 2,012°F. Minute surface scratches in manufacturing greatly reduce glass strength. INTE R I O R CO N ST RU CT I O N 125 SECURITY GLASS 7.123 ers. If laminated glass is broken, the glass remains bonded to the interlayer, offering protection from injury; this makes it popular for use in skylights. LAMINATED GLASS 7.122 TINTED AND REFLECTIVE GLASS Tinted glass was developed to control solar heat gain and glare. Float glass is available tinted in green, bronze, gray, and blue, in thicknesses ranging from 1/8 to 1/2 in. (3 to 13 mm). The glass absorbs a portion of the sun’s energy due to its admixture content and thickness; it then dissipates the heat to both the exterior and the interior. The thicker the glass is, the greater the solar energy absorption. Newer tinted glass types allow more visible light transmission, while blocking a higher percentage of infrared energy than standard tinted glass. FLOAT GLASS LEADED STAINED GLASS Generally accepted as the successor to polished plate glass, float glass has become the quality standard of the glass industry. More than 95% of the glass manufactured in the United States is float glass. It is manufactured by floating molten glass on a surface of molten tin. Because the molten metal is denser than the glass, the two liquids do not mix together. This process produces a glass with very uniform thickness and flatness. After forming, the glass is cooled by a controlled process known as annealing. Decorative stained glass is characterized by pieces of glass joined together with lead cames (H-shaped strips) of various widths. Varying the widths adds to the window’s decorative effect. Joints are soldered on both sides of the panel. To prevent leakage, a mastic waterproofing material is inserted between the glass and the came flange. Annealing relieves internal strains that may have developed during the manufacturing process. It ensures that the glass does not cool and contract at different rates across its surface. If glass is not annealed, it may fracture from differential stresses throughout the sheet when it reaches room temperature. Float glass is available in thicknesses ranging from 1/8 to 7/8 in. (3 to 22 mm). STRENGTHENED GLASS There are several types of glass with increased strength: fully tempered, heat strengthened, laminated, and wire glass. FULLY TEMPERED GLASS Fully tempered glass is produced by heating float glass and then suddenly cooling it with special blowers. Fully tempered glass is three to five times more resistant to impact, applied pressure, and bending stresses than annealed glass, because the surface tension must be overcome before the glass can be broken. HEAT-STRENGTHENED GLASS The heat-strengthened glass manufacturing process is similar to that of fully tempered glass, except that the glass is only partially tempered. Heat-strengthened glass is about twice as resistant to breakage as float glass. LAMINATED GLASS Laminated glass consists of two or more layers of glass and an interlayer material sandwiched together to form a single sheet. Annealed, fully tempered, heat-strengthened, and wire glass types can be laminated. Security glass (bullet or burglar resistant) and acoustical glass are types of laminated glass using thicker interlay- Contributors: Jana Gunsul, AIA, DES Architects & Engineers, Redwood City, California. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. Another method of joining the pieces of glass is to band the edges of the glass with a copper foil tape, burnished to the glass and then soldered with a continuous bead of solder on both sides. REFLECTIVE GLASS WIRE GLASS Wire glass has wire mesh or parallel wires rolled into the center of the glass sheet. It is available in various patterns and pattern sizes such as square-welded mesh, diamond-welded mesh, and linear parallel wire. Pattern sizes range from 1/2 to 1 in. (13 to 25 mm), depending on pattern type. Some distortion, wire discoloration, and misalignment are inherent. If breakage occurs, the wire helps to hold the glass fragments in the opening. However, sharp glass edges can cause contact injuries. This is the standard glass type used for fire-rated doors or partition assemblies. SAFETY GLASS Safety glass is glazing material that breaks in a way that reduces the likelihood of cutting and piercing injuries if shattered. Fully tempered glass and laminated glass qualify as safety glass. Fully tempered glass breaks into small cubical pieces. If laminated glass is shattered, the broken glass adheres to the interlayer. SECURITY GLASS Security glass is composed of multiple layers of glass and/or polycarbonate plastic laminated together under heat and pressure with a polyvinyl butyral (for glass) or polyurethane plastic (for polycarbonate) film. It is available in multilayer laminated glass, insulating, laminated insulating, and double-laminated insulating or spaced configurations. Thicknesses range from 3/8 to 2-1/2 in. (10 to 64 mm) as a laminated product and up to about 4-3/4 in. (121 mm) for insulating and spaced construction products. Reflective glass reduces the amount of incident light transmitted, absorbed, and reflected by portions of the light and energy spectrum, thus improving the energy balance within a building. Typically, Type I (hard coat or pyrolitic) coatings, which are more scratch resistant than Type II (sputtered or soft-coat) coatings, are used on exposed glass surfaces. Reflective coatings are derived from metals, and are applied to glass based on the glazing system requirements. Pyrolitic reflective coatings on the outside surface are susceptible to exterior environmental factors. Reflective coatings on inner surfaces are protected from damage. Reflective glass can be used in interior applications such as shower doors and enclosures, countertops, wall cladding, and furniture. ENERGY-EFFICIENT GLASS LOW-EMISSIVITY GLASS Low-emissivity (low-E) glass was developed to address energy efficiency concerns for glazing. Hard or soft metallic coatings are applied to the glass, based on application type. Low-E coatings provide more reflectivity for the shortwave solar energy that strikes the glass at a high angle of incidence during the summer, while permitting this warmth to enter during the winter when the angle of incidence is lower. Low-E coatings are applied to the inside (side 2) on the first pane of glass in a double-glazed unit. The overall light transmission rate is higher than in tinted and reflective glass types. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 126 I N T E R IO R CO NST RU CTION INSULATING GLASS Insulating glass acts as a barrier to conductive heat loss. Insulated glass units are created by sealing an air pocket between two lights of glass, separated by a spacer. The energy efficiency of insulated glass can be increased by adding more layers of glass, or by the use of thin heat-reflecting films suspended between the spacers. Page 126 INTERIOR CONSTRUCTION CO MPO N E N T S POLYMER-DISPERSED LIQUID CRYSTAL DISPLAY 7.125 Insulated glass dampens vibrations and sound. Insulated glass units may be created to protect and seal specially treated glass, such as sandblasted glass surfaces. ACID ETCHING In the process of acid etching, sandblasted glass is submerged in a bath of hydrofluoric and hydrochloric acids to create a hardened, sealed surface. The glass appears matte, with a soft, light-diffusing quality. Depending on the coarseness of the sandblasting grit, the etched texture may be relatively smooth or grainy. Acid-etched glass may be coated or silvered. It does not show dust, dirt, or fingerprints, and is used in retail, residential, and commercial applications for tabletops, counters, shelving, wall cladding, stair treads, and other interior architectural elements. Stencils and etching creams are available to etch smaller areas of glass for signage, mirrors, and windows. SOUND CONTROL GLASS Laminated, insulating, laminated insulating, and double laminatedinsulating glass products are commonly used for sound control. STC ratings from 31 to 51 are available, depending on glass thicknesses, air space size, polyvinyl butyral film thickness, and number of laminated units used in insulating products. SPECIALTY GLASS TYPES TEXTURED GLASS Textured patterned glass is also known as rolled or figured glass. It is made by passing molten glass through rollers that are etched to produce the design. Designs include flutes, ribs, grids, and other regular and random patterns, which provide translucency and a degree of obscurity. Usually only one side of the glass is imprinted with a pattern. Patterned glass can be silvered, sandblasted, or have applied colored coatings. One form of textured glass is impression glass, in which a clear resin, applied to the glass, is impressed with a pattern. APPLIED FILMS Applied films can be used to modify the appearance or performance of glass. Mylar films can be permanently bonded to the glass with nonyellowing adhesives to create special designs. Tinted films are used as a low-cost alternative to tinted glass in retrofits of existing glass in commercial, residential, and automotive applications. Clear, tough films are available with a Category II safety glazing alternative for glass that is too thin, textured, or shaped so that it cannot be tempered. Applied films are used in jewelry store windows and display cases, where additional protection is needed without affecting the visual quality of the glass. Nylon-fiber-reinforced adhesive-backed films are used on the backs of mirrors for wardrobe doors and wall cladding where safety is a concern but where tempering would cause unacceptable visual distortion. PHOTOVOLTAIC GLASS There are two types of photovoltaic (PV) glass: crystalline silicon sandwiched between two layers of glass, and thin-film amorphous silicon applied to an interior-facing glass surface. When these arrangements are exposed to sunlight, they generate either direct current (DC) or alternating current (AC) power, which is transferred by concealed wiring to the building’s power system. Pressure bar framing systems or structural silicone, flush-glazed curtain walls and skylights, awnings, sunshades, light shelves, and roof panels are some of the systems that can incorporate PV glass. Both types of PV glass are used for opaque curtain wall spandrel panels and can be used for curtain wall or skylight vision glass if the quality of daylighting and visibility is acceptable. PRIVACY GLASS BLIND GLASS Blind glass is float glass that is acid etched on both sides in a linear, offset pattern, obscuring visibility when viewed perpendicular to the glass. Visibility through the glass is possible when viewing at a 45° angle. Produced in 3/16- and 5/16-in. (5- and 8-mm) thicknesses, the thicker glass is more effective for a see-through effect, while the thinner glass is suited to areas requiring more privacy, such as in doors and in furniture applications. MIRRORS Mirrors are created by coating a piece of glass with a reflective coating of silver, backed with copper, and protected by an epoxy paint top coat. Tinted and clear glass may be silvered with the pyrolitic process to produce mirrors. ELECTROCHROMIC GLASS Electrochromic glass switchable privacy glazing, identified as polymer-dispersed liquid crystal (PDLC), consists of liquid crystals that are enclosed in transparent polymer capsules. The capsules are sandwiched between two sheets of transparent electroconductive film. When voltage is applied, the liquid crystals line up in rows, allowing light to pass freely through the transparent film and glass. Without voltage, the liquid crystals do not line up in rows. This diffuses the light, making the glass appear opaque or obscure. FORMED GLASS POLYMER-DISPERSED LIQUID CRYSTAL PRIVACY GLASS 7.124 a nozzle. Different degrees of coarseness are used to achieve varying levels of smoothness. The resulting granular-textured surface is susceptible to the absorption of oils. Fingerprints and dirt are typically visible on sandblasted surfaces unless treated with an applied sealer. The sandblasted surface may be protected by enclosing it within an insulated double-glazing unit. CAST GLASS Cast glass, also known as molded glass, is formed in molds, using combinations of colors and textures to create the desired product. Cast glass may be molded to precise dimensions and tolerances, or it may be formed into art glass units. The casting process allows an unlimited number of glass forms, colors, and textures to be created. Thicknesses and overall sizes are dependent on the design and intended use for the cast glass. Cast glass products include glass tiles, stair treads, countertops, artwork, and glass panels. SURFACE TEXTURES Surface textures on glass soften transmitted light, add decorative designs, increase obscurity for privacy, or lightly fracture the glass surface for a frosted effect. Surface-texturing processes can be applied to clear, tinted, or reflective glass, prior to tempering. SANDBLASTING Sandblasting is used to create a translucent frosted effect of a desired design on the glass surface. The glass is blasted with small abrasive particles of sand and high-pressure air projected through One-way mirrors are used for discreet observation, such as in lineup rooms in law enforcement facilities. These mirrors are created by the use of a special reflective coating, which allows approximately 12% transmission and is reflective to the side with the highest light intensity. Light on the observation side is reduced by a 10:1 ratio, which maintains the reflective differential. One-way mirrors should be installed according to the manufacturer’s instructions, and the lighting should be coordinated to provide secure one-way visibility. FIRE-RATED GLASS Fire-rated glass is a transparent ceramic product. It can be used in fire-rated partitions, in larger areas than typically permitted for wire glass. Fire-rated glass may be polished, unpolished, or patterned (obscure). Fire-rated or fire/impact-safety-rated insulated glass units (IGUs) are composed of fire-rated glass and either tempered or annealed float glass. These units are available in tinted, low-E, reflective, one-way mirror, and art glass units. Fire-rated and impact-safety-rated glazing is available that has an intumescent gel layer between two panes of glass. When exposed to heat and light, the gel layer turns opaque and blocks the transfer of radiant heat through the glass for a short period of time. CUTTING AND EDGE TREATMENTS POLISHED EDGES Polished edges are created either by machine or by hand, using progressively finer sanding grits with a final polishing with a cork belt impregnated with a polishing compound. If the glass is to be tempered, the sharp shoulders of the edge are sanded, or seamed, to remove small cutting nicks, chips, and sharpness. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 127 INT E R IO R CONSTRUCTION COMPONENTS BEVELED EDGES Beveled edges on glass surfaces change the reflection angle of the light and give a framed appearance to the glass. Bevels are ground onto the face of the glass with a succession of diamond grinding and polishing wheels. Beveled glass is tempered with the bevel side down toward the horizontal rollers. INTE R I O R CO N ST RU CT I O N 127 RATED CORRIDOR GLAZING 7.127 WATERJET CUTTING Waterjet cutting is a precise computer-controlled glass-cutting method. High-velocity water is forced through a small ceramic nozzle, combined with a fine abrasive used as a cutting medium. It is capable of cutting through multiple layers of glass and is useful when dissimilar materials such as metals are nested together with the glass. INTERIOR GLAZING CODE REQUIREMENTS The IBC requires the use of safety glazing in hazardous locations. Hazardous locations are those subject to human impact, such as glass in doors, shower and bath enclosures, and glass sidelights in partitions. Generally, tempered glass and laminated glass are considered safety glazing. GLAZED PANEL REQUIREMENTS 7.128 GLAZING IN CORRIDORS • Fire-protection-rated glazing includes 1/4 in. (6 mm) wire glass set in steel frames and approved glass block. When this type of glazing is used, the total area of glass cannot exceed 25% of the area of the common wall separating two spaces or rooms. • Fire-resistance-rated glazing includes products such as clear ceramics, tempered glass, and insulated glass. These products carry various fire ratings of up to two hours and are tested as part of a wall assembly. The 25% limitation does not apply to these types of products, although each manufacturer’s product may have size limitations based on the fire rating of the product. SECURITY GLAZING APPLICATIONS Security glazing is composed of multiple layers of glass and/or polycarbonate plastic laminated together. Depending on the degree of security protection required, thickness can range from 3/8 in. (10 mm) to approximately 2-1/2 in. (64 mm). Security glazing is subject to size limitations. Both types of glazing must have a label or other identification permanently affixed showing the manufacturer’s name, test standard, and fire protection rating. SECURITY TELLER WINDOW 7.129 Source: National Fire Protection Association, Quincy, Massachusetts. GLAZING CONDITIONS 7.126 7.126 The most common situations where safety glazing is and is not required are shown in figure. The IBC should be consulted for other conditions and exceptions. 7.127 a. Glazed panel assemblies in fire-rated walls must conform to the size limitations indicated in figure and to wire glass and other approved material requirements. b. Multiple panels are permitted, but the aggregate area of all panels and openings must not exceed 25% of the wall surface. Requirements for glazing in doors are as follows: • If wire glass is used, size limitations apply, based on the fire door rating. Fire-resistance-rated glazing may be used, including ceramic, special-tempered, and insulated glass. These products do not have size limitations, except for those developed during manufacturer’s testing. • For most interior work, a 20-minute-rated door is required when used in a one-hour fire-resistance-rated partition used as an exit access corridor wall, and a 3/4-hour-rated door is required when used in a one-hour partition other than a corridor wall. Both doors require gasketing for draft and smoke control. The IBC covers glazing in corridors. When corridor walls are required to have a one-hour fire-resistive rating, any glazing in the corridor wall must meet the requirements for interior fire window assemblies. The allowable amount of glass depends on which type of glass is used—fire-protection-rated glazing or fire-resistancerated glazing: NOTES GLAZING IN DOORS Contributors: Robert Thompson, AIA, Creative Central, Tigard, Oregon. Jana Gunsul, AIA, DES Architects & Engineers; Redwood City, California. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 128 I N T E R IO R CO NST RU CTION FIXED WINDOWS AND STOREFRONTS FRAMED GLAZING DETAILS 7.130 Page 128 INTERIOR CONSTRUCTION CO MPO N E N T S FRAMELESS GLAZING DETAILS 7.131 ART GLASS WALL Art glass can be incorporated into room dividers in such interior spaces as restaurants, hotel lobbies, and residences. The designer typically works with the artisan who fabricates the glass. The artisan may also install the glass into the wall to ensure proper handling and support. ART GLASS WALL—SECTION 7.132 Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 129 INT E R IO R CONSTRUCTION COMPONENTS ART GLASS WALL—ELEVATION 7.133 INTE R I O R CO N ST RU CT I O N 129 OPERATING WINDOWS DEFINITIONS • Borrowed light: An interior wall opening or window that allows light to be transferred into another space • Clerestory: The portion of a wall above an adjacent roof level; also, a fixed or operable window located in this part of a wall • Dormer: A vertical window set above the line of a sloped roof in a small projecting space with triangular side walls • Internal dormer: A vertical window set below the line of a sloped roof • Mullion: A slender vertical member separating lights, sashes, windows, or doors • Muntin: A nonstructural member separating panes within a sash; also called glazing bar or sash bar • Oriel window: A bay window supported by brackets, corbelling, or cantilevers • Ribbon window: A horizontal band of fixed or operable windows extending across a significant portion of the facade • Sash: The basic unit of a window, consisting of frame, glazing, and gasketing; may be stationary or operable • Window wall: A continuous series of fixed or operable sashes, separated by mullions that form an entire non-load-bearing wall surface WINDOW EGRESS REQUIREMENTS When required for egress, such as in sleeping areas in residences, windows must meet the following criteria: 1. Clear opening per sash must be a minimum of 5.7 sq ft (0.5 sq m). 2. Bars, grilles, or screens must be releasable from inside without use of tools or key. 3. Windows opening onto fire escapes have additional requirements; refer to codes. 4. Check with manufacturers for integral release hardware options for awning, casement, pivot, or other windows. 5. Double-hung window units with fully removable sash that do not require special tools, force, or knowledge to operate may offer greater flexibility in unit selection to meet size requirements for egress openings; verify with manufacturers and code officials. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 130 I N T E R IO R CO NST RU CTION Page 130 INTERIOR CONSTRUCTION CO MPO N E N T S WINDOW TYPES AND FRAMES WINDOW OPERATION TYPES 7.134 PARTS OF A WINDOW 7.135 WINDOW EGRESS REQUIREMENTS 7.136 Source: National Fire Protection Association, Quincy, Massachusetts. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 131 INT E R IO R CONSTRUCTION COMPONENTS RESIDENTIAL WOOD WINDOW HEAD DETAIL 7.137 RESIDENTIAL WOOD WINDOWSILL DETAIL 7.139 INTE R I O R CO N ST RU CT I O N 131 HINGED SWINGING DOOR 7.140 SLIDING POCKET DOOR 7.141 RESIDENTIAL WOOD WINDOW JAMB DETAIL 7.138 INTERIOR DOORS SELECTION AND SPECIFICATION OF INTERIOR DOORS Basic interior door types include hinged swinging, sliding pocket, folding, pivoted, bypass, and accordion doors. Standard materials for interior doors include solid core and hollow wood, hollow metal (steel), aluminum, and glass. Interior doors can be sophisticated, complicated pieces of equipment. For example, automatic doors require power mechanisms and controls; acoustical doors often use automatic door bottoms that seal the door undercut as the door is closed; a coordinator may be required to ensure that the inactive leaf of a pair of doors closes before the active leaf. Consultants are often required to ensure the proper selection and specification of interior doors. TYPES OF DOORS HINGED SWINGING DOORS Hinged swinging doors are the most common type of door. They are easy to install and the most convenient type of door to use but require space for the door swing. They are available in a wide range of materials and finishes, with multiple hardware options. Fire-rated hinged swinging doors are available. Edges are easily sealed to prevent the passage of smoke, light, or sound. SLIDING POCKET DOORS A sliding pocket door is hung on a track and slides into a space within the width of the partition. No operating space is required for a door swing. Sliding pocket doors are relatively inexpensive. However, they are awkward for frequent use, difficult to seal against light or sound, and cannot be used as an exit door. Contributors: John F. Kaulbach, AIA, Kling, Philadelphia, Pennsylvania. John Carmody, University of Minnesota, Minneapolis, Minnesota. Stephen Selkowitz, Lawrence Berkeley National Laboratory, Berkeley, California. Daniel F. C. Hayes, AIA, Washington, DC. SLIDING POCKET DOOR DETAIL 7.142 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 132 I N T E R IO R CO NST RU CTION Page 132 INTERIOR CONSTRUCTION CO MPO N E N T S FOLDING DOORS BYPASS DOORS BIFOLD DOORS A folding door consists of hinged door panels that slide on an overhead track. This uses minimum operating space. Folding doors are often used as closet doors or as a visual screen to other spaces. They may be awkward to use and cannot be used as an exit door. Lower quality folding doors are prone to jumping their tracks. Bypass doors are hung on a track; heavy doors may slide on a track in the floor. No operating space is required. Bypass doors are generally used for closet doors. They are difficult to seal, awkward for frequent use, and cannot be used as an exit door. Bifold doors are wood or metal door pairs hinged together with pivots at the jamb. Track-guided hangers/trolleys allow the doors to fold against each other when they open. Lower quality bifold doors may tend to jump their tracks. Bifold doors require less floor space than swing doors, but the thickness of the door panels reduces the clear opening. FOLDING DOOR 7.143 PIVOTED DOORS Pivoted doors are center hung or offset hung, or balanced pivot hardware may be required. Center-hung pivots allow the door to swing in both directions. This style minimizes the appearance of hardware, especially if center-hung pivots are used. Pivoted door hardware has the capacity to support a large, heavy door. Balanced doors require less space to operate and take less effort to open. They may be used for concealed doors. PIVOTED DOOR 7.144 BYPASS DOOR 7.145 BIFOLD DOOR 7.147 SURFACE SLIDING DOORS Surface sliding doors, such as barn doors, slide on the surface of a partition. They are used in offices with movable walls and for meeting rooms where a wider opening is desired and where the door remains open or closed for longer periods of time. Hardware for doors that are hung on the wall surface and mounted to slide across an opening is variously called barn door, industrial, sliding, or heavy-duty door hardware. Flat-track barn door hardware consists of a wheel mounted on a strap that curves over a horizontal surface-mounted track. Barn door hardware is used for barns and stables but comes in a variety of designs that are suitable for office and residential use. Some surface sliding door systems come with floor-mounted rollers. Ceiling- and soffit-mounted systems are available, some with curved tracks. OTHER DOOR TYPES Other door types include overhead coiling and revolving doors. Performance-based interior door types that are integrated into openings of compatible performance include fire-rated, acoustical, security, and ballistic threat-resisting doors. Storefront, automatic-opening, and overhead coiling doors are commonly provided as complete systems that are integrated into the design. DOOR HANDING FLAT-TRACK BARN DOOR HARDWARE 7.146 The hand, or the handing, of a door refers to the standard method of describing the way a door swings. Handing is used in the industry to communicate how a door swings and the kind of hardware that must be supplied for a specific opening. Some hardware is specific to the hand of the door due to the bevel on the strike side of the door. Hardware that works on any hand of door is called reversible or nonhanded. Handing is determined by standing on the outside of the door looking at the door. If the door hinges on the left and swings away, it is a left-hand door. The corridor side is considered the outside of a room door, as is the lobby side of a door opening into a room or the room side of a closet door. When the distinction between outside and inside is not clear, the outside is considered the side of the door where the hinge is located. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 133 INT E R IO R CONSTRUCTION COMPONENTS DOOR HANDING 7.148 DOOR-OPENING COMPONENTS 7.149 WOOD STOPS 7.150 DOOR OPENINGS Most swinging doors arrive from the manufacturer with the door frame included. However, doorways may be left open without a door, or doors may be retrofitted into existing openings. The framing of the doorway provides support for the door and its opening. The trim (casing ) covers frame components and the edges of finish materials, and supports the style of the space. INTE R I O R CO N ST RU CT I O N 133 The single-acting door, the most common door type, has a leaf that operates in a swinging or sliding motion in only one direction. Double-acting doors have a leaf that operates in two directions. There is usually no stop present to restrict the motion of the door, but when the door does have a stop, it can be released mechanically to permit access in an emergency. FRAME OPENING TYPES 7.151 A balanced door is a single-action swinging door mounted on offset pivots. The leaf operates independently of the jamb, and the elliptical trajectory of the leaf requires less clear floor space than a conventional swinging door. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 134 I N T E R IO R CO NST RU CTION SINGLE-ACTING DOOR 7.152 DOUBLE-ACTING DOOR 7.153 Page 134 INTERIOR CONSTRUCTION CO MPO N E N T S DEFINITIONS • Casing : The finished, often decorative framework around a door opening • Double-egress door : A pair of doors within a single special frame that swing in opposite directions to allow emergency egress from either side; typically used where a fire or smoke partition crosses a corridor • Fire-door assembly : Any combination of a fire door, frame, hardware, and other accessories that together provide a specific degree of fire protection • Fire exit hardware : Panic hardware that is listed for use on firedoor assemblies • Head : The horizontal portion of a door frame above the door opening • Jamb : The vertical members at the sides of a door opening • Labeled: Equipment, products, or materials marked with the label, symbol, or other identifying mark of an approved testing organization that indicates compliance with standards for manufacture and testing • Listed : Equipment, devices, materials, or services included in a list published by a testing agency that have been shown to meet applicable standards for use in fire-rated assemblies or that have been tested and found suitable for use for a specified purpose • Panic hardware : A door-latching assembly incorporating a device that releases the latch upon the application of a force in the direction of egress travel • Prehung door : A door and frame combination fabricated and assembled by the manufacturer and shipped to the site • Sill : The horizontal members at the bottom of a door opening • Undercut : The space between the bottom edge of a door and the sill or threshold PARTS OF A DOOR 7.156 DOOR NOMENCLATURE 7.155 ACCESSIBILITY REQUIREMENTS BALANCED DOOR 7.154 Door accessibility requirements are outlined below. For more information, consult the A2010 ADA Standards for Accessible Design and ICC/ANSI A 117.1, Accessible and Usable Buildings and Facilities, for additional requirements. • For opening width compliance, use doors 3 ft (914 mm) wide. • Kick plates are recommended on outside surface of doors along accessible routes. • Maximum opening force for interior hinged doors, sliding, and folding doors is 5.0 lb (22.2 N). Minimum opening force for fire doors is regulated by the local authority having jurisdiction. • Door closing speed must be a minimum of five seconds from an open position of 90° to an open position of 12°. CLEAR WIDTH OF ACCESSIBLE DOORWAYS 7.157 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 135 INT E R IO R CONSTRUCTION COMPONENTS ACCESSIBLE DOOR FEATURES 7.158 STANDARD DOOR AND DOOR CLEARANCE 7.160 INTE R I O R CO N ST RU CT I O N 135 DOOR SIZES Both wood and hollow metal doors are available in a variety of standard widths. Custom doors can be made in any size, but, in general, it is best to specify standard-width doors and vary the height when ordering custom sizes. Most door manufacturers do not offer a warranty if maximum heights are exceeded. STANDARD DOOR SIZES 7.161 ACCESSIBLE DOOR 7.159 WOOD DOORS FACE MATERIAL Wood doors are available with face materials of wood veneer, composite veneer, high-density plastic laminate, medium-density overlay, and hardboard. Veneers may be rotary cut, plain sliced, quarter sliced, or rift cut, and may be matched with random, slip, and book-matched methods. • Composite veneers are manufactured by slicing sustainably grown hardwoods and then vat dying and pressing them into new, composite manufactured logs. The composite logs are then sliced to form new veneers that replicate other natural woods. By using various colors of natural veneers and slicing angles of the composite log, a nearly unlimited number of simulated wood species and veneer patterns can be created. These veneers can be applied to doors in the same way as natural veneers. • Plastic laminate veneers provide a durable surface with hundreds of available colors and patterns. • Medium-density overlay (MDO) faces are used to provide a smooth, paintable surface that resists grain raising and moisture. For this reason, they are often used for exterior doors. • Hardboard is used with three-ply construction for interior doors that are to be painted and as a lower-cost option to MDO. CORE TYPES Hollow-core doors are typically used in residential construction and for commercial doors subject only to light use. Institutional hollow-core doors, with heavier stiles and rails and with additional blocking, have increased strength and resistance to warping, but may cost as much as some solid-core doors. Solid-core doors are more secure, more durable, more resistant to warping, and allow less acoustical transmission. They are used in most institutional and commercial projects. Contributors: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Daniel F. C. Hayes, AIA, Washington, DC. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 136 I N T E R IO R CO NST RU CTION HOLLOW CORE 7.162 Page 136 INTERIOR CONSTRUCTION CO MPO N E N T S PARTICLEBOARD CORE 7.163 MINERAL COMPOSITION CORE 7.164 WOOD DOOR TYPES Wood door types include flush, panel, sash, louvered, Dutch, and French. Flush doors are the most common type for both commercial and residential work. Dutch doors are designed so that the top half can open while keeping the bottom closed, and may have a transaction shelf. Louvered doors permit air to circulate, but also allow sounds to pass. French doors are often used in pairs at residential patios. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 137 INT E R IO R CONSTRUCTION COMPONENTS WOOD DOOR TYPES 7.165 INTE R I O R CO N ST RU CT I O N 137 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 138 I N T E R IO R CO NST RU CTION STILE AND RAIL DOORS Panel doors consist of a framework of vertical (stile) and horizontal (rail ) members that hold solid wood or plywood panels, glass lights, or louvers in place. Page 138 INTERIOR CONSTRUCTION CO MPO N E N T S STILE AND RAIL—RAISED PANEL 7.168 WOOD SLATS 7.169 The doors are made of solid or built-up stiles, rails, and vertical members (muntins ), typically doweled according to applicable standards. Stock material includes ponderosa pine, fir, hemlock, or spruce and hardwood veneers. Hardboard, metal, and plastic facings are available in various patterns. STILE AND RAIL TERMINOLOGY 7.166 DOOR GLAZING Most building codes require all glass in doors to be safety glazed. Insulated safety glazing is available for increased thermal or acoustical performance. Glazing core and edge strip materials are similar to those used in flush doors. Face veneer is typically hardwood at 1/8 in. (3 mm) minimum thickness. Typical profiles used for glazing trim work include cove, bead, or ovolo. PANELS Flat panels are typically three-ply hardwood or softwood. Raised panels are constructed of solid hardwood or softwood built up of two or more plies. Doors 1 ft 6 in. (457 mm) wide or less are one panel wide. STILE AND RAIL DOOR DETAILS 7.167 SINGLE-RABBET FRAME WITHOUT CASING 7.170 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 139 INT E R IO R CONSTRUCTION COMPONENTS HIDDEN DOOR 7.171 HOLLOW METAL DOORS DOOR TYPES Hollow metal doors are doors constructed from sheet steel attached to various types of cores. They are used in steel frames, also constructed of sheet steel bent into various profiles. HOLLOW METAL DOOR CONSTRUCTION—FULL FLUSH 7.174 INTE R I O R CO N ST RU CT I O N 139 STANDARD HOLLOW METAL DOOR SIZES 7.176 STANDARD HEIGHTS STANDARD WIDTHS 1-3/4-IN. (44 MM) DOORS 1-3/8-IN. (35 MM) DOORS 2-0 (610 mm) 6-8 (2,032 mm) 6-8 (2,032 mm) 2-4 (711 mm) 7-0 (2,134 mm) 7-0 (2,134 mm) 2-6 (762 mm) 7-2 (2,184 mm) 7-2 (2,184 mm) 2-8 (813 mm) 2-10 (864 mm) 3-0 (914 mm) 3-4 (1,016 mm) 3-6 (1,067 mm) 3-8 (1,118 mm) 3-10 (1,168 mm) 4-0 (1,219 mm) 7-10 (2,388 mm) 8-0 (2,438 mm) STEEL DOOR TYPES 7.177 SLIDING POCKET DOOR 7.172 HOLLOW METAL DOOR CONSTRUCTION—SEAMLESS 7.175 BYPASS DOOR 7.173 STANDARD HOLLOW METAL DOOR SIZES Custom doors can be manufactured to nearly any practical size; however, standard widths should be used whenever possible. NOMENCLATURE LETTER SYMBOLS F T E TE L LL V VL Contributor: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Flush Textured Embossed Textured and embossed Louvered (top or bottom) Louvered (top and bottom) Vision light Vision light and louvered N NL GL G Narrow light Narrow light and louvered Half glass and louvered Half glass (several options available) FG Full glass FG3 Full glass, three panes FL Full louver D Dutch door 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 140 I N T E R IO R CO NST RU CTION Page 140 INTERIOR CONSTRUCTION CO MPO N E N T S STANDARD STEEL DOOR GRADES AND MODELS 7.178 FULL FLUSH OR SEAMLESS LEVEL 1 TYPE Standard duty MODEL MSG NO. IP INCHES SI MM 1 20 0.032 0.8 Full flush 18 0.042 1.0 Full flush 16 0.053 1.3 Full flush 2 2 Heavy duty 1 3 Extra heavy duty 1 Seamless 2 Seamless 2 Seamless 3 4 Maximum duty 1 CONSTRUCTION Stile and rail 14 0.067 1.6 2 Full flush Seamless Source: SDI-108, Steel Door Institute, Cleveland, Ohio. CORE CONSTRUCTION Four types of cores are commonly used for hollow metal doors: honeycomb, steel stiffeners, foam plastic, and mineral board: STANDARD HOLLOW METAL FRAMES 7.179 • Honeycomb cores: These are made from heavy kraft paper formed into hexagonal cells ranging from 1/2 in. (13 mm) to about 1 in. (25 mm) in size. The core is impregnated with phenolic resin to resist moisture, mildew, and vermin. • Steel-stiffened cores: These are used in doors as vertical stiffeners spaced between 4 and 6 in. (102 and 152 mm). Cavities in between are usually filled with fiberglass insulation. Steel-stiffened cores are used primarily for exterior doors, where high rigidity is important. • Foam plastic cores: These cores are filled with either polystyrene or polyurethane, both highly insulating material. Polystyrene is used for typical exterior doors, and polyurethane is used where extreme protection from frigid cold is important. Both insulation types melt at relatively low temperatures, which may prevent using a factory-applied, hot baked-on paint system. • Mineral cores: These are constructed with a fire-resistive material similar to gypsum board. Mineral cores are used on labeled doors where a temperature-rise limit is required. HOLLOW METAL FRAMES FRAME TYPES Door frames can be factory or field assembled. All frames must be adequately anchored at the jambs and floor according to the manufacturer’s specifications. Light-gauge metal frames are constructed of head and jamb members, with or without a transom panel, of aluminum (45-minute maximum rating) or light-gauge steel (1.5-hour maximum rating). They consist of a single frame that slips over the partition. Separate casing trim pieces are then snapped onto the edges of the frames. These frames are available in 18-, 20-, and 22-gauge thicknesses. Pressed steel (hollow metal ) frames have head and jamb members, with or without solid or glazed transoms or sidelights, of 18gauge or heavier steel (3-hour maximum rating). This frame is required for most metal doors. Steel frames are generally made from one piece of sheet steel bent into the required profile in either a double-rabbet or a single-rabbet configuration. These frames are available in 12-, 14-, 16-, and 18-gauge thicknesses. BUTT AND WRAPAROUND FRAMES For butt or flush frames: • Use anchors appropriate for the type of wall construction; a minimum of three per jamb is required. • Grout frame with mortar or plaster as used in wall. • Caulk frame at wall. • Trim may be used to cover joint at wall line. BUTT FRAME/FLUSH FRAME 7.180 NOTE 7.178 Stiles and rails are 16 gauge; flush panels, when specified, are 18 gauge. 7.180 Dimension A is a minimum of 3 in. (76 mm) in area of pull or knob hardware. Check dimension B on hinge side for door swing greater than 90°. For wraparound frames, the basic wall dimension is less than the throat opening dimension. Use anchors appropriate for the type of wall construction; a minimum of three per jamb is required. Fill the frame with mortar or plaster as used in the wall. Grout a frame installed at a masonry wall. WRAPAROUND FRAME 7.181 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 141 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 141 STOREFRONT FRAMING STANDARD STEEL FRAME 7.182 Storefront framing consists of extruded aluminum sections assembled to form door and glazed openings. It is similar to aluminum door frames and partition systems, except it is designed for exterior applications and does not accommodate gypsum wallboard partitions. It is often used for interior applications if exterior framing has to be matched or when partition system framing does not provide the necessary size, finish, or profiles available in storefront systems. The height of entrance doors is typically 7 ft (2,134 mm). Typical door widths are 3 ft (914 mm), a pair of 2 ft 6 in. (762 mm), and a pair of 3 ft (914 mm). ALUMINUM DOOR FRAMES AND PARTITIONS used as part of a partition system that includes sidelight framing, partition supports, and base trim. Aluminum door frames and partition systems are often used in place of wood or hollow metal frames because of their crisp, sharp corners and available finishes or because they can match the shape and finish of exterior storefront or curtain wall systems. Aluminum door frames can be used alone, but are most typically Aluminum door frames and interior window framing can be used in standard metal stud framed walls. Some manufacturers integrate them into a demountable or movable partition system, where prefinished gypsum wallboard panels are attached to aluminum tracks and connectors. TYPICAL ALUMINUM FRAME 7.183 Contributor: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 142 I N T E R IO R CO NST RU CTION Page 142 INTERIOR CONSTRUCTION CO MPO N E N T S GLASS DOOR PARTS 7.185 TYPICAL STOREFRONT 7.184 GLASS DOOR SECTION 7.186 GLASS DOORS Glass doors are constructed primarily of glass, with fittings to hold the pivots and other hardware. Their strength depends on the glass rather than on the framing. Glass doors are generally constructed of 1/2- or 3/4-in. (13 or 19 mm) tempered glass. Glass doors may be installed within an opening or as part of an allglass entrance system. If used alone, glass doors may be set within a wall opening with or without a frame, or they can be installed between glass sidelights. The same type of fitting used on the door is generally used for the sidelights. Although jamb frames of aluminum, wood, or ornamental metal can be used, they are not necessary, and the glass sidelights can be butted directly to the partition. The minimum configuration for a glass door requires some type of door pull and a corner fitting at the top and bottom (sometimes called the shoe) to hold the pivots. Some manufacturers provide hinge fittings that clamp on the glass and support the door in much the same way as a standard hinged door. If the door is used for egress, the local building code may require the use of special hardware that allows the door to be locked from the outside, but still allows the door to be unlatched and opened from the inside with a single push on a push bar. Glass doors are heavy and may require a power operator or a balanced door system. ALL-GLASS ENTRANCES All-glass entrances, commonly used for interior storefronts, include glass doors and surrounding glazing that does not use visible framing members. Instead, special fittings are used to clamp adjacent glass pieces together and to support the glass doors. The glass, typically 1/2 or 3/4 in. (13 or 19 mm) thick, is installed in channels set in the floor and above the ceiling. Glass fins, for additional lateral support, may be placed perpendicular to the main glass plane and attached with silicone sealant. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 143 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 143 OTHER DOOR TYPES GLASS DOOR INSTALLATIONS 7.187 AUTOMATIC DOORS Automatic door operators open and close doors upon activation of a manual or automatic device. They are commonly used for accessible entrances and other doors where hands-free operation is desired. They can control swinging, sliding, and folding doors. MANUAL ACTIVATION Manual activation devices include push-buttons, push plates, pull cords, radio controls, and elbow switches. These are available as inset- or surface-mounted controls. Elbow switches should be mounted 43 in. (1,092 mm) above the floor. AUTOMATIC ACTIVATION Automatic devices use photocells, contact mats, or motion detection equipment. Photocells detect the interruption of a light beam near the door and direct the controls to open the door. Contact mats are surface mounted or recessed in the floor in front of the door. Pressure exerted on the mat activates the door-opening controls. When mats are used for double doors, a safety mat should be used on the swing side of the doors. Motion detection equipment uses microwaves or infrared beams to detect movement and the presence of people. Automatic door operators may be used to open standard wood or metal doors provided by another manufacturer, or may be supplied as a complete package that includes doors, operators, controls, and other accessories. GLASS DOOR CONFIGURATIONS 7.188 Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Tom Bader, AIA, Wheeler Kearns Architects, Chicago, Illinois. TYPICAL ALL-GLASS ENTRANCE 7.189 AUTOMATIC DOOR 7.190 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 144 I N T E R IO R CO NST RU CTION DOOR HARDWARE COMMON DOOR HARDWARE TERMS • Cylinder (of a lock) : A cylindrical-shaped assembly containing • • • • • • • • • • • • • the tumbler mechanism and the keyway, which can be actuated only by the correct keys Deadbolt (of a lock) : A lock bolt having no spring action or bevel, and which is operated by a key or turnpiece Door bolt : A manually operated rod or bar attached to a door, providing a means of locking Doorstop : A device to stop the swing or movement of a door at a certain point Electric strike : An electrical device that permits releasing of the door from a remote control Exit device : A door-locking device that grants instant exit when someone presses a crossbar to release the locking bolt or latch Flush bolt : A door bolt set flush with the face or edge of the door Lockset : A lock, complete with trim such as handles, escutcheons, or knobs Mortise : A cavity made to receive a lock or other hardware Mortise lock (or latch): A lock designed to be installed in a mortise rather than applied to the door’s surface Rabbet : The abutting edges of a pair of doors or windows, shaped to provide a tight fit Reversible lock : A lock that, by reversing the latch bolt, may be used for any door handing Rose : A trim plate attached to the door under the handle, sometimes acting as a handle bearing Strike : A metal plate or box that is pierced or recessed to receive the bolt or latch when projected; sometimes called the keeper Page 144 INTERIOR CONSTRUCTION CO MPO N E N T S A complete lockset for an entrance door handle includes a mortise lock, a handle outside, and a knob and rose inside. Accessible doors require lever hardware; knobs do not meet these requirements. Double push-pull bars may be used on the pull side of single-acting doors or on either side of double-acting doors. DOOR HARDWARE LOCATIONS 7.192 LATCH AND LOCK TYPES Based on use characteristics, there are four main types of latches and locks: • Passage: Latches can be operated by a handle from either side at all times. • Privacy: The outside handle is locked by a push-button inside (or if a deadbolt latch, by a turn) and unlocked by an emergency key outside. • Entry: The outside handle is made inoperative by mechanical means, other than a key, on the inside. The latch bolt is operated by a key in the outside handle or by manual means at the inside handle. • Classroom: The outside handle is locked from the outside by a key. When the outside handle is locked, the latch bolt may be retracted by a key from the outside or by rotating the inside handle. In all cases, the latch bolt can be operated by a handle from either side. A mortise bolt is a miniature deadlock, with the bolt projected or retracted by a turn of the small knob. Face the outside of the door to determine its hand. The outside of the door is the key side, or the side that would be secured should a lock be used. This would usually be the exterior of an entrance door or the corridor side of an office door. BOLT MECHANISMS 7.191 DOOR HINGES ELEMENTS OF A HINGE 7.193 DOOR OPENING HARDWARE DOORKNOBS, HANDLES, PLATES, AND BARS 7.194 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 145 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 145 FINISHES FOR ARCHITECTURAL HARDWARE LOCK TYPES 7.195 Metals commonly used in architectural hardware are brass, bronze, iron, steel, stainless steel, aluminum, and zinc. The properties of stainless steel, including rust resistance, easy maintenance, and high-luster finish, make it highly suitable for architectural hardware. Aluminum is often alloyed with other metals and can be used instead of cast iron for applications such as doorstops, handrail brackets, and hooks. Forged iron is often used for special decorative trim, such as early-American hand-forged pieces. When selecting metals and their finishes, factors to consider are rust resistance, durability, and appearance. • Natural finishes have the color of the base metal and are low luster (satin finish) or high luster (polished finish). • Antiqued and distressed finishes are used to give the appearance of an antique. • Oil-rubbed bronze produces a dark, oxidized finish. • Common plated finishes are chromium or brass, bronze, and nickel plating. Matching door hardware finishes with other components of a project may be required. One method to ensure a close match is to specify the actual metal alloy number to be provided for plated finishes, for example, UNS No. C32000 for brass (leaded red brass). This method is, however, more costly than using manufacturer’s standard finishes, and may not be available for some types of door hardware. Further, even if the metal alloy of a plated finish matches, if the underlying base metal is not the same, the finished appearance will be slightly different. Whether you are matching finishes or just referencing Builders Hardware Manufacturers Association (BHMA) finish numbers, verify the actual finish by requesting samples from manufacturers. Match plate samples for some finishes are available from BHMA. DOOR CLOSERS When properly installed and adjusted, a door closer should control the door throughout the opening and closing swings. It combines three basic components: PRIVACY LOCK 7.196 For lavatory or other privacy doors: • Either lever operates latch bolt (except when outside lever is locked by inside push-button). • Button automatically releases by turning inside lever or closing door. • Door can be unlocked, when necessary, by operating outside turn button. • No emergency key is required. • Inside lever is always active. Contributors: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. DOOR CONTROL Door control, in the main, involves locks such as the following: • Electric strike: This lock provides remote release of a locked door without retracting the latch bolt by releasing the electric strike lip, sometimes called a keeper or gate. When the door closes, the beveled latch bolt rides over the lip and falls into the strike pocket. Keeping the handle on the secure side free to turn allows free egress from that side. • Electrified mortise lock: This is a standard mortise lock that has been modified so that the ability to turn the handle can be controlled electrically. The unsecure side of the door can be electrically or manually controlled. • Electromagnetic locks: There are two varieties of electromagnetic locks: standard and shear. The standard electromagnetic lock can only be used on doors that swing in one direction. Electromagnetic locks fail safe (unlock when not powered) and provide a holding force of 600 to 1,650 lb (272 to 748 kg). A shear lock is an electromagnetic lock fully concealed in the door and header or frame. It can be used on bidirectional doors. It fails safe and has a holding force of up to 2,700 lb (1,225 kg). • Electrified exit devices (panic bars): These are standard panic bars modified to allow electrical control from the unsecured side. They are manufactured with a rim device, a mortise lock, or a vertical rod device. Vertical rod devices are typically used where there is no mullion to accept a latch bolt. The secure side must always be mechanical, to allow unimpeded egress, or have a release mechanism nearby. • A power source, to close a door • A checking source, to control the rate at which the door closes • A connecting component such as an arm that transmits the closing force from the door to the frame Additional features also available in many types of closers include back check, delayed action, adjustable spring power, and a variety of hold-open functions (regular, fusible link, and hospital). A full range of closer sizes are available to suit various door dimensions, locations, and job conditions. The manufacturer’s recommendations should be considered carefully. Closers with delayed-action features give a person more time to maneuver through doorways. They are particularly useful on frequently used interior doors such as entrances to toilet rooms. The ADA/ABA Accessibility Guidelines require a closing speed of at least 3 seconds; ANSI requires 5 seconds. Adjustable speed controls are available. Door closers may be surface mounted or concealed in the door, frame, or floor. There are three places to mount surface closers: hinge side, parallel arm, and top jamb. A wide variety of brackets, including corner and soffit types, are available to meet varying door and frame conditions. Surface-mounted and concealed-in-door closers are used exclusively for single-acting doors; floor closers and frame-concealed closers may be used for either single- or double-acting doors. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 146 I N T E R IO R CO NST RU CTION MODERN-TYPE SURFACE-MOUNTED DOOR CLOSER 7.197 Page 146 INTERIOR CONSTRUCTION CO MPO N E N T S CONCEALED DOOR CLOSERS 7.198 EXIT DEVICES Door exit devices are characterized by a bar across the width of the door’s interior surface, which reacts to pressure from an exiting person. They are designed to allow a person egress without the use of hands. Exit devices can be designed to lock on the exterior and to sound an alarm when opened from inside. Panic hardware is a door-latching assembly that incorporates a device that releases the latch upon the application of a force in the direction of egress travel Fire exit hardware is panic hardware that is listed for use on fire-door assemblies. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 147 INT E R IO R CONSTRUCTION COMPONENTS INTE R I O R CO N ST RU CT I O N 147 PANIC HARDWARE 7.199 THRESHOLDS Threshold profiles vary among manufacturers. The standard length is 18 to 20 ft (5.5 to 6 m), or thresholds may be cut to size. A 1/4or 1/2-in. (6- or 13-mm) offset allows a lower exterior surface and resulting improved resistance to water penetration. Assembled thresholds combine components to allow saddles to be made to any width; joints will not show, as the fluting pattern is identical. TYPICAL ASSEMBLED THRESHOLDS 7.201 LEVEL BEARING THRESHOLD 7.200 ACCESSIBLE THRESHOLDS Level changes at thresholds up to 1/4 in. (6 mm) may be vertical, without edge treatment. Level changes between 1/4 and 1/2 in. (6 and 13 mm) must be beveled with a slope no greater than 1:2. An abrasive finish is recommended for the threshold surface. Thresholds are typically limited to 1/2-in. (38-mm) maximum heights. However, some standards allow a 3/4-in. (19-mm) height beveled at a 1:2 maximum slope for existing or altered thresholds and patio sliding doors in some dwelling units. Contributors: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. Tim Shea, AIA, Richard Meier & Partners Architects, Los Angeles, California. ACCESSIBLE THRESHOLDS 7.202 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 148 I N T E R IO R CO NST RU CTION THRESHOLDS AT CERAMIC TILE FLOOR 7.203 Page 148 INTERIOR CONSTRUCTION COMPO N E N T S BOTH DOORS SWINGING IN 7.206 • Pedestal systems are composed of either a threaded rod or a telescoping tube, which supports the panel at the corners (or at the edge of the floor perimeter). It is considered good practice to adhere pedestal bases to the subfloor to resist horizontal forces. This system can be adjusted to accommodate a lowheight requirement similar to the low-profile system described previously. There are two basic types of pedestal systems: stringerless and stringer systems. STRINGERLESS SYSTEMS Stringerless systems consist of pedestals located so that each pedestal head supports four panels at one of their corners. Stringerless systems provide maximum access to the underfloor cavity. Stringerless understructures can be less stable laterally than those with stringers and are less capable of withstanding lateral forces from earthquakes and other sources. DOOR OPENINGS FOR MEANS OF EGRESS Doors that can be used as a means of egress include the following: ENTRANCES AND VESTIBULES ACCESSIBLE ENTRANCES According to the ADA/ABA Accessibility Guidelines 2004, revolving doors are not allowed to be part of an accessible route. The distance between two hinged or pivoted doors in series, as in an entry vestibule, are required to be a minimum of 48 in. (1,220 mm) plus the width of the doors swinging into the space. DOORS SWINGING IN SAME DIRECTION 7.204 Two panel types are available for stringerless pedestal systems: gravity-held and bolted-down panels. RAISED FLOOR AT PERIMETER 7.207 • Revolving doors: These may be used if they do not supply more than 50% of the egress capacity and if the leaves collapse under opposing pressures with a resulting exit path at least 36 in. (914 mm) wide. At least one exit door must be located in close proximity. • Power-operated doors: These may be used if they can be opened manually in the event of a power failure with a maximum force of 50 lb (222 N). • Horizontal sliding doors: These may be used if they comply with eight criteria, including the capability to be operated manually in the event of a power failure with no special effort or knowledge. • Access-controlled doors: These may be used if they comply with six criteria. Refer to the IBC for additional information. • Security grilles: These may be used if they do not provide more than 50% of the required egress and if they remain open during the time the space is occupied. Refer to national, local, and accessibility codes for details. RAISED FLOOR CONSTRUCTION RAISED ACCESS FLOORS BOTH DOORS SWINGING OUT 7.205 Access flooring consists of panels and an understructure system. This system creates a chase underneath the floor for wires, cables, and, in some cases, an air distribution plenum. Access flooring systems are often used in general offices, data centers, computer rooms, and cleanrooms. Multilevel access flooring systems are available that incorporate two or more continuous cavities beneath the floor panels to house wireways and an air distribution plenum. Some of the benefits of an access flooring system are: ACOUSTICAL PERFORMANCE • Complete flexibility for air distribution and electrical/data connectivity • Improved energy efficiency and lower building operational costs due to the ease of reconfiguration • Greater end user productivity due to individual temperature control • Reduced construction time UNDERSTRUCTURES UNDERSTRUCTURE TYPES There are two types of access flooring understructures: low-profile systems and pedestal systems. • Low-profile systems provide a low-height access floor, typically less than 4 in. (102 mm). Spaced plastic or metal supports incorporate cable management systems and provide support at regular intervals across the panel. Typically provided by a furniture manufacturer, this system can be used in both new and existing buildings; however, it is most commonly used in existing buildings that are under renovation to minimize the effect on the finished floor to finished ceiling distance. Contributor: Daniel F. C. Hayes, AIA, Washington, DC. Jane Hansen, AIA, DeStefano & Partners, Chicago, Illinois. Sara Bader, Gensler, Chicago, Illinois. Tile Council of America, Inc., Anderson, South Carolina. Airborne sound transmitted from one room to another through the access flooring and the underfloor cavity is another consideration when selecting a panel type and assembly for partitioned areas requiring acoustical privacy. Currently, ASTM has formed a working group to create a draft document for testing sound transmission in access flooring assemblies, but it has not been released at this time. Standard finished floor heights are available from 6 to 36 in. (152 to 914 mm). Standard cornerlock pedestals are used to support floor panels for 6 to 30 in. (152 to 762 mm) finished floor heights by their corners. Perimeter pedestal heads support panels that are used against a perimeter wall, or where two different types of floors meet. Pedestal bases should be at least 16 in. (406 mm) square. Stringer grid patterns 2 by 2 ft (610 by 610 mm) provide the greatest accessibility for areas with frequent cable changes and additions. Grid patterns 2 by 4 ft (610 by 1,219 mm) and 4 by 4 ft (1,219 by 1,219 mm) are also available. Plenum dividers may be located anywhere under the panel due to the flat underside of the panel. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 149 INT E R IO R CONSTRUCTION COMPONENTS ACCESS FLOORING UNDERSTRUCTURE SYSTEMS 7.208 THERMAL AND MOISTURE PROTECTION INTERIOR JOINT SEALANTS Joint sealants occur at transitions between dissimilar materials and at junctures within long runs of similar materials to control cracking. Four sealant types are popular for use in interiors: • Silicone sealants are the most expensive and most durable and have the best movement capability, but they are too soft for use in floor joints. SEALANT JOINT TYPES 7.209 NOTE 7.208 Apply pedestal adhesive between perimeter head and cut panel. Contributors: Kelly Hannon, Gensler, Dallas, Texas. Sara Bader, Gensler, Chicago, Illinois. INTE R I O R CO N ST RU CT I O N 149 • Urethane sealants have good movement capability and cure harder than silicone. They resist penetration when used in floor joints. • Latex sealants are inexpensive and are often used in applications with little movement or exposure to moisture. • Synthetic rubber sealants are inexpensive, have good adhesion, and remain permanently tacky. They have little movement capability. MOVEMENT If movement is expected in the joint, a bond breaker rod or tape should be inserted under the sealant to prevent three-sided adhesion. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 150 I N T E R IO R CO NST RU CTION Page 150 INTERIOR F INISHES I N T E R IO R FINISH E S VISUAL DISPLAY SURFACES Board surfaces are made of resilient, hard-coated polyester mounted on an aluminum composite backboard. They are compatible with dry-erase markers, and are designed to be easy to clean. CHALKBOARDS AND MARKERBOARDS DRY-ERASE WALLCOVERINGS Porcelain-enamel markerboards and chalkboards are composed of a porcelain-enamel face sheet laminated to a stabilizing core material with a moisture barrier backing. The backing sheet can be aluminum foil, aluminum sheet, or galvanized steel sheet. The core material can be 1/4 in. (6 mm) thick hardboard, 3/8 in. (10 mm) thick particleboard, or fiberboard 3/8 or 1/2 in. (10 or 13 mm) thick. Aluminum or wood frames and chalk trays can be factory or field applied. Map rails and flag holders are also available. Standard sizes are a maximum of 48 in. (1,220 mm) high and 16 ft (4.8 m) long. Combination units that join markerboards, chalkboards, and tackboards in a variety of sizes and configurations within a unifying frame provide versatility in classrooms and meeting rooms. Dry-erase wallcoverings are available in 75 to 100 ft (230 to 305 m) flexible rolls 48 to 60 in. (1,220 to 1,525 mm) wide. A nonwoven polyester cellulose backing is laminated to a pigmented vinyl with a top surface of a thermoplastic film that permits it to be used as a markerboard with dry-erase markers. Ferrous powder can be added to the vinyl during the manufacturing process to produce a magnetic surface. A thin, self-adhesive version is recommended for resurfacing existing chalkboards for use as markerboards. INTERIOR SPECIALTIES Water-based and solvent-based paints that are made for use with dry-erase markers are available in white and other colors. Acrylic latex chalkboard paint for use with chalk is available in black. To cover an entire wall, dry-erase wallcovering should be applied horizontally (railroaded ) with the seams out of the main writing and viewing areas of the wall. Seams are practically invisible when double-cut. The standard roll length is 100 ft (30.5 m), except for the grid surface, which is 98 ft (30 m), and the magnetic surface, which is 75 ft (2.3 m). INTERACTIVE MARKERBOARD 7.211 TACKBOARDS Tackboards are available in a variety of surface materials and manufactured types. For stability, tackable surfaces are usually laminated to a substrate. Standard sizes, usually to a maximum of 48 in. (1,220 mm) high and 16 ft (5 m) long, are available from most manufacturers. Wood or aluminum trim is available in various profiles. Tackable surfaces include the following: • Natural cork: Self-healing, resilient surface in a soft, light-brown color. For tackboards, 1/4-in. (6-mm) thickness is the most common. • Plastic-impregnated cork: Integrally colored natural cork that has been treated with binders, impregnated with plastic, and surface sprayed with a plastic coating that provides a washable, durable surface. Usually 1/4 in. (6 mm) thick and laminated to a burlap backing. A variety of colors are available. • Vinyl fabric: Type II, medium-duty vinyl fabric. • Fiberboard: Recycled wood fibers are compressed without formaldehyde-containing adhesives into panels with heavyweight jute fabric (burlap) coverings. These acoustically absorptive panels are paintable. INTERIOR SIGNAGE Interior signage is a critical element in the success of interior spaces. Signage is used as a means of wayfinding, where users are provided with a system of navigational cues to guide them through an architectural environment. Interior signage is the most important component of this navigation system, used for information, direction, destination identification, and depiction of regulatory conditions and emergency locations, such as stair exits. INTERACTIVE MARKERBOARDS Interactive markerboards are products on which touch recognition software allows presenters to write with a variety of common instruments, erase with the palm of their hand, and move objects with a fingertip. Interactive whiteboards are undergoing rapid development and becoming widely used by educational institutions and businesses. They are available either alone or with integrated short throw projectors positioned above the board. Control panels may be integrated into the board or remotely located. Adjustable mounts are available that facilitate use at a variety of heights. Interior signs may be visual, tactile, digital, or a combination of multiple information techniques. Local codes and ADA Standards provide information on regulated sign types. CHALKBOARDS AND MARKERBOARDS 7.210 Interior signs may be freestanding, wall mounted, floor mounted, or suspended from overhead ceilings or structures. Signs may be framed or unframed, custom designed, and fabricated or specified from a premanufactured modular sign product line. SIGNAGE PROGRAMS Successful interior sign programs are created based on a recognizable signage hierarchy, with different levels and types of signage determined by the decision points along the user’s wayfinding path. A flow of information, from general to specific, greatly assists the visitor in wayfinding. Source: Walltalkers, Fairlawn, Ohio. DRY-ERASE WALLCOVERING SEAM PLACEMENT 7.212 Source: Walltalkers, Fairlawn, Ohio. Source: Walltalkers, Fairlawn, Ohio. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 151 INTERIOR F INISHES SIGN CATEGORIES Interior signs and graphics may be categorized into six basic types: brand/identity, informational, directional, identification, regulatory, and warning. • Brand/identity signs and graphics, including company logos, brand colors, patterns, and identity graphics, convey proprietary corporate brand messaging. • Informational (operational) signs, including lobby directories and locator maps, provide general location and overall wayfinding information and tell about an environment’s operations. • Directional signs, such as office floor directories and corridor directional signs, provide more specific local wayfinding information for areas or departments. • Identification signs mark a point of arrival or entry (office, stair, or amenity) and may feature changeable inserts if the room occupant or function is temporary. Rooms and spaces having a permanent function, such as restrooms and stairwells, are furnished with permanent graphic information. Local codes and ADA requirements may determine sign types. • Regulatory signs, such as fire egress maps, elevator lobby code signs, and maximum occupancy signs, may be mandated by local codes and regulatory agencies. Many regulation signs are required to address life safety concerns. ADA requirements apply to many regulation signs. • Warning graphics, including policy signs and hazard markings on interior glass walls or alarmed doors messages, may be mandated by local codes and regulatory agencies. Two additional sign categories that may be considered for specific applications are honorific, such as donor recognition signs or installations, and interpretive, where signs and graphics describe the meaning or history of an environment. SIGNAGE SYSTEMS Custom-designed signs require input from a sign designer, require more up-front lead time for design, and may be more expensive to manufacture than modular sign systems, but they allow a program to be tailored to a client’s brand, space, and needs. The alternative is selecting signs from a modular product line. Companies offer premanufactured signage systems that address the needs for moduWALL-MOUNTED CUSTOM SIGNS 7.213 larity, flexibility, and consistency within a family of signs, with quick turnaround. Modular signage systems are available with changeable modular elements for flexibility and often include ADA signs. INTE R I O R CO N ST RU CT I O N 151 INTERNATIONAL ACCESSIBILITY SYMBOLS 7.215 ACCESSIBLE SIGNAGE The 2010 ADA Standards for Accessible Design establish guidelines for accessible signage. All signage required to be accessible must meet these requirements, as well as any applicable local or state accessibility standards. ACCESSIBLE SIGN CATEGORIES Accessible signs must be provided in permanent rooms and spaces. Directional, informational, and overhead signs do not require tactile and Braille lettering, but they must meet 2010 ADA Standards for Accessible Design criteria. • Signs identifying rooms and spaces, whose function will not easily or readily change, must include tactile and Braille text. An office identification sign with a temporary room occupant may include a nonaccessible name plaque in addition to the accessible room identification sign. • Wall-mounted signs that provide direction to or information about functional spaces are not required to include tactile and Braille lettering. However, they must meet requirements for character proportion and height, sign finish, and contrast. • Signs that are projected or suspended overhead must meet requirements for clearance, character proportion and height, sign finish, and contrast. • Building directories, menus, and all other signs that provide temporary information about rooms and spaces, such as the current occupant’s name, are not required to comply with ADA Standards. "• Exit signs at doors at exit passageways, exit discharges, and exit stairways must meet tactile requirements. • Directional exit signs and signs at areas of refuge must comply with requirements for visual characters and features. Source: Society for Environmental Graphic Design, Washington, DC. VOLUME-CONTROLLED TELEPHONE 7.216 ENTRANCES, RESTROOMS, AND BATHING FACILITIES The International Symbol of Accessibility (ISA, or “wheelchair symbol”) must be displayed at accessible facility entrances if all entrances are not accessible. Directions must be provided from inaccessible entrances to accessible ones. Similar guidelines apply to restrooms and bathing facilities. • Exit signs at doors at exit passageways, exit discharges, and exit stairways must meet tactile requirements. • Directional exit signs and signs at areas of refuge must comply with requirements for visual characters and features. PERMANENT ROOM SIGNS ASSEMBLY AREAS The International Symbol of Access for Hearing Loss must be displayed where assistive listening systems are provided, along with a description of the specific listening system. AREAS OF RESCUE ASSISTANCE WALL-MOUNTED UPDATABLE SIGNS 7.214 Areas of rescue assistance must be identified. If an illuminated exit sign is present, an illuminated sign stating “Area of Rescue Assistance,” including the ISA, is required. Instructions must be posted within the area on how to use the area during emergencies. Inaccessible exits must be identified, and signs are required to direct visitors to accessible exits and areas of rescue assistance. FIELD • • • • • Minimum height 5/8 in. (16 mm), uppercase Tactile text, raised, minimum 1/32 in. (0.8 mm) Sans serif or simple serif font Characters must contrast with background Grade 2 Braille PERSONNEL NAME STRIPS • As temporary signs, exempt from the ADA design guidelines TYPICAL PERMANENT ROOM SIGN 7.217 PUBLIC TELEPHONES Text telephones must be identified with the International Telecommunications Device for the Deaf (TDD) symbol. Volumecontrol telephones must be identified by the International Symbol of Access for Hearing Loss. Source: ASI-Modulex, Dallas, Texas. Contributor: Tom Horton, Gensler, San Francisco, California. Source: ASI-Modulex, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 152 152 I N T E R IO R CO NST RU CTION RESTROOM SIGNS Information on the nearest accessible restroom is required only when not all restrooms are accessible. INTERIOR F INISHES HEIGHT OF TACTILE CHARACTERS ABOVE FINISH FLOOR 7.220 SYMBOLS Symbols, or pictograms, are used to identify amenities and services, usually accompanied by the written description. SYMBOLS 7.222 FIELD • Minimum height 6 in. (152 mm) • Pictogram border or background field • Pictogram not required to be raised ROOM DESIGNATION • • • • • Minimum height 5/8 in. (16 mm), uppercase Tactile text, raised, minimum 1/32 in. (0.8 mm) Sans serif or simple serif font Text may not be within background field Grade 2 Braille TYPICAL RESTROOM SIGN 7.218 must be located between 48 and 60 in. (1,220 and 1,525 mm) above the floor or ground. The 2010 ADA Standards for Accessible Design require tactile characters on signs to be located 48 in. (1,220 mm) minimum above the finish floor, measured from the baseline of the lowest tactile character, and 60 in (1,525 mm) maximum above the floor, measured from the baseline of the highest tactile character. The 2010 ADA Standards for Accessible Design require that a tactile sign at a door should be mounted alongside the door on the latch side. For double doors with one active leaf, the sign should be located on the inactive leaf; where both leaves are active, it should be mounted to the right of the right-hand door. Signs may be located on the nearest adjacent wall where there is no wall space available on the latch side of a single door or to the right of a right-hand door. Signs containing tactile characters should be located with a clear floor space of 18 by 18 in. (455 by 455 mm) minimum, centered on the tactile characters, beyond the arc of any door swing between the closed position and the 45° open position. Signs with tactile characters are permitted on the push side of doors with closers and without hold-open devices. Source: ASI-Modulex, Dallas, Texas. Many interior environments with kitchen or breakroom facilities have recycling bins or cabinets that require labeling. Using pictograms is a way to provide quick recognition of the appropriate recycling container, as silkscreen or vinyl applications. RECYCLING SYMBOLS 7.223 SIGNAGE MOUNTING HEIGHTS 7.221 OVERHEAD SIGNS • Minimum height 3 in. (76 mm), uppercase • Minimum 80 in. (2,032 mm) from underside of suspended or projecting sign to finished floor TYPICAL OVERHEAD SIGN 7.219 SIGNAGE MATERIALS Source: ASI-Modulex, Dallas, Texas. EMERGENCY EGRESS SIGNS Some local jurisdictions require additional signage to respond to the need for improved egress and area identification in the event of an emergency for buildings over three stories high. The sign types listed here are in addition to the code-required signage for these spaces: Source: ASI-Modulex, Dallas, Texas. TACTILE MESSAGES AND MOUNTING HEIGHTS Tactile messages with raised characters and Braille are required on signs provided as permanent designations of rooms and spaces. ANSI/ICCA117.1 allows either combined tactile/visual characters or separate tactile characters with redundant visual characters. Room numbers, room names, exit stairs, and restrooms are examples of spaces with “permanent” designations. Tactile characters Contributors: Tom Horton, Gensler, San Francisco, California. Mark J. Mazz, AIA, Hyattsville, Maryland • • • • • • Exit route toward stairwell entries Stairwell identification Additional area of rescue assistance identification Elevator car identification Evacuation floor plans with emergency equipment locations Work space and office locator maps DETECTABLE WARNINGS Detectable warnings are required at passenger transit platforms whose edges border a drop-off where no screen or guard is provided and on most curb ramps. The detectable warning should be a strip of truncated domes, 24 in. (610 mm) wide, which contrasts with the adjacent walking surface. Signs are available in numerous materials and finishes. Typical materials include: • Photopolymer (for raised, tactile messages on ADA signs), in varying colors • Acrylic, natural and painted • Metal (aluminum, steel, stainless steel, brass, bronze, copper, etc.), in varying finishes • Glass • Wood, natural and painted • Solid surface materials and polymers Operational signs, such as main lobby directories, are available as illuminated and nonilluminated units, typically furnished with glass or acrylic covers and metal frames or housings. SIGNAGE GRAPHICS AND TEXT Signage graphics and text vary based on the sign type, design, and ADA requirements. Review overall sign types required for a project to assess 2010 ADA Standards for Accessible Design or other regulations, which may affect signage graphics or text aesthetics. Sign messages and graphics may be applied directly to interior archi- 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 153 INTERIOR F INISHES tectural surfaces, or contained on sign plaques or assemblies. Typical applications include: • • • • • • Silk-screened graphics Vinyl graphics Digital imprinting on vinyl Cast, etched, or paint-infilled metal Sandblasted, silk-screened, or vinyl-applied glass Fused materials ELECTRONIC INFORMATION SYSTEMS Changeable signs typically require manual replacement of an insert or other hard-copy text or graphic. Computer interfaces for signage address the need for flexibility and changing information, mapping, routing, and messages. They may be used at locations where 2010 ADA Standards for Accessible Design requirements for static signs are not required, such as in main lobby directories or at information booths at the entrance to conference rooms. Some sign systems have video technology capabilities integrated into the sign system. ELECTRONIC KIOSK 7.224 entirely from recycled materials, and innovative graphics application techniques provide more design opportunities for banner display constructions. STANDARD BANNER FABRICS Common fabrics used for banners include vinyl laminates, vinylcoated mesh, vinyl-coated polyester, acrylic-coated polyester, nylon, solution-dyed acrylic, solution-dyed modacrylic, and spunbonded polyolefin. Metal and plastic pieces have been made into or sewn onto banners for visual variety. Decorative elements, lighting, and many other materials can be incorporated into banners. INTE R I O R CO N ST RU CT I O N 153 Chair rails were traditionally used to protect walls from chairs as they were moved out from dining tables. They are used in restaurants to keep table edges and chair backs from damaging walls. Residential chair rails are typically 32 in. (813 mm) above the finish floor, but can be placed higher or lower depending on furniture dimensions. Chair rails are available in wood and synthetic materials in a wide variety of styles. They provide a visual separation between the upper and lower wall, and can be used where two wall finishes meet. BUMPER GUARD 7.226 WALL AND DOOR PROTECTION MATERIALS Wall and door protection prevents damage from people kicking or leaning on surfaces, from rolling carts and equipment, and from maintenance equipment. Materials used to protect walls and doors include: • PVC plastic: This durable plastic is used for corner guards, crash rails, rub rails, etc. • Polycarbonate plastic sheet: Polycarbonate is used for wainscot. • Aluminum extrusions: Aluminum is used for corner guards, crash rails, rub rails, etc. • Stainless steel: This durable metal is used for wainscot and for corner guards, crash rails, rub rails, etc. • Solid wood: Used for wainscot paneling or for corner guards, crash rails, rub rails, etc., solid wood shows abuse but can be refinished. • Particleboard: This is used for wainscot (typically in dock areas), but may show abuse. CHAIR RAILS 7.227 WALL GUARDS AND CHAIR RAILS Wall guards, panels, and trim are typically attached to a finished wall surface with adhesive or screws. For all wall and corner guard installations, it is important to provide backup blocking behind areas where fasteners are attached; this is particularly necessary for handrail-type guards. Types include: DIRECTORY AND INFORMATION KIOSKS A common information sign feature used as an introduction to larger facilities with complex wayfinding challenges, multiple tenants, or significant public access is a directory kiosk. These kiosks are generally freestanding, but may also be wall mounted where there are space constraints. Kiosks may incorporate static “You Are Here” orientation maps (internally illuminated or nonilluminated), tenant directories with modular message strips, video flat screens, or electronic dynamic sign displays. INTERIOR SIGNAGE INSTALLATION Interior signage installation varies with the application, substrate or mounting surface, sign weight, and other factors, which should be reviewed with the signage manufacturer and installer. Signage requiring mechanical fastenings may require additional blocking or support to the wall surface to ensure stability. Consider sign mounting with mechanical fasteners, if they can be integrated into the look of the sign, to avoid the use of high-VOC glues and adhesives. Wall-mounting options for small signs include: • • • • • Mechanical fastening Vinyl tape Silicone adhesive Velcro Magnetic tape BANNERS TYPES Traditionally, banners have been pole mounted, wall mounted, or wall hung, similar to the way flags are displayed. Today, however, the availability of a wide variety of banner fabrics, some made Contributor: Tom Horton, Gensler, San Francisco, California. • Stainless steel wall guard may be manufactured as a preassembled length from field dimensions. • Aluminum wall guard is made of 1/4 in. (6 mm) thick anodized aluminum. • Thin wall guard is used for light to medium duty with minimal space requirements A rigid vinyl cover is mounted on a continuous aluminum retainer. Thin wall guard is available with tapered ends to avoid contact with hospital beds, carts, and dollies. CRASH RAILS 7.225 HANDRAILS Impact-resistant plastic handrails are available with germ-fighting plastic surfaces and aluminum alloy interiors. They are designed to be easy to install and are used in healthcare facilities. Solid wood handrails are available in oak, beach, birch, maple, and other woods. They can be made with curves, and are available with stainless steel intermediate supports. Handrails made with heavyweight PVC veneers bonded to mediumdensity fiberboard (MDF) are sturdy, noninstitutional in appearance, and easy to maintain. HANDRAILS 7.228 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 154 I N T E R IO R CO NST RU CTION DOOR PROTECTION SYSTEMS Door protection plates are fabricated from architectural aluminum, brass, or stainless steel, or from plastic laminate, 1/8 in. (3 mm) thick clear acrylic plastic, or black or brown high-impact polyethylene. Page 154 INTERIOR F INISHES INCREASED PRIVACY COMPARTMENTS 7.231 PHENOLIC CORE UNITS • Kick plate: This rectangular surface protects the bottom of the push side of doors subject to scuffing from foot traffic. Kick plates are recommended for all doors subject to normal use and especially for doors using a closer. • Armor plate: This product protects the lower half of doors from abuse by hard carts, trucks, and rough usage. An armor plate is usually applied to the push side of single doors and both sides of double-acting doors. • Stretcher plate: This plate protects doors at specific areas where consistent contact is made by service carts or other equipment. It is usually applied to the push side of doors. • Mop plate: A mop plate protects the bottom of the pull side of doors subject to cleaning and mopping procedures. Phenolic core panel materials are fabricated by fusing multiple layers of resin-impregnated core sheets or cellulose fibers with thermosetting resins to melamine facing sheets. Panels resist damage from moisture and impacts. The melamine surfaces resist damage from chemicals, urine, stains, and abrasion; however, they can be scratched with hard objects to expose the core. The core is exposed on panel edges and is either black or brown. SOLID POLYMER UNITS DOOR KICK PLATE DIMENSIONS 7.229 PANEL MATERIALS TYPE Kick plate HEIGHT WIDTH 8 to 24 (203 to 610 mm) 22 to 48 (559 to 1,219 mm) Armor plate 26 to 48 (660 to 1,219 mm) 22 to 48 (559 to 1,219 mm) Stretcher plate 6 to 8 (152 to 203 mm) 22 to 48 (559 to 1,219 mm) Mop plate 4 to 6 (102 to 152 mm) 22 to 48 (559 to 1,219 mm) DOOR KICK PLATES 7.230 resistant but can be scratched with sharp instruments. Plastic laminate units are not suitable for areas subject to moisture or high humidity because prolonged exposure can cause delamination of the facing from the core. Toilet compartments are often categorized by finish or construction. Common finish categories include the following: • Metal, including baked enamel and stainless steel • Polymers, including plastic laminate, phenolic core, melaminefaced particleboard cores, FRPs with particleboard cores, solidsurfacing materials, and solid-surfacing veneers • Stone, including marble, granite, and some limestones Factory-finished hardwood units (which are generally used for highcost installations) are also available. Materials may be combined; for instance, compartments may have plastic laminate doors and panels with stainless steel pilasters. Baked-enamel and plastic laminate panels are also available with stainless steel edge strips. METAL TOILET PARTITIONS Metal units include stainless steel units with sound-deadening honeycomb cores made from resin-impregnated kraft paper, and baked-enamel units. Where grab bars are attached, metal compartment manufacturers provide wood or particleboard reinforcement or through-bolting kits. Solid polymer units are fabricated from high-density polyethylene (HDPE) or polypropylene (PP) panels, and resist damage from moisture and impacts. Surfaces resist staining, as well as marking with pens and pencils. PP panels are harder and more scratch and dent resistant than HDPE panels, and are virtually graffiti-proof. Colors and patterns are homogeneous through the thicknesses of solid polymer panels, so scratches can sometimes be burnished out. STONE TOILET PARTITIONS The most common varieties of stone used for stone toilet compartments are marble and granite. Limestone that is compact and dense and capable of taking a polish is suitable for use in toilet compartments and can be marketed as either limestone or limestone marble. Polished finishes are most commonly specified for marble and granite toilet compartments. Honed finishes are less frequently specified because they more readily absorb stains. MOUNTING STYLES Mounting styles include overhead-braced, floor-anchored, ceilinghung, and floor-and-ceiling-anchored styles. Baked-enamel, stainless steel, plastic laminate, and phenolic core units are generally available in all four mounting styles. Solid polymer units are generally available in overhead-braced and floor-and-ceiling-anchored styles. STANDARD PARTITION MOUNTING HEIGHTS 7.232 STAINLESS STEEL UNITS Stainless steel units have excellent long-term durability. They are corrosion resistant, and stains may be removed with commercial stainless steel cleaners. They resist denting and marring, but can be scratched with a sharp instrument. Scratches can sometimes be removed by buffing. PUSH AND PULL PLATES Push plates are available in brass, bronze, plastic, stainless steel, and aluminum. A variety of designs and sizes are made; standard sizes include: • • • • 3-1/2 by 15 in. (89 by 381 mm) 4 by 6 in. (102 by 152 mm) 6 by 16 in. (152 by 406 mm) 8 by 16 in. (203 by 406 mm) TOILET COMPARTMENTS SELECTION CRITERIA When selecting toilet enclosures, screen types, and mounting styles, consider requirements for maintenance, vandal and moisture resistance, supporting construction, and methods for repairing damaged units. Taller-than-average doors and panels are used to help ensure privacy. Systems that incorporate a lap joint at doors and pilasters to eliminate vertical sightlines into compartments are available from a number of solid polymer and phenolic core unit manufacturers. Some metal units can be modified to include stops and fillers to eliminate vertical sightlines at doors. BAKED-ENAMEL UNITS The term baked enamel is used to describe various pigmented, organic coatings. The baking process is used to accelerate the solvent evaporation or, for thermosetting coatings, to elevate temperatures to the point required to convert the film to a polymerized form. Manufacturers usually describe finishes as electrostatically applied enamel, high solids, or powder coatings. Steel units with baked-enamel finishes are the most economical and widely available type of toilet compartment, but they have the least durable finishes. They are not suitable for areas subject to moisture; although finishes resist corrosion, the panels are susceptible to rust. Finishes are generally adversely affected by chemicals and acids but are resistant to stains made by items such as felt-tip markers or lipstick as long as the staining agent is promptly removed. POLYMER TOILET PARTITIONS Plastic laminate, phenolic core, and fiberglass-reinforced panels are the more affordable choices for polymer toilet partitions. Solidsurfacing materials and solid-surfacing veneers are also available. PLASTIC LAMINATE UNITS Plastic laminate units with particleboard cores are resistant to normal wear, acids, and alkalis, as well as to stains made by felt-tip markers, lipstick, and similar materials. Surfaces are abrasion Contributor: Suzanne Simpson, Gensler, Dallas, Texas. • Overhead-braced compartments are the most economical in initial cost; they provide a sturdy installation without the substantial structural connections required for other mounting styles. The majority of installations use this mounting style. • Floor-anchored compartments are the least stable of the mounting styles when resisting lateral loads; hence, they require substantial connections to a structural concrete slab to provide a rigid installation. They are generally not suitable for schools or other installations subject to high abuse. • Ceiling-hung compartments when used in combination with wallhung fixtures, produce unobstructed floor areas that make maintenance easier. Generally, the maximum ceiling height recommended for this style is 96 in. (2,438 mm). Separate overhead steel support framing is required. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 155 INTERIOR F INISHES • Floor-and-ceiling-anchored compartments are exceptionally strong and are used where vandal resistance is required. Most manufacturers limit pilaster heights to 108 in. (2,743 mm). Pilasters are attached to the floor using the same devices as overhead-braced or floor-anchored styles, depending on the manufacturer. Separate overhead support framing is required. STANDARD COMPARTMENT LAYOUTS 7.233 Contributors: American Sanitary Partition Corporation, Ocoee, Florida. MASTERSPEC®, published by ARCOM, Salt Lake City, Utah. INTE R I O R CO N ST RU CT I O N 155 OVERHEAD-BRACED COMPARTMENTS 7.234 CEILING-HUNG COMPARTMENTS 7.236 FLOOR-ANCHORED COMPARTMENTS 7.235 FLOOR-AND-CEILING-ANCHORED COMPARTMENTS 7.237 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 156 I N T E R IO R CO NST RU CTION Page 156 INTERIOR F INISHES other end. For long bays with a single bench, make 3-ft (914-mm) breaks at 15-ft (4.6-m) intervals. LOCKER ROOMS DESIGN The most widely used arrangement of lockers is the bay system, with a minimum 4 ft (1,219 mm) circulation aisle at each end of the bays. Ordinarily, the maximum number of lockers in a bay is 16. Locate dry (shoe) traffic at one end of the bays and wet (barefoot) traffic at the GYMNASIUM AND POOL LOCKER ROOM 7.240 Benches should be, minimally, 8 in. (203 mm) wide and 16 in. (406 mm) high. Traffic breaks of 3 ft (914 mm) minimum width should occur at maximum intervals of 12 ft (3.7 m). Main traffic aisles should be wider. Avoid lockers that meet at a 90° corner. RECOMMENDED MOUNTING HEIGHTS 7.238 LOCKER ROOM 7.239 LOCKER TYPES Storage lockers come in many sizes and configurations. Dressing lockers are full height (single tier). The number of dressing lockers should be equal to the peak period load plus 10 to 15% to allow for expansion. Locker types include: • Single-, double-, triple-, and four-tier stacked heights • 3, 4, 5, and 6 high boxes • Duplex (two side by side), two-person (side by side with two top horizontal shelves), and double-door (single lock) • Ski and golf equipment styles • Cubbies (open storage) for child care LOCKER ROOM DIMENSIONS FUNCTION A B C Recreation 2-2 (660 mm) 1-8 (508 mm) 3-6 (1,066 mm) School 2-6 (762 mm) 2-6 (762 mm) 4-0 (1,219 mm) 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 157 INTERIOR F INISHES ACCESSIBILITY LOCKER TYPES 7.241 The 2010 ADA Standards for Accessible Design require that where lockers are provided in clusters, at least 5%, but no less than one, should be accessible. Storage elements and operable parts are required to comply with at least one of the required reach ranges. Lockers are available with adjustable shelf locations to meet these requirements. ADA-compliant benches are also available. INTE R I O R CO N ST RU CT I O N 157 LOCKER SECTION 7.244 COMMON LOCKER SIZES 7.242 LOCKER TYPE Standard lockers WIDTHS 9 (229 mm) DEPTHS HEIGHTS 12 (305 mm) 60 (1,524 mm) 15 (381 mm) 72 (1,828 mm) SEISMIC CONSIDERATIONS 18 (457 mm) 12 (305 mm) 12 (305 mm) 60 (1,524 mm) 15 (381 mm) 72 (1,828 mm) 18 (457 mm) 21 (533 mm) 15 (381 mm) 12 (305 mm) 60 (1,524 mm) 15 (381 mm) 72 (1,828 mm) Lockers and racks can slide and/or overturn during seismic activity, injuring building occupants or blocking exits. The hazard increases with the occupancy density and the height of the units. The center of gravity of a locker rises with the height of the unit, thus increasing the possibility of overturning in an earthquake. Fixtures should be bolted onto heavy-gauge studs above their center of gravity. If lockers or cabinets cannot be anchored, locate them away from exits, hallways, and doors. 18 (457 mm) 21 (533 mm) 18 (457 mm) 24 (610 mm) 18 (457 mm) 60 (1,524 mm) 21 (533 mm) 72 (1,828 mm) 21 (533 mm) 60 (1,524 mm) 72 (1,828 mm) Standard school storage lockers 9 (229 mm) 12 (305 mm) 12 (305 mm) 24 (610 mm) 12 (305 mm) 12 (305 mm) 12 (305 mm) Standard school dressing lockers 12 (305 mm) 12 (305 mm) 60 (1,524 mm) Cubbies 12, 15, 18 (305, 381, 457 mm) 15 (381 mm) 48 (1,219 mm) 24 (610 mm) 72 (1,828 mm) COMMON LOCKER SIZES 7.243 Contributors: BFS Architectural Consulting and Interior Design, YMCA of the USA, Chicago, Illinois. Frederick C. Krenson, AIA, Rosser Fabrap International, Atlanta, Georgia. LOCKERS—SEISMIC ANCHORING 7.245 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 158 I N T E R IO R CO NST RU CTION FIREPLACES AND STOVES The fireplace and chimney are usually large elements in residences, but their scale can be adapted to any architectural style. Fireplaces and heating stoves are also occasionally found in nonresidential buildings, such as restaurants. Although the purpose of the residential fireplace has changed over the years from heating to decoration, increasing public interest in renewable forms of energy has instigated a new demand for fireplaces for heating homes. Fireplace design and construction are governed by building and mechanical codes. The main function of the fireplace and chimney is to sustain combustion and carry smoke away safely. Their design is based on empirical data proven with years of safe performance. One of the most important design decisions is the location of the fireplace. To prevent heat loss to the exterior, it is best to locate a fireplace at the center of the house. A fireplace should not be located opposite an outside door or near an open stairway leading to an upper floor, a forced-air furnace, or a return air register. Three distinct types of fireplaces are currently used in residential applications. • Single-face fireplace styles, the most popular, include the conventional fireplace, the Rumford fireplace, the Rosin fireplace, and air-circulating fireplaces. • Multiface fireplaces are also popular; they include the seethrough fireplace, the corner fireplace, and the freestanding fireplace. • The masonry heater (or masonry stove) is a specialized type of fireplace, and is the most efficient of these types. Page 158 INTERIOR F INISHES MASONRY FIREPLACES Single-Face Construction Most masonry fireplaces are built on-site using common masonry materials (brick, mortar, etc.) and custom metal supports (lintels, dampers, etc.). The most common format for open masonry fireplaces has been with a firebox that is enclosed in masonry with only one side (face) open to the room. Typical single-face construction allows for an excellent combustion environment, increasing combustion temperatures and reflecting a significant amount of heat into the room. However, open single-face fireplaces must also exhaust the fire, smoke, and heat through a throat and smoke chamber into a flue, thus powering the flue, in order to maintain a constant flow to the exterior atmosphere. Following the route of the chimney backward, it geometrically projects into the room at the lintel; this projection is called the chimney breast. Two methods of design and construction clearly illustrate the range and features of functional fireplaces, both traditional and modern in design. This discussion details two contrasting solutions: • Traditional fireplaces, essentially constructed using all-masonry components, with clay-lined chimneys sited on exterior walls. • Modern fireplaces utilizing components that are not as traditional; for example, metal chimneys located within the building envelope. Typically, modern fireplaces still maintain firebrick fireboxes. TRADITIONAL CONSTRUCTION PERFORMANCE CRITERIA Site-built fireplaces are typically designed to operate as open systems, without closed doors but including screens, and to be capable of either burning wood or housing certain gas appliances. This is the classical form for the fireplace, used for direct radiant heat and ambience. Properly designed, a fireplace will perform as intended, not spill smoke into the room, and provide supplemental heat during the peak of the fire. FIREPLACE DESIGN Masonry fireplaces must be set on footings and foundations built on firm soils. Typically, all-masonry fireplaces are constructed with brick, stone, or block from footing to termination, and lined with firebrick in the firebox and clay tiles in the chimney above the smoke chamber. With more refined internal geometry, modern fireplaces are typically built at various levels of a building and can be set on engineered slabs supported by steel frames. In this era of pollution control and energy awareness, the modern fireplace incorporates advanced insulations and stainless steel to house sensitive exhaust, confining fuel loads to smaller hearths that complete combustion. Traditional fireplace construction supports a damper at a narrowing of the firebox throat, at least 8 in. (203 mm) above the opening in the facade. A tapered smoke chamber transforms the rectilinear flow of air and smoke from the fireplace into a square or round flue. MODERN CONSTRUCTION Modern fireplace construction utilizes advanced materials to optimize performance and integrate with building programs. Air ducts and insulation protect steel-reinforced slabs, and continuously sloped rear walls reflect heat both into fuel loads for better combustion and toward the room for greater efficiencies. Insulated smoke chambers, lined with heavy steel forms, clay tiles, or firebrick, continue the cause of better draft—key to vigorous and clean combustion and safe for stick frame construction. Typically, there are concrete masonry unit (CMU) casings, isolated from the hot internal chambers, which form permanent structural housings; these are reinforced in seismic areas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 159 INTERIOR F INISHES TRADITIONAL MASONRY FIREPLACE—SECTION 7.246 INTE R I O R CO N ST RU CT I O N 159 TRADITIONAL MASONRY FIREPLACE—ELEVATION 7.248 TRADITIONAL MASONRY FIREPLACE—PLAN 7.249 TRADITIONAL MASONRY FIREPLACE DIMENSIONS 7.247 A B C D E G H 24 (610 mm) 24 (610 mm) 16 (406 mm) 8 (203 mm) 3-1/2 32 (813 (89 mm) mm) F 18 (457 mm) 29-1/2 13-1/2 10 (749 (243 (254 mm) mm) mm) I J 30 (762 mm) 28 (711 mm) 16 (406 mm) 8 (203 mm) 3-1/2 36 (914 (89 mm) mm) 24 (610 mm) 29-1/2 13-1/2 10 (749 (243 (254 mm) mm) mm) 36 (914 mm) 30 (762 mm) 16 (406 mm) 8 (203 mm) 4 (102 mm) 38 (965 mm) 28 (711 mm) 29-1/2 13-1/2 12 (749 (243 (305 mm) mm) mm) 32 42 (1,067 (813 mm) mm) 18 (457 mm) 8 (203 mm) 4 (102 mm) 30 40 (1,016 (762 mm) mm) 31-1/2 15-1/2 12 (800 (394 (305 mm) mm) mm) 36 48 (1,219 (914 mm) mm) 20 (508 mm) 8 (203 mm) 36 4-1/2 42 (115 (1,067 (914 mm) mm) mm) 33-1/2 17-1/2 14 (851 (445 (356 mm) mm) mm) 38 54 (1,372 (965 mm) mm) 22 (559 mm) 8 (203 mm) 35-1/2 19-1/2 16 42 4-1/2 46 (115 (1,168 (1,067 (902 (495 (406 mm) mm) mm) mm) mm) mm) 24 40 60 (1,524 (1,016 (610 mm) mm) mm) 8 (203 mm) 5 (127 mm) 48 48 37-1/2 21-1/2 18 (1,219 (1,219 (953 (546 (457 mm) mm) mm) mm mm) NOTES 7.247 a. The flue liner outside dimensions (O.D.) are equal to the inside dimensions (I.D.) of the flue liner (J) plus at least 2 in. (51 mm). b. Consult manufacturers for flue liner sizing that matches or is the next size larger on round and square liners; for example, 15 in. (381 mm) round liner (I.D.) for 14-in. (356 mm) sizing, or 16 in. (406 mm) square liner (O.D.) with 1 in. (25 mm) wall thickness. c. Minimize use of rectangular liners to optimize fireplace flue performance. LEGEND A B C D Opening width Opening height Firebox depth, which assumes a minimum masonry facade thickness of 4 in. (102 mm) to achieve a minimum coderequired hearth depth of 20 in. (508 mm) Throat E F G H I J Recommended minimum net horizontal opening with damper blade fully open, which varies by manufacturer Firebox height Smoke chamber height Total interior dimension Smoke chamber opening Flue inside dimension 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 160 160 I N T E R IO R CO NST RU CTION INTERIOR F INISHES MODERN MASONRY FIREPLACE—SECTION 7.250 MODERN MASONRY FIREPLACE—ELEVATION 7.252 MODERN MASONRY FIREPLACE DIMENSIONS 7.251 A B C D H I J K 36 (914 mm) 30 (762 mm) 20 (508 mm) 11-1/2 5 (292 (127 mm) mm) E 41-1/2 20 (1,041 (508 mm) mm) F G 31 (787 mm) 13 (330 mm) 12 (305 mm) 17 (432 mm) 33-1/2 20 42 (1,067 (851 (508 mm) mm) mm) 11-1/2 6 (292 (152 mm) mm) 24 45 (1,143 (610 mm) mm) 31 (787 mm) 13 (330 mm) 12 (305 mm) 17 (432 mm) 21 40 48 (1,219 (1,016 (533 mm) mm) mm) 13-1/2 6-1/2 53-1/2 24 (243 (165 (1,359 (610 mm) mm) mm) mm) 34 (864 mm) 15 (381 mm) 14 (356 mm) 18 (457 mm) 54 22 43 (1,372 (1,092 (559 mm) mm) mm) 13-1/2 6-1/2 56-1/2 28 (292 (165 (1,435 (711 mm) mm) mm) mm) 36 (914 mm) 17 (432 mm) 16 (406 mm) 19 (483 mm) 24 47 60 (1,524 (1,194 (610 mm) mm) mm) 13-1/2 7 (292 (178 mm) mm) 60-1/2 32 (1,537 (813 mm) mm) 38 (965 mm) 19 (483 mm) 18 (457 mm) 20 (508 mm) 26 58 72 (1,829 (1,453 (660 mm) mm) mm) 16 (406 mm) 7 (178 mm) 23 41 40 64 (1,625 (1,016 (1,041 (584 mm) mm) mm) mm) 22 (559 mm) 21 (533 mm) 78 29 65 (1,981 (1,651 (737 mm) mm) mm) 18-1/2 8 (470 (203 mm) mm) 25 44 83-1/2 48 (2,121 (1,219 (1,118 (635 mm) mm) mm) mm) 24 (610 mm) 23 (584 mm) 31 72 96 (2,438 (1,829 (787 mm) mm) mm) 21 (533 mm) 25 46 60 9-1/2 93 (242 (2,362 (1,524 (1,168 (635 mm) mm) mm) mm) mm) 24 (610 mm) 24 (610 mm) MODERN MASONRY FIREPLACE—PLAN 7.253 LEGEND A B C D E F G Opening width Opening height Firebox depth Throat: Modern construction utilizes taller than codeminimum throats of 8 in. (203 mm), incorporating firebrick above the chimney breast until the throat is reached. Minimum opening Firebox height Smoke chamber height NOTES 7.251 a. Metal chimneys must be listed to UL 103HT and be tested for use with masonry fireplaces. b. Exterior dimensions are typically 2 or 4 in. (51 or 102 mm) greater than interior dimensions, and typically require 2-in. (51-mm) clearances to combustibles. H I J K Total interior dimension: Most codes require minimum firebox and smoke chamber masonry thicknesses of 8 in. (203 mm) when at least 2 in. (51 mm) of ASTM firebrick is used. Smoke chamber opening Flue inside dimension Interior face of chimney to centerline of flue 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 161 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 161 INTERIOR SITING Without exception, it is better to place both fireplace and flue within the conditioned interior of a building, where fires and exhausts benefit from warmer conditions and more vigorous flows from taller chimneys. Ideally, this is the modern setting that also incorporates insulated chambers for even better and more efficient conditions. CRITICAL CODE-REQUIRED CLEARANCES 7.254 MULTIFACED CONSTRUCTION Designers are given wide leeway by current codes to create visual options for fire viewing from different rooms or from a range of points in a single room. However, more openings and/or open faces create challenges for fireplace operations. Unless fuel loads increase with opening sizes, the same heat is powering flues that must maintain airflows/pressures over larger areas. Dual-face, or see-through, fireplaces must be carefully constructed and have taller chimneys to create adequate draft for their additional opening conditions. DUAL-FACED, TWIN-FLUE FIREPLACE 7.256 As fireboxes increase in size, so must the throats and smoke chambers. However, if the fuel-loading areas and chimney height do not increase proportionally as well, then the building blocks for good performance will be absent. Larger fireboxes also require greater care in sizing and design. DUAL-FACED, SINGLE-FLUE FIREPLACE 7.255 STRUCTURAL OBSTACLES Firebox flues should prevail in the competition for building space, but sometimes there are significant structural obstacles that require adaptation by the fireplace. That said, smoke chambers must have balanced and symmetrically placed flue connections, and chimneys cannot be offset by greater than 30° off vertical, and only with a maximum of two offsetting runs. Contributor: Walter Moberg, Moberg Fireplaces, Inc., Portland, Oregon. Brian E. Trimble, PE, Brick Institute Association, Reston, Virginia. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 162 I N T E R IO R CO NST RU CTION Page 162 INTERIOR F INISHES PROJECTED FIREPLACES OPEN SUSPENDED DESIGN Some design programs seek even greater fire-viewing potential, with openings on three sides, or faces. Traditionally, peninsula designs with steel columns have provided a variety of multisided geometries. For the ultimate in fire viewing, suspended hoods sometimes found in restaurants offer aerodynamic exhausts over custom masonry bases. Typically, these aerodynamic hoods are engineered with exhaust fans (as in kitchens). Alternatively, there are UL-listed fireplaces with fireboxes and hearths that are suspended completely in the air, and some that even rotate for alternate viewing positions. PENINSULA FIREPLACE WITH STEEL COLUMNS 7.257 OPEN AND SUSPENDED FIREPLACE 7.259 WALL FINISH REQUIREMENTS CODE REQUIREMENTS The International Building Code (IBC) limits the use of interior finish materials based on their flammability, the occupancy group, and the areas of the building in which they are used. Materials and finishes are classified according to their flame spread and smoke developed characteristics when tested in accordance with ASTM E 84, Test Method for Surface Burning Characteristics of Building Materials (Steiner Tunnel Test). Interior finish materials refer to the exposed surfaces of walls and ceilings, including partitions, wainscoting, paneling, and other finishes applied structurally or for decoration, acoustical correction, surface insulation, or similar purposes. Trim such as baseboards, window and door casings, or similar materials used in fixed applications are not included. Trim cannot exceed 10% of the area in which it is located. Interior finish requirements also do not apply to finishes less than 0.036 in. (0.9 mm) thick applied directly to the surface of walls or ceilings or to the exposed portions of structural members complying with Type IV construction requirements. DEFINITIONS • Noncombustible: A material that meets the requirements of ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750°C. This means that the material MODERN FIREPLACE PROJECTED FROM REINFORCED WALL 7.258 will not ignite or burn when subjected to fire. Noncombustible also includes composite materials, such as gypsum wallboard, that are composed of a surfacing not more than 0.125 in. (3 mm) thick that has a flame spread index not greater than 50, as long as the structural base is noncombustible. • Flame resistant: A material that restricts the spread of flame in accordance with NFPA 701, Standard Methods of Fire Tests for Flame Propagation of Textiles and Films. This test is commonly referred to as the Vertical Ignition Test. • Trim: Picture moldings, chair rails, baseboards, handrails, door and window frames, and similar decorative or protective materials used in fixed applications. • Combustible: A material that will ignite and burn, either as a flame or glow, and that undergoes this process in air at pressures and temperatures that might occur during a fire in a building. CLASSIFICATION OF FINISHES 7.260 CLASS FLAME SPREAD SMOKE DEVELOPED A 0 to 25 0 to 450 B 26 to 75 0 to 450 C 76 to 200 0 to 450 WALL FINISH APPLICATIONS As vertical surfaces, walls generally receive less impact than floors. However, certain occupancies are liable to damage from impact or abuse. Others have special sanitation and maintenance requirements. PUBLIC RESTROOMS, SHOWER ROOMS, AND LOCKER ROOMS Walls in public toilet rooms, locker rooms, and shower rooms should be of materials resistant to moisture and should have surfaces that are easily cleaned. All exterior corners in locker rooms should be rounded. Walls within 2 ft (610 mm) of urinals and water closets must have a smooth, hard, nonabsorbent surface, to a height of 4 ft (1,219 mm) above the floor. The material used cannot be a type that is adversely affected by moisture. The exceptions include dwelling units, guest rooms, and toilet rooms that are not accessible to the public and do not contain more than one water closet. Shower compartments must have floor and wall finishes that are smooth and nonabsorbent and that are not affected by moisture. Wall finishes must extend to at least 70 in. (1,778 mm) above the drain inlet. Contributors: Walter Moberg, Moberg Fireplaces, Inc., Portland, Oregon. David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 163 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 163 that have been repaired or bricked-up openings. Paint for application to brick masonry walls should be durable, easy to apply, and have good adhesive characteristics. The primary concern should be the characteristics of the surface conditions of the wall. Proper surface preparation is as important as paint selection. Previously painted brick surfaces often require the greatest effort. Exposed, unpainted brick can be appreciated for the building history revealed by its idiosyncracies. Paint can be removed from existing walls if the bricks were in good condition prior to being painted. REQUIRED NONABSORBENT SURFACE 7.261 PLASTER Conventional plaster provides superior wear resistance compared to taped gypsum board assemblies. Though it is preferred to attain a uniform, monolithic surface, plaster finishes are more labor intensive than taped gypsum board assemblies, require greater skill, and can take as long as two days to cure. For these reasons, plaster finishes are most commonly used in restoration to match existing conditions and in high-end installations. INSTALLATION Plaster is applied in a series of coats of progressive refinement. Two-coat plaster is applied as a base coat followed by a finish coat. Three-coat plaster is applied first as a scratch coat followed by a brown coat and, finally, a finish coat. INTEGRAL WALL FINISHES INTERIOR BRICK WALLS BRICK Brick interior walls may be either load bearing or nonstructural. Bricks are laid in bonds to increase stability and strength. Interior walls faced with brick often have another material behind. Although standard building brick is widely used, there are many colors, textures, and sizes of brick available. The level of refinement produced by uniform brick assembled with accuracy contrasts with bricks made to look older, rougher, and even as though they had been burnt in a fire. Antique salvage bricks are used for a historic or rustic appearance. Walls can intentionally be built with irregularities and curves that are more organic in form than a flat, rectilinear brick wall. Facing brick is used where appearance is important; it is made in special colors and textures for surfacing walls. Ceramic glazed brick is used as facing brick, and is installed in the same manner as facing brick. Thin brick veneer units are fired clay units with normal face dimensions but a reduced thickness. They are used in adhered veneer applications. The size of a brick establishes the scale of the wall. Because fewer large units than smaller units are required to build a wall of a given size, labor costs are generally less for larger bricks. Brick color is determined by raw materials and firing temperatures. Colors range from reds and burgundies to whites and buffs, with manufacturers producing more than 100 colors. Wall ties should be placed at least every 24 in. (610 mm) vertically and 36 in. (914 mm) horizontally, or every 4-1/2 sq ft (0.42 sq m) in a staggered pattern. Expansion joints should be located on each side of a corner at 4 to 10 ft (1.2 to 3 m) from the corner. However, on straight walls, the expansion joints need only be spaced at 3/4 in. (19 mm) per 100 ft (30.5 m) of wall. Flexible anchors are used to connect to columns and beams. SPECIFYING BRICK Brick selection is based on aesthetics, physical properties (compressive strength and absorption, both of which affect durability), application (moisture penetration, movement of materials, and structural loads), cost, and availability. In the United States, the nominal dimensions of standard bricks are 4 by 2-2/3 by 8 in. (102 by 68 by 203 mm). The actual bricks are smaller, and the nominal dimensions add an allowance for the mortar joint. Three standard bricks with mortar total 8 in. (203 mm) vertically. When specifying the size of units, dimensions should be listed by thickness, then by height, and, finally, by length. The dimensions given should be specified, not nominal, dimensions. Textures of brick include smooth, wire cut (velour), stippled, bark, or brushed. Mortar can get into the spaces in rough-textured brick and make cleaning more difficult. Both the brick’s texture and the profile and depth of mortar lines enhance the play of light and shadow. THIN BRICK SUSTAINABILITY MORTAR Brick manufacturing uses raw materials efficiently, typically close to their source. Processed clay and shale removed in the forming process prior to firing are returned to the production stream. Culls after firing are ground and used as grog (fired, ground-up clay) with the prepared material to reduce shrinkage, or crushed for use as landscaping materials. Colored mortars are produced through the use of colored aggregates or suitable pigments. White sand, as well as ground granite, marble, or other stone, usually have permanent color and do not weaken the mortar. For white joints, white sand, ground limestone, or ground marble is used with white portland cement and lime. Clay bricks have relatively low embodied energy. The majority of kilns in the United States use gas as a fuel source, though a third of the brick currently produced is fired using solid fuels such as sawdust and coal. Biomass is being introduced as a fuel for brick making. FINISHES AND MAINTENANCE The market for recycled bricks reclaimed from demolition sites continues to grow. The mortar is cleaned off each brick by hand. Recycled bricks are often taken directly from the demolition site to the construction site, without need for warehousing. Contributor: Corky Binggeli, Materials for Interior Environments, John Wiley & Sons, Hoboken, NJ, 2008. Thin fired clay units referred to as thin brick are used as interior or exterior wallcoverings. Thin brick veneer is formed from shale and/or clay and kiln fired. These thin brick units resemble facing brick, but are only 1/2 to 1 in. (13 to 25 mm) thick. Colorless coatings are generally applied to interior walls to facilitate cleaning or provide a gloss; water repellency and breathability are generally not concerns. A film-forming product such as a waterborne acrylic (acrylic emulsion) or urethane can be used to improve gloss and ease of cleaning. Both are durable in applications where there is no exposure to ultraviolet light. Interior brick walls may be painted to increase light reflection or for decorative purposes. Walls are also painted to conceal areas Three-coat plaster applications are required on all metal lath and on edge-supported gypsum lath used in ceilings. Three-coat applications are preferred on gypsum lath assemblies, but two-coat applications are acceptable where gypsum lath is properly supported and on masonry plaster bases such as porous brick, clay tiles, and rough concrete masonry units. Plaster can be constructed as a solid plaster partition stabilized with proprietary ceiling runners and metal base anchors. Solid plaster partitions 2 in. (51 mm) thick are made by applying threecoat plaster to both sides of metal lath on 3/4 in. (19 mm) channel studs, or with metal lath on a 1/2 in. (13 mm) gypsum lath or 1 in. (19 mm) core board. Plaster can also be applied directly to brick, clay tile, or concrete masonry where the surface is rough and porous enough to produce a good bond. A bonding agent is used when plaster is applied directly to dense, nonporous surfaces such as concrete. SOLID PARTITION TERMINALS 7.262 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 164 I N T E R IO R CO NST RU CTION PLASTER OVER SOLID GYPSUM LATH 7.263 Page 164 INTERIOR F INISHES DEFINITIONS • Base coat : A plaster coat applied before finish coat, scratch CORNER BEADS 7.268 coat, and blow coats in three-coat plaster • Brown coat : In three-coat plaster, the second coat; in two-coat plaster, the first coat • Finish coat : The final coat of plaster, which provides the decorative surface • Gypsum : Hydrous calcium sulfate, a natural mineral in crystalline form • Gypsum lath : A sheet having a gypsum core, faced with paper, used as a base for plaster; also perforated for interior use • Hydrated lime: Quicklime mixed with water on the job, to form a lime putty • Plaster: A cementitious material or combination of cementitious materials and aggregate that, when mixed with water, forms a plastic mass that sets and hardens when applied to a surface • Portland cement: A manufactured combination of limestone and a claylike substance for exterior or wet-atmosphere applications • Scratch coat: In three-coat plastering, the first coat, which is then scratched to provide a bond for the second, or brown, coat • Stucco portland cement: A type of plaster used in exterior applications • Three-coat plaster: The preferred application for all substrates; required over metal lath • Two-coat plaster: An acceptable application on gypsum lath and on the interior face of rough concrete block, clay tile, or porous brick FURRING AND LATH GYPSUM AND PLASTER LATH—TWO-HOUR FIRERATED PARTITION 7.264 Furring generally consists of channels or Z-shapes attached to the underlying wall (or structure for ceilings) for attaching gypsum or metal lath while allowing an air space. Resilient furring is often used on a cementitious substrate to reduce sound transmission. JOINT REINFORCEMENT 7.266 GYPSUM VENEER PLASTER Veneer plaster is applied as a thin plaster coat (skim coat) to a gypsum board surface. It provides a much harder surface than regular gypsum board and hides joints completely, making an ideal surface for paint. Blueboard—gypsum board with a blue paper face that bonds well with a plaster skim coat—comes in the same standard sheets as regular gypsum wallboard. Blueboard is finished by quickly taping and plastering the joints and then applying one or two coats of plaster, each about 1/8 in. (3 mm) thick, to the entire surface of the board. PLASTER OVER METAL OR GYPSUM LATH AND METAL STUDS 7.265 The final veneer plaster surface does not necessarily have to be painted; it can also be colored before application. Because veneer plaster can be applied immediately after joint treatment, and a second coat, if desired, can be applied soon after, the process is a oneday treatment, rather than the three days typically required for gypsum board installation. There is also no need to sand the surface and thus no dust to clean up. ORNAMENTAL PLASTER EXPANSION SCREEDS 7.267 Molding plaster is used for ornamental trim, running cornices, and other cast-plaster pieces. This specialty plaster has a very fine grain and is ideal for sharp detail when used for cast work. Plaster cornices can be reproduced by making a template of the piece’s profile. Smaller sections of decorative plaster ornamentation can be attached to larger cornices. A finished plaster cornice can weigh over 50 lb (23 kg). Contributors: The Marmon Mok Partnership, San Antonio, Texas. James E. Phillips, AIA, Enwright Associates, Inc., Greenville, South Carolina. Walter H. Sobel, FAIA, Walter H. Sobel and Associates, Chicago, Illinois. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 165 INTERIOR F INISHES TRADITIONAL CAST PLASTER 7.269 GLASS FIBER REINFORCED GYPSUM FABRICATION 7.270 GLASS FIBER REINFORCED GYPSUM GFRG FABRICATION PROCESS Glass fiber reinforced gypsum (GFRG), sometimes referred to as glass reinforced gypsum (GRG) or as fiberglass reinforced gypsum (FRG), is a remarkably lightweight, nontoxic, noncombustible composite of gypsum slurry and glass fiber. It is cast in molds at a manufacturing plant and shipped to the project site. GFRG products are cast in polyurethane or latex molds by either hand laying or spraying. The finish face of GFRG is smooth and resembles a plaster surface. The back-side appearance is bumpy and irregular, resembling the inside of a fiberglass boat hull, with glass fibers and structural members often visible. GFRG is used in such applications as column covers, decorative domes, coffered ceilings, and other architectural elements that were previously available only in plaster. GFRG manufacturing techniques can produce thin, high-strength shapes that are inherently flame resistant. GFRG is suitably lightweight for ceilings or other applications in which weight is a concern. Standard gypsum wallboard finishing techniques are required for installation. GFRG products can be field-cut for plumbing, electrical, mechanical, or other penetrations with the use of conventional gypsum board tools. Contributors: M. Kitty Myers, AIA, and Gabrielle Sapponara, Anshen & Allen, Architects, San Francisco, California. James E. Phillips, AIA, Enwright Associates, Inc., Greenville, South Carolina. The Marmon Mok Partnership, San Antonio, Texas. Casting Designs, Inc., Fort Worth, Texas. INTE R I O R CO N ST RU CT I O N 165 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 166 I N T E R IO R CO NST RU CTION Page 166 INTERIOR F INISHES CONIFEROUS AND DECIDUOUS TREES 7.273 GFRG COLUMN COVERS 7.271 WOOD SOURCES To conserve and preserve wood resources, choose certified wood, where possible. Composite and engineered wood salvaged from lumber production make use of otherwise wasted materials. Reclaimed woods can replace imported exotic hardwoods from unregulated sources and markets. Less wood can be used by minimizing job-site waste and with careful detailing. FOREST CERTIFICATION Wood in North America is increasingly available from certified forests. Major programs certifying forestland as sustainably and responsibly managed include: • Forest Stewardship Council (FSC): International organization that requires documentation of the chain of custody of wood products as well as product labeling. The FSC sanctions thirdparty certifiers. • Sustainable Forestry Initiative (SFI): Certification program run by the American Forest and Paper Association (AF&PA). • American Tree Farm System: Certification program for smaller, nonindustrial forest landowners. • Sustainable Forest Management Program: Developed by the Canadian Standards Association (CSA). RECLAIMED WOOD Reclaimed wood can be uniquely beautiful as well as environmentally friendly. Sources for reclaimed wood include: WOOD WALL FINISHES Wood is a renewable material that uses less energy to process than many other materials. It has low toxicity and is biodegradable. Wood may enhance thermal performance, interior acoustics, and even fire resistance. Imported wood and rare hardwoods may originate in noncertified, poorly managed forests, primarily in tropical countries. Veneers use rare materials more economically than in solid wood. Using woods from certified sustainable sources is the better choice. WOOD CLASSIFICATION Tree species are divided into two classes—softwood and hardwood—but these terms do not describe a wood’s hardness or density. Basswood, for example, is classified as a hardwood but is actually relatively easy to cut or scratch. Softwoods are defined as coniferous trees, evergreens that have needles instead of leaves. Softwoods, by far the more widely used type of wood, are used as framing lumber and in decorative moldings. Hardwoods are from deciduous trees, which have broad leaves that are shed each winter; these include fruit and nut trees. Hardwoods are often used as flooring and furniture components. HARDWOODS AND SOFTWOODS 7.272 SPECIES SOFTWOOD (S) OR HARDWOOD (H) HARDNESS Ash H Hard Basswood H Soft Beech H Hard Birch, yellow H Hard Cedar, western red S Soft Cherry, American black H Hard Fir, Douglas S Medium Hickory H Very hard Maple, hard H Very hard Maple, soft—“natural” H Medium Oak, English brown H Hard Oak, red H Hard Oak, white H Hard Pecan H Hard Pine, ponderosa S Medium Pine, southern yellow S Medium Redwood S Soft Teak H Hard Walnut, American Black H Hard Source: Adapted from AWI, Architectural Woodwork Institute, Reston, Virginia. • Demolition of old buildings • Dead, fallen, diseased, or nuisance trees in urban and suburban areas • Orchard trees cut for replacement • Careful reclamation of fallen trees from lakes and rivers • Usable wood safely reclaimed from demolition landfills • Wood by-products from secondary manufacturers SOLID WOOD Several different wood products are available for use in interior construction and furniture manufacturing. Traditional solid wood is giving way to the consistency and affordability of a variety of wood composite panels such as particleboard, plywood, medium-density fiberboard, and hardboard. Solid wood is used where durability and strength are of concern, for example, in countertop or table edges and chair legs. Unlike veneers or plastic laminates that must be replaced when damaged, solid wood can be sanded down and refinished. The method by which solid wood is sawn affects its appearance and usability: • Plain-sawn lumber, the most common type of sawn lumber, produces the least waste and requires the least labor. The cuts are made tangentially to the annual growth rings, which, when viewed from the end of the board, are 30° or less to the face of the board. • Quarter-sawn lumber, available in certain species, is more costly to produce than plain sawn. The growth rings, when viewed from the end of the board, are 60° to 90° to the face of the board. Quarter-sawn lumber is often preferred for wood flooring; because of its uniform surface, it tends to wear more evenly. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 167 INTERIOR F INISHES • Rift-sawn lumber is cut with the growth rings at 30° to 60° to the face of the board. In certain species, primarily oak, rift sawing produces flecks on the surface of the board. WOOD COMPOSITE PANELS Panel core products are architectural wood panels made from wood material that is cut or formed into sheet products. These are used alone (with or without a finish) or laminated together with other veneer products to make plywood. Panel cores serve as the substrate for laminates and veneers. The use of formaldehyde as a bonding material is a health concern; seek formaldehyde-free products or alternative materials. Panel core products suitable for architectural use include: • • • • Industrial-grade particleboard core Moisture-resistant particleboard core Fire-retardant particleboard core Medium-density fiberboard (MDF) core and moisture-resistant MDF core • Veneer core (plywood) • Hardboard core INDUSTRIAL-GRADE PARTICLEBOARD CORE To make industrial-grade particleboard core, heat and pressure are used to bond together synthetic resin or binder and wood particles of various sizes. Among its many uses are as a substrate for high-quality veneers and decorative laminates. When used as panels without any surface layers, the product is called particleboard. When used with wood veneer on the surface, the panels are referred to as particle core plywood. Particleboard core is classified into three densities, dependent on weight per cubic foot: • Low density: Less than 40 lb (18 kg) per cu ft (0.028 cu m) • Medium density: 40 to 50 lb (18 to 23 kg) per cu ft (0.028 cu m) • High density: More than 50 lb (23 kg) per cu ft (0.028 cu m) MOISTURE-RESISTANT PARTICLEBOARD CORE • Softwood plywood panels are made with softwood face veneers, and are used for underlayment or other concealed construction applications. They are seldom incorporated into finished architectural woodworking projects because of the instability of the core material and core voids. HARDBOARD CORE Hardboard is made of interfelted fibers consolidated under heat and pressure to a density of 31 lb (14 kg) per cu ft (0.028 cu m) or more. Available with either one side (S1S) or two sides (S2S) smooth, hardboard is often used for casework backs, drawer bottoms, and divider panels. Architectural woodworkers typically use two types of hardboard core: standard (untempered) and tempered, which is standard hardboard that has been subjected to a curing treatment to increase its stiffness, hardness, and weight. PANEL FACING MATERIALS Wood panel products are classified in two main facing material categories: decorative laminates/overlays and wood veneers. In panel construction, the thinner the facing material, the less force it can generate to cause warping. The thicker the substrate, the more it can resist a warping movement or force. DECORATIVE LAMINATES, OVERLAYS, AND PREFINISHED PANEL PRODUCTS This finish surface category can be broken down into the following broad groups: • High-pressure decorative laminates are formed under heat and pressure from resin-impregnated kraft paper substrates with decorative plastic face materials and a clear protective top sheet. This assembly, commonly called plastic laminate, offers resistance to wear and many stains and chemicals. Common uses include casework exteriors, countertops, and wall paneling. INTE R I O R CO N ST RU CT I O N 167 • Thermally fused decorative panels are flat pressed from a thermoset polyester or melamine resin-impregnated web, and most have been laminated to industrial particleboard or medium-density fiberboard substrates when they arrive at the woodwork fabricator. Performance is similar to that of high-pressure decorative laminates. Common uses include casework interiors, furniture, shelving, display materials, and decorative paneling. • Thermoplastic sheets are semirigid sheets or roll stock extruded from a nonporous combination of acrylic and polyvinyl chloride (PVC). The materials are impact resistant and minor scratches and gouges are less conspicuous due to the throughcolor property. • Medium-density overlays are made from pressed resin-impregnated paper overlays, and are highly resistant to moisture. They are available applied to cores suitable for both interior and exterior uses. The seamless panel face and uniform density offer a sound base for opaque finishes and paint. • Vinyl films, foils, and low-basis-weight papers are decorative facing materials that, although they have limited use in custom architectural woodworking, are suitable for some installations. WOOD VENEERS Wood veneers are produced in a variety of industry standard thicknesses. The slicing process is controlled by a number of variables, but the thickness of the veneer has little bearing on the quality of the end product. There are two types of veneers, hardwood and softwood. Hardwood veneers are available in many domestic and imported wood species and are normally plain sliced, but certain species can be rift sliced, quarter sliced, or rotary cut. Softwood veneers are usually sliced from Douglas fir, but pine and other softwoods are available. Most softwood veneer is rotary cut. Plain-sliced and quarter-sliced (vertical grain) softwoods may be obtained by special order. HARDWOOD PLYWOOD CORE TYPES 7.274 Moisture-resistant particleboard core is medium-density industrial particleboard that is bonded with resins that are more resistant to swelling when exposed to moisture. FIRE-RETARDANT PARTICLEBOARD CORE Medium-density industrial particleboard may be treated during manufacture to carry an Underwriters Laboratories (UL) Class A fire-rating stamp (flame spread 20, smoke developed 25). This material can be used as a substrate for paneling where a Class A rating is required. MEDIUM-DENSITY FIBERBOARD CORE MDF is made from wood particles reduced to fibers in a moderatepressure steam vessel and then combined with resin and bonded together under heat and pressure. The surface is flat, smooth, uniform, dense, and free of knots or grain pattern. MDF is useful as a substrate for paint, thin overlay materials, veneers, and decorative laminates. The homogeneous edge allows machining and paint finishes. MDF is one of the most stable mat-formed panel products and is widely used as an architectural panel. Some MDF is bonded with a moisture-resistant resin to produce a water-resistant product. VENEER CORE (PLYWOOD) CHARACTERISTICS OF CORE MATERIAL PERFORMANCE 7.275 PANEL CORE TYPE Industrial particleboard, medium density FLATNESS VISUAL EDGE QUALITY SURFACE UNIFORMITY DIMENSIONAL STABILITY SCREWHOLDING ABILITY BENDING STRENGTH AVAILABILITY Excellent Good Excellent Fair Fair Good Readily Readily Plywood is made up of wood or wood products that are sandwiched between two layers of wood veneer, top and bottom. Plywood is made up of alternating layers of thin veneer. Adhesive is placed between the layers, and the panels are pressed until the adhesive is set; heat is often used to speed the cure. The two outside layers, often selected for species, grain, and appearance, are called the face veneers. Medium-density fiberboard Excellent Excellent Excellent Fair Good Good Veneer core plywood Fair Good Fair Excellent Excellent Excellent Readily Lumber core plywood Good Good Good Good Excellent Excellent Limited Combination core, composite crossbands Excellent Good Excellent Good Excellent Excellent Limited Particleboard and MDF are commonly used as a core for plywood. Layers of wood veneer or solid lumber can also be used. There are generally two categories of plywood: Combination core, composite innerply Good Fair Good Good Good Good Limited Moisture-resistant particleboard Excellent Good Good Fair Fair Good Limited • Hardwood plywood panels are faced with hardwood or decorative softwood veneers over a core material such as mediumdensity particleboard, MDF, and low-density lumber. They are used for decorative purposes. . Moisture-resistant MDF Excellent Excellent Excellent Fair Good Good Limited Fire-rated particleboard Excellent Fair Good Fair Fair Good Limited 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 168 I N T E R IO R CO NST RU CTION Page 168 INTERIOR F INISHES The manner in which a log segment is cut in relation to the annual growth rings of the tree determines the appearance of the veneer. Individual pieces of veneer, referred to as leaves, are kept in the order in which they were sliced for reference during installation. The group of leaves from one slicing is called a flitch and is identified by a number and the gross square feet it contains. The faces of the leaves with relation to their position in the log are identified as the tight face (toward the outside of the log) and the loose face (toward the inside, or heart, of the log). line through the center of the log. A combination of cathedral and straight-grain patterns results, with a natural progression of pattern from leaf to leaf. Most veneers are taken from large trees, but some are sliced from fast-growing trees, dyed, and reglued in molds to create simulated grain patterns. The color of these reconstituted veneers is established during manufacture because the high percentage of glue line resists staining. Rift-cut veneers are produced most often in red and white oak, rarely in other species. Note that rift veneers and rift-sawn solid lumber are produced so differently that a match between them is highly unlikely. In both cases, the cutting is done slightly off the radius lines, minimizing the fleck associated with quarter slicing. TYPES OF VENEER CUTS Plain, or flat, slicing is most often used to produce veneers for high-quality architectural woodwork. Slicing is done parallel to a Quarter slicing, roughly parallel to a radius line through the log segment, simulates the quarter-sawing process used with solid lumber. In many species, the individual leaves are narrow as a result. A series of stripes is produced, varying in density and thickness among species. In red and white oak, fleck (sometimes called flake) is a characteristic of this slicing method. RIFT-SLICED (RIFT-CUT) VENEER 7.278 PLAIN-SLICED (FLAT-SLICED) VENEER 7.276 ROTARY-CUT VENEER 7.279 QUARTER-SLICED VENEER 7.277 VENEER MATCH TYPES 7.280 To create rotary-cut veneers, the log is center mounted on a lathe and peeled along the path of the growth rings, like unwinding a roll of paper. This provides a bold, random appearance. Rotary-cut veneers vary in width, so matching at veneer joints is extremely difficult. Most softwood veneers are cut this way. Rotary-cut veneers are the least useful in fine architectural woodwork. MATCHING BETWEEN ADJACENT VENEER LEAVES It is possible to achieve certain visual effects by the manner in which the veneer leaves are arranged. Rotary-cut veneers are difficult to match; therefore, most matching is done with sliced veneers. Book matching: This is the most commonly used match in the industry. Every other piece of veneer is reversed so adjacent pieces (leaves) are opened like the pages of a book. Because the tight and loose faces alternate in adjacent leaves, they reflect light and accept stain differently. The veneer joints match, creating a symmetrical pattern that yields a maximum continuity of grain. Slip matching: Adjoining leaves are placed (slipped out) in sequence without being turned; thus, all of the same face sides are exposed. The grain figure repeats but joints do not show grain match. Random matching: Veneer leaves are placed next to each other in a random order and orientation, producing a casual board-byboard effect in many species. Conscious effort is made to mismatch the grain at joints. End matching: This method is often used to extend the apparent length of available veneers for high wall panels and long conference tables. End matching occurs in two types: • Architectural end match: Leaves are individually book or slip matched, alternating end to end and side to side. Architectural end matching yields the best continuous grain patterns for length as well as width. • Panel end match: Leaves are book or slip matched on panel subassemblies, with sequenced subassemblies end matched, resulting in some modest cost savings on projects, where applicable. For most species, panel end matching yields a pleasing, blended appearance and grain continuity. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 169 INTERIOR F INISHES Running match: Each panel face is assembled from as many veneer leaves as necessary. This often results in an asymmetrical appearance, with some veneer leaves of unequal width. Balance matching: Each panel face is assembled from an odd or even number of veneer leaves of uniform width before edge trimming. Balance and center matching: Each panel face is assembled from an even number of veneer leaves of uniform width before edge trimming. Thus, there is a veneer joint in the center of the panel, producing horizontal symmetry. SPECIAL WOOD VENEER MATCHING OPTIONS 7.281 INTE R I O R CO N ST RU CT I O N 169 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 170 I N T E R IO R CO NST RU CTION WOOD FINISHING Finishing operations include the application of stains and a protective topcoat. Finishing protects the wood surface from permanent staining by sealing the pores; it also guards against damage to the wood surface caused by heat, dirt, and spills, and enhances the beauty of the wood grain and color. Concerns regarding volatile organic compounds (VOCs) have led to the development of water-based finishes. Recent improvements have increased the clarity and durability of these wood finishes. STAINS Stains are transparent or opaque coatings that penetrate and color a wood surface without masking its inherent grain. Stains can be used to change the color of a piece of wood. For example, mahogany is usually stained a deep red-brown to modify its natural light orange color. Sometimes wood is stained to resemble a different species. LACQUERS Lacquers dry by the evaporation of their strong solvents. The solvents evaporate so fast that lacquers are typically spray applied, rather than brushed on. Lacquers may or may not contain pigments and are the most popular commercial furniture and casework finishes. Standard, or noncatalyzed, lacquers can be touched up easily or recoated, because the solvent in each coat slightly dissolves the previous coat, forming a monolithic finish. They are the most commonly used furniture finishes. Page 170 INTERIOR F INISHES Catalyzed lacquers, like noncatalyzed lacquers, contain nitrocellulose. They dry faster than standard lacquers, so dust is even less likely to settle on the curing coat and contaminate the finish. Catalyzed lacquers are harder than standard lacquers and are moderately easy to touch up. They are very hard and brittle and tend to splinter and spiderweb. TYPICAL USES VARNISHES Varnishes cure by evaporation of the solvents, oxidation of the oil, or both. Polyurethane, added to make a varnish resistant to water and alcohol, is often used as a wood floor finish. Conversion varnishes, like the lacquers, are very durable and fast drying, forming thick coats. They have superb resistance to a variety of common chemicals. Wood panels 1 in. (25 mm) thick or less may be solid lumber panels or made from veneer over plywood or composition boards. The stiles and rails are typically made from solid wood or veneered boards. Rim and lip moldings and other trims are made almost exclusively from solid wood. Acrylic and vinyl lacquers are available, which do not have a nitrocellulose base, as do noncatalyzed and catalyzed lacquers. POLYESTER AND POLYURETHANE FINISHES Polyester and polyurethane coatings are known for their excellent chemical resistance and very durable, dense, and smooth finishes. When pigmented, they resemble high-pressure decorative laminates. They require special skill and equipment for application and are expensive. Spectacularly shiny gloss levels can be achieved with these coatings. Polyesters are basically 100% solids once applied and are extremely difficult to touch up. Like polyesters, polyurethanes exhibit hardness and excellent resistance to chemicals but are much easier to apply. ADVANTAGES DISADVANTAGES Lacquer, nitrocellulose Interior trims, furniture, paneling, ornamental work Repairable, widely available, quick drying Low durability and resistance to most solvents and water, yellows over time Lacquer, precatalyzed Interior furniture, casework, paneling, ornamental work, stair parts (except treads), frames, windows, blinds, shutters, doors Repairable; stain, abrasion, and chemical resistance Some yellowing, moderate build Lacquer, postcatalyzed Same as above Repairable; finish clarity; stain, heat, abrasion, and chemical resistance Same as above Latex acrylic, water based Same as above Low VOCs, finish clarity for some types, stain and yellowing resistance Low durability and solvent and heat resistance, slow drying time Varnish, conversion Interior furniture, casework, paneling, ornamental work, stair parts, frames, windows, blinds, shutters, doors Durable, widely available, good build Occasional lack of finish clarity Oil, synthetic penetrating Furniture or trims requiring a very low sheen or close-to-wood appearance Close-to-wood, antique look, low sheen Labor-intensive application and maintenance, occasional refreshing finish required, low resistance to most substances Vinyl, catalyzed Interior kitchen, bath, office furniture, and laboratory casework Durable, widely available, fast drying Occasional lack of finish clarity Acrylic, cross-linking, water based Interior furniture, casework, paneling, ornamental work, stair parts, frames, windows, blinds, shutters, doors Durable; excellent abrasion, solvent, stain, and chemical resistance; moisture resistant; moderately fast drying Possible discoloration over time UV curable, acrylated epoxy, polyester, or urethane Interior doors, paneling, flooring, stair parts, and casework where applicable; consult finisher before specifying Low VOCs, durable, nearly 100% solids usage, quick cure With UV finish, requires handheld UV lamp to repair; easy repair with lacquers or conversion varnish UV curable, water based Same as above Low VOCs, quick cure Same as above Polyurethane, catalyzed Interior floors, stairs, high-impact areas, Durable, good build some doors, some exterior; generally not used for casework, paneling, windows, blinds, shutters Slow drying, very difficult to repair; some formulas hazardous to spray-apply without makeup suits Polyurethane, water based Interior furniture, casework, paneling, ornamental work, stair parts, frames, windows, blinds, shutters, doors Improved durability; excellent abrasion, solvent, stain, and chemical resistance; moderately fast drying; moisture resistant Tannins in some wood species may cause discoloration over time Polyester, catalyzed Interior furniture, casework, paneling, ornamental work, windows, blinds, shutters, some doors Durable, good build, can be polished Not widely available, slow curing, requires special facilities and skills, very difficult to repair, brittle, inflexible finish NOTE 7.282 Finishes are available transparent or opaque, except for oil, synthetic penetrating, which is transparent only. WOOD PANELING Wood paneling consists of a series of thin sheets of wood panels framed together by strips of wood, vertical stiles, and horizontal rails. Wood paneling includes shop-fabricated wall paneling that may be fabricated as solid lumber paneling, wood veneer paneling, and plastic laminate–faced wood paneling. Board paneling fabricated from standard profile boards is considered finished carpentry, and should not be confused with wood paneling, classified as architectural woodwork. WOOD FINISHING SYSTEMS 7.282 SYSTEM WOOD WALL PANELS Mortise and tenon or doweled joints are used to join stile to rail. Stile-to-stile joints at outside corners are spline joints or lock miters; inside corners are butt jointed. Because of its stability, plywood is preferable to solid lumber or other materials as backup. STILE/RAIL TO PANEL JOINERY 7.283 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 171 INTERIOR F INISHES WAINSCOT WITH RAISED PANEL AND FLUSH MOLDING—SECTION 7.284 Contributors: Greg Heuer, Architectural Woodwork Institute, Potomac Falls, Virginia. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. FULL-HEIGHT WALL PANEL—SECTION 7.285 INTE R I O R CO N ST RU CT I O N 171 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 172 I N T E R IO R CO NST RU CTION CURVED PANELED WALL 7.286 NOTE 7.286 AFLAC Customer Service Center in Columbus, Ohio. The woodworker was Columbus Cabinet Company, Columbus, Ohio. The project was originally published in Design Solutions, Winter 2000. Designed by Hecht, Burdeshaw, Johnson, Kidd & Clark, Columbus, Georgia, and Opelika, Alabama. Page 172 INTERIOR F INISHES 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 173 INTERIOR F INISHES WOOD ADHESIVES Synthetic adhesives for bonding metals, concrete, glass, rubber, plastics, and wood are used to manufacture products such as plywood, oriented strand board (OSB), and laminated timbers. They can also be used during construction to adhere ceramic tiles to floors or walls and to attach gypsum board and other construction products. TYPICAL WINDOW TRIM 7.288 Currently, most adhesives use organic solvents, but water-based adhesives are gaining in popularity because they do not emit harmful vapors, are easy to clean up, and can be discarded as regular trash. Many jurisdictions are enacting clean air statutes that, among other things, target organic solvents as air pollutants. Organic solvents also can have adverse effects on the workers who apply them, as well as on future building occupants. One drawback to most water-based adhesives, however, is that they tend only to resist water, whereas the solvent-based adhesives are waterproof. INTERIOR WOOD TRIM Wood trim is, generally, a decorative treatment applied after wall, floor, and ceiling finishes have been installed. It can be made of flat or molded wood, and can consist of single pieces of wood or be built up of several pieces that give a more complex and decorative appearance. Trims made of MDF with durable plastic finishes are also available. Interior trim conceals joints between different materials and blocks air infiltration through walls, which typically is greatest at material joints. Interior trim also frames wall and ceiling openings (door and window/skylight trim), defines planar edges (crown and base molding), and acts as a visual divider between dissimilar materials (chair rail). TYPICAL CASING PROFILES 7.289 The Architectural Woodwork Institute differentiates wood trim according to its length: Standing trim refers to the trims of fixed length delivered to the job site (i.e., door jambs and casings, window stools, etc.); running trim refers to the trims of random, longer length delivered to the job site (i.e., base, chair rail, crown molding, etc.). COPED, SCARF, AND MITER JOINTS 7.287 TYPICAL WOOD TRIM AND MOLDING 7.290 Contributor: Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. INTE R I O R CO N ST RU CT I O N 173 TYPICAL DOOR CASING AND BASE TRIM 7.291 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 174 I N T E R IO R CO NST RU CTION Stools are used as interior caps on windowsills and may receive casing from above and an apron below. They are specified by the width of the rabbet and the degree of the bevel. TYPICAL STOOLS 7.292 Page 174 INTERIOR F INISHES Cap or rake moldings are used above door and window heads and at the top of wainscots. TYPICAL COVE MOLDINGS 7.298 TYPICAL CAP OR RAKE MOLDINGS 7.295 Bed moldings are similar in use and size to cove moldings and may be used at the bottom of built-up cornices and at other vertical-tohorizontal junctions. Base moldings are used to trim the intersections of a wall or cabinet and the floor. Base may be one piece (with an integral base cap) or flat with an optional base cap. Separate caps and shoes are flexible and facilitate a close fit to uneven wall and floor surfaces. Crown moldings are applied alone at the joint between the wall and ceiling, or together with other moldings in a built-up cornice, typically toward the top of the cornice assembly; they are measured edge to edge. TYPICAL BED MOLDINGS 7.299 TYPICAL CORNICE TRIM 7.296 TYPICAL BASE MOLDINGS 7.293 Often integrated with cornices, picture moldings are used as continuous projecting supports for hanging picture rail hooks. Picture rail hooks are available to fit these profiles. TYPICAL PICTURE MOLDINGS 7.300 Stops are applied to the jamb to guide operable window sashes and stop doors in a closed position. Stops may also be used as a component of built-up moldings, typically base or cornice moldings. TYPICAL STOPS 7.394 TYPICAL CROWN MOLDINGS 7.297 Panel strips, battens, and astragals are used in panels to conceal joints, over window jamb edges in multiple-opening windows, and as astragals at meeting joints of double-leaf doors. TYPICAL PANEL STRIPS, BATTENS, AND ASTRAGALS 7.301 Cove moldings are similar to crown moldings, but may be smaller in size and have less detail. Cove moldings are also used at inside corners, such as wall to wall or ceiling to wall or as a component of built-up moldings. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 175 INTERIOR F INISHES Chair rails were originally meant to protect the wall surface from chair backs. Chair rails should be located to align with the chair backs in the room, either alone or atop wainscot paneling. INTE R I O R CO N ST RU CT I O N 175 WALL TILE TYPES Ceramic wall tiles are modular surfacing units of fired clay and TYPICAL BACKBANDS 7.305 other ceramic materials. They provide a permanent, durable, waterproof surface for interior walls, and are available in bright or matte glazes in a wide range of colors and surface designs. Wall tiles are usually 5/16 in. (8 mm) thick. They are available in square, hexagon, and octagon shapes, as well as some custom shapes. TYPICAL CHAIR RAILS 7.302 Glazed ceramic wall tiles have a nonvitreous body and bright, matte, or crystalline glazes that are impervious to water. Decorative thin wall tile is glazed tile with a thin, usually nonvitreous body intended for decorative interior residential use. Because it is not resistant to breakage, it is not recommended for commercial applications or use on floors. TYPICAL PANEL MOLDINGS 7.306 Cementitious backer boards made of portland cement or treated gypsum and lightweight aggregate can be used under thinset tile and as a water-resistant base for tile regularly exposed to water (such as a shower surround). Standard sizes for ceramic wall tiles include: • 4-1/4 by 4-1/4 in. (108 by 108 mm) • 4-1/4 by 6 in. (108 by 152 mm) • 6 by 6 in. (152 by 152 mm) Half-rounds are used to conceal vertical and horizontal joints. Quarter-rounds are used at inside corners and as base shoes. Base caps are applied at the top of the baseboard, flush against the wall. Backbands are typically applied as trim at the outer edge of door and window jambs and heads, to form a built-up two-part casing. Panel moldings are typically used as door and wainscot trim, mitered together and arranged in rectangles. TYPICAL ROUNDS AND BASE CAPS 7.303 Small ceramic mosaic tiles with a porcelain or natural clay body are used glazed or unglazed for walls. These small tiles are usually face- or back-mounted on sheets to make handling easier and installation quicker. Standard and custom designs can be ordered. TILE WALL FINISHES Specialty wall tiles include glass tiles, handmade and custom tiles, and special sizes. CERAMIC TILE Ceramic tile is fabricated from clay or a mixture of clay and ceramic materials. Natural clay is most commonly used, but porcelain is also available. Porcelain tile is fine grained and smooth. It can be formed into sharply detailed designs. Tile dimensions are typically nominal. Ceramic tile thickness is usually 3/8 or 1/2 in. (10 or 13 mm). Refer to the manufacturer’s data for specific tile and trim piece dimensions. WALL TILE TRIM SHAPES Ceramic wall tiles come in a variety of trim shapes for finished angles and edges. A sanitary base is a coved tile set at the intersection of the floor and wall. Its curved angle helps to prevent dirt from accumulating and makes cleaning easier. Ceramic wall tile trim pieces include: ANSI A137.1, Specifications for Ceramic Tile, quantifies the four levels of water absorption for tile. The density and porosity of the tile determine its capability to absorb moisture. In general, the lower the water absorption level, the better the stain resistance of the tile. TILE COMPOSITION AND GLAZE Ceramic tile is made from either natural clay or porcelain, and is glazed or unglazed. TYPICAL OUTSIDE CORNER TRIM 7.304 • Porcelain tile is a ceramic mosaic or paver tile generally made by the dust-pressed method. It is dense, impervious, fine grained, and smooth with a sharply formed face. • Natural clay tile is a ceramic mosaic or paver tile with a distinctive, slightly textured appearance. It is made by the dustpressed or plastic method from clays that have a dense body. • Glazed tile has an impervious facial finish of ceramic materials that is fused to the body of the tile. The body may be nonvitreous, semivitreous, vitreous, or impervious. • Unglazed tile is a hard, dense tile of uniform composition that derives color and texture from the materials used in its fabrication. Bead: Rounded horizontal bead for top edges Bullnose: • Surface bullnose with a flat bottom and eased top edge • Surface cap with a flat bottom and rounded top edge, used horizontally or vertically • Corner bullnose with two rounded finished edges to complete a corner where horizontal and vertical bullnoses meet Curb: Tile curb for horizontal use Base: • Cove base to connect to floor tile • Stack-on cove base with coving on the bottom and a flat edge on the top to accommodate wall tile • Rounded top cove base, used where wall tile is not installed above the base • Surface base with a coved lower edge and an eased top edge WATER ABSORPTION OF CERAMIC TILE 7.307 TYPE Contributors: Greg Heuer, Architectural Woodwork Institute, Potomac Falls, Virginia. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. Corky Binggeli, Materials for Interior Environments, John Wiley & Sons, Hoboken, NJ, 2008. WATER ABSORPTION CERAMIC MATERIAL Natural clay USE Nonvitreous More than 7% Not for use in continually wet locations Semivitreous More than 3%, but not more than 7% Natural clay Not for use in continually wet locations Vitreous 0.5 to 3% Natural clay For use in continually wet locations Impervious 0.5% or less Porcelain For use in continually wet locations; superior wear resistance 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 176 I N T E R IO R CO NST RU CTION Page 176 INTERIOR F INISHES ONE-COAT METHOD 7.311 WALL TILE TRIM SHAPES 7.308 DRYSET MORTAR (CEMENTITIOUS MORTAR) 7.312 TILE INSTALLATION There are two basic steps in tile installation: setting and grouting. Setting fixes the tile to the substrate with mortar or adhesive. Grouting fills in the spaces between the tiles, binding them into a continuous surface. Tile, mortar, and grout selection are interdependent. Ceramic wall tile may be applied with either the thinset or the thickset process. Grouts for wall tiles are available in a wide variety of colors. Highly pigmented grouts may bleed onto contrasting colored tiles. CEMENT MORTAR 7.309 THICKSET INSTALLATION COATED GLASS-MAT BACKER BOARD 7.313 Thickset installations use portland cement. A mortar bed is laid 3/4 to 2 in. (19 to 51 mm) thick. Accurate floor slopes to drains can be installed, and reinforcement with metal mesh or waterproof membranes is possible. Waterproof membranes are flexible sheets or liquids that cure to a seamless membrane; they are used in applications that are regularly or continually exposed to water. Both thickset and thinset installations can incorporate waterproof membranes. THINSET INSTALLATION Thinset installations are the most popular (accounting for approximately 90% of installations in the United States) and can be as thin as 3/32 in. (2.4 mm). All methods other than conventional portland cement applications are considered thinset. Bonding materials include dryset mortar, latex portland cement mortar, organic adhesive, epoxy mortar or adhesive, and modified epoxy emulsion mortar. Thinset application requires a continuous, stable, and undamaged surface. Cementitious backer boards are sometimes used as an underlayment for thinset installations. Cementitious backer boards are made of portland cement or treated gypsum and lightweight aggregate, and are designed to provide a water-resistant base for ceramic tile installations regularly exposed to water, for example, a shower surround. MORTAR Mortars are categorized as cementitious and noncementitious. Adhesives are also popular for use in fixing tiles to the substrate. The one-coat method is used for remodeling or on surfaces that present bonding problems. It is the preferred method of applying tile over gypsum plaster or gypsum board in showers and tub enclosures. Coated glass mat backer board is used in wet areas over dry, wellbraced wood or metal studs. Stud spacing should not exceed 16 in. (406 mm) on center, and metal studs must be 20 gauge or heavier. NOTE 7.309 Use cement mortar over masonry, plaster, or other solid backing to provide firm anchorage for a metal lath. This is the preferred method for showers and tub enclosures, and is used in remodeling. Contributor: Tile Council of North America, Inc., Anderson, South Carolina LATEX PORTLAND CEMENT MORTAR 7.310 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 177 INTERIOR F INISHES SETTING MATERIALS 7.314 TYPE INTE R I O R CO N ST RU CT I O N 177 MOVEMENT JOINTS 7.315 DESCRIPTION FEATURES CEMENTITIOUS Portland cement mortar Portland cement and sand, in proportions of 1:5 for floors; portland cement, sand, and lime, in proportions of 1:5:1/2 to1:7:1 for walls Most surfaces, ordinary installations Dryset mortar Portland cement with sand and additives imparting water retention; used as a bond coat for setting tile Thinset installations Latex portland cement mortar Portland cement, sand, and special latex additive; used as a bond coat for setting tile Latex additives improve adhesion, reduce water absorption, and provide greater bond strength and resistance to shock and impact; required for large-unit porcelain-bodied tile Epoxy mortar Epoxy resin and epoxy hardeners Chemical resistant Modified epoxy emulsion mortars Emulsified epoxy resins and hardeners with portland cement and silica sand High bond strength; little or no shrinkage; not chemical resistant NONCEMENTITIOUS Furan resin mortar Furan resin and furan hardeners Chemical resistant Epoxy adhesives Epoxy resin and epoxy hardeners High bond strength and ease of application; not optimal chemical resistance Organic adhesive For interior use only; ready to use (no addition of liquid); cures by evaporation Not suitable for continuously wet applications or temperatures exceeding 140°F GROUT MOVEMENT JOINTS Grout is used to fill joints between tiles and is selected with a compatible mortar. Grout is either a portland cement–based mixture or a mixture of other compounds to enhance its performance or ease its installation. The type and size of tile, service level, climatic conditions, tile spacing, and individual manufacturer’s recommendations are factors that should be considered when selecting grout. Movement in the structure and the substrate must be accommodated by the ceramic tile installation. For quarry tile and paver tile, the movement joint width should be the same as the grout joint, but not less than 1/4 in. (6 mm); for ceramic mosaic tile and glazed wall tile, the movement joint should be at least 1/4 in. (6 mm), but never less than 1/8 in. (3 mm). In addition to expansion joints, there are several types of movement joints, as follows: Portland cement–based grout is a mixture of portland cement and sand (for floors) or lime (for walls) and is used for thickset installations. Portland cement–based grouts include commercial portland cement grout, sand portland cement grout, dryset grout, and latex portland cement grout. Grouts based on mixtures of other compounds include solid epoxy, furan, silicone, and mastic grouts. Mastic grout eliminates the need for mixing on-site. • Epoxy grout is a two- or three-part mixture (epoxy resin hardener with silica sand filler) that is highly resistant to chemicals and has great bond strength. This grout and furan grout are made for different chemical and solvent resistance. • Furan resin grout is a two-part furan mixture (similar to furan mortar) that resists high temperatures and solvents. • Silicone rubber grout is an elastomeric mixture of silicone rubber. It has high bond strength, is resistant to water and staining, and remains flexible under freezing conditions. Silicon, urethane, and modified polyvinyl chloride are used in pregrouted ceramic tile sheets. • Control joints or contraction joints are formed, sawed, or tooled grooves in the concrete substrate, used to create a weakened location where the controlled cracking of the concrete can occur. • Construction joints are located where two separate placements of concrete meet and where reinforcement may be continuous. • Isolation joints are installed where adjoining areas of a concrete substrate may move in three directions and where the formation of cracks is to be avoided. • Cold joints are formed when the size of a concrete slab is too large for one pour, and successive pours are required. Cold joints may crack with movement of the slab. Some slabs are saw cut at regular intervals to provide controlled cracking locations. MATERIALS Movement joints in tile installations use backup strips or sealants. Backup strips are flexible and compressible types of closed-cell foam polyethylene, butyl rubber, or open-cell and closed-cell polyurethane. These strips should be rounded at the surface that contacts the sealant. Sealants used are silicone, urethane, or polysulfide. Silicone sealants are used on interior vertical tile surfaces. Mildew-resistant silicone sealants are useful in wet areas. Urethane sealants are used in interior horizontal tile installations. LOCATIONS All expansion, control, construction, cold, and seismic joints in the structure should continue through the tile work, including such joints in vertical surfaces. Joints through tile work directly over structural joints must never be narrower than the structural joint. Expansion joints should be installed in the following circumstances: • In general, 24 to 36 ft (7.3 to 11 m) in each direction • For tile work exposed to direct sunlight or moisture, 12 to 16 ft (3.7 to 4.9 m) in each direction • Where tile work abuts restraining surfaces such as perimeter walls, dissimilar floors, curbs, columns, pipes, ceilings, and where changes occur in backing materials Contributors: Tile Council of North America, Inc., Anderson, South Carolina. Winnie Cheng, Rhode Island School of Design, Providence, Rhode Island. Jess McIlvain, AIA, CCS, CSI, Jess McIlvain and Associates, Bethesda, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 178 I N T E R IO R CO NST RU CTION Page 178 INTERIOR F INISHES GLASS TILE WALL FINISHES STONE WALL FINISHES Glass tile is impervious to water and is heat and thaw resistant. It can be used on walls of all types, as well as on floors, countertops, and exterior and underwater surfaces. Applications include kitchen backsplashes, showers and baths, saunas and steam rooms, as well as feature walls and columns in residential and commercial spaces. Glass tile surfaces are easily cleaned with pH-balanced soap and water or mild tile cleaners. TYPES OF STONE GRANITE Granite can be used on interior walls in many finishes, ranging from highly polished to a rough thermal finish. A waterjet finish is a texture between honed and thermal that brings out the color of the stone. It will appear slightly darker than a thermal finish. Granite is much harder than marble, and is therefore more costly to fabricate and finish. TYPES There are four main types of glass tiles: Fused glass consists of clear or translucent glass backed by a visible opaque color layer. Fused glass is available in many small and large sizes, and is often etched or coated. Cast glass is made by putting chunks of glass into a mold and heating them until they melt together, creating a layered appearance. It is used for most recycled glass products. Sintered glass is made from glass powder pressed into dies and heated to fuse the particles. Color is added to the powder or applied to the milky, scratch-resistant surface. Tiles are usually 1 by 1 in. (25 by 25 mm), but may be up to 3 by 3 in. (76 by 76 mm). Smalti are small hand-cut pieces of textured tiles used primarily for art mosaics. They are made from a glass paste or glaze of silicon melted with sodium or potassium carbonate. Metals are added for stability and metal oxides for color. The two most common surface treatments for glass tiles are: Slumping: Glass (usually plate glass) is curved into convex or concave shapes by firing in relief molds at relatively low temperatures. Etching: A thin, translucent layer is produced on the surface of the tile by one of three methods: • Abrasion by sandblasting or laser cutting • Acid etching with a chemical such as hydrofluoric acid • Application of an additional cloudy glass surface on top of the tile METAL WALL TILES Metal tiles can be used on walls, but are generally not recommended for floors, where they are liable to being scratched and can be permanently damaged. Installation in showers, bathrooms, and kitchen areas where puddling may occur is not recommended. Metal tiles should not be used around pools, wet or dry saunas, or fountains, where they may be damaged by chemicals in water. Avoid their use on countertops where they may come into contact with acid juices, colas, or damaging cleaners. Metal tiles conduct heat, and should be installed a minimum of 41/2 in. (115 mm) from stove burner elements, and at least 6 in. (152 mm) from fireplace openings. STONE FACING Numerous types of stones can be used for stone facing; however, consideration should be given to the selection of a stone that is appropriate for the intended use. Stone facing is available in two basic types: dimension stone panels and dimension stone tiles. Marbles and other stones that might be considered too soft for flooring can usually be used for stone facing, with the proper reinforcement and installation. DIMENSION STONE PANELS MARBLE Marble varieties that are not recommended for exterior use can be successfully used in interior wall panel applications, if properly prepared for vertical installations. Heavily veined marbles, prized for their aesthetic qualities, are examples. SERPENTINE MARBLE Green varieties of marble, called serpentine marble, are sensitive to water and are prone to warping when wet. When installing serpentine stone, use setting materials that do not contain water, such as water-cleanable epoxy adhesives. GREENSTONE Greenstone, a general term for metamorphosed igneous basaltictype rock, is typically available in honed or cleft finishes, and is not suitable for a highly polished finish, due to the stone structure. Greenstone contains minerals that give it a green appearance: actinolite, chlorite, or epidote. DOLOMITIC LIMESTONE Dimension stone is defined as quarried stone with usually one or more mechanically dressed surfaces. These are thick slabs of stone that are marked as they are cut for matched-pattern installations, such as book-matched or end-matched configurations. Dimension stone facing panel dimensions typically range from larger-dimension units with face areas up to 48 sq in. (310 sq cm), and 3⁄4 in. (19 mm) or more thick. DIMENSION STONE TILES Stone tiles are fabricated under different conditions from dimension stone panels and are not typically matched to create patterns, such as book matching or end matching. The greater variation in stone color, pattern, and texture is common in stone tile. Stone tile modules are dimension stone units that do not exceed 4 sq ft (0.37 sq m) and are less than 3⁄4 in. (19 mm) thick. Stone tiles are typically 12 by 12 in. (305 by 305 mm) up to 24 by 24 in. (610 by 610 mm), and 1⁄4, 3⁄8, or 1⁄2 in. (6, 10, or 13 mm) thick. They are usually furnished with a protective backing such as fiberglass to improve their strength. Dolomitic limestone is more widely used for interior stone facing, as it is typically not as porous as oolitic limestone (which contains small spheres of calcium carbonate formed around sand grains or shell fragments), and is often polished similar to marble. It is also available with a smooth honed finish, a textured sandblasted finish, or a split-face finish. Granite and marble stone tiles 1/4 to 1/2 in. (6 to 13 mm) thick are available, usually with a face dimension of 12 by 12 in. (305 by 305 mm). Tiles can be directly applied to a wall with adhesive or thinset mortar, similar to flooring applications. Tiles are not recommended for walls over 8 ft (2.4 m) high. SLATE MARBLE WALL FACING Patterns Slate is commonly used as a contemporary interior floor or wall finish. It is available in a palette of dark, rich colors, including green, black, purple, and red. Slate splits easily into thin sheets. The finish resulting from the natural face is referred to as a cleft finish. Slate can also be sand rubbed to a smooth or honed finish. TRAVERTINE Travertine is distinguished by its natural cavities, formed by plants embedded during the rock’s formation, which must be filled to achieve a smooth surface. Filling materials are typically portland cement, epoxy resins, or polyester resins. Travertine is actually a kind of limestone, but some types that take a polish are classified as marble. It is popular for use as flooring because its visual texture conceals dirt much better than most other stones. Stone with distinctive texture and markings, such as certain marbles, lends itself to specific pattern arrangements. The markings vary depending on whether the marble veneer is cut with or across its setting bed. Dimension stone panels are available in the following patterns: • Blend pattern: Panels of the same variety of stone but not necessarily from the same block are arranged at random. • Side-slip pattern: Panels from the same block are placed side by side or end to end in sequence, to ensure a repetitive pattern and blended color. • End-matched pattern: Adjacent panel faces are finished, and one panel is inverted and placed above the other. • Book-matched pattern: Adjacent panel faces are finished, and one panel is placed next to the other. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 179 INTERIOR F INISHES MARBLE WALL FACING PATTERNS 7.316 INTE R I O R CO N ST RU CT I O N 179 TYPICAL FINISHES AND COMMON SIZES OF INTERIOR STONE WALL PANELS 7.317 STONE GRADE FINISH MINIMUM THICKNESS MAXIMUM FACE DIMENSION NOTES Granite Building (exterior) Veneer Masonry Polished Honed 3/4 to 1-1/4 (19 to 31 mm) 5-0 5-0 (1,524 1,524 mm) This very hard and durable surface is not likely to stain. Many colors and grains are available. Marble Group A (exterior) Group B Group C Group D Polished Honed 1/2 to 7/8 (13 to 22 mm) 4-0 7-0 (1,219 2,134 mm) The most colorful and interesting marbles are in Groups B, C, and D; however, some filling of natural voids may be required. Many colors and patterns are available. Limestone Select Standard Rustic Variegated Smooth Tooled Polished 7/8 to 3 (22 to 76 mm) 4-0 9-0 (1,219 2,743 mm) Soft and easy to shape, but shows wear and may discolor over time. Colors range in the buffs and grays. Slate Ribbon Clear Natural Cleft Sand Rubbed Honed 1 to 1-1/2 (25 to 38 mm) 2-6 5-0 (762 1,524 mm) Ribbon stock is distinguished by its ornamental integral bands, which are usually darker than the rest of the stone. Colors range in the pastel hues. INSTALLATION OF STONE PANELS ANCHORING SYSTEMS BASE DETAIL 7.320 Wire-tie anchoring systems with plaster or mortar spots are the traditional methods for installing interior stone facing. Mechanical anchoring systems fasten stone directly to the backup wall, eliminating the need for additional studding and gypsum board and providing verifiable seismic restraint. STONE FACING WIRE ANCHOR CONNECTION 7.318 STONE PANEL ON WOOD STUDS 7.321 SOFFIT DETAIL AT WALL 7.319 . 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 180 I N T E R IO R CO NST RU CTION WIRE ANCHORED TO METAL STUD 7.322 Page 180 INTERIOR F INISHES MORTAR BEDS Mortar beds can be used when installing thin stone tiles and thin panels in a thick portland cement mortar system consisting of metal lath, a scratch coat, and a float coat. The stone tile is set into the float coat. THINSET BEDS Thinset installations are appropriate for vertical application of stone tiles and thin panels up to 1⁄2 in. (13 mm) thick. The stone is set in the same manner as ceramic tiles, directly on the substrate of gypsum board or cementitious backer units, using specific thin-bed setting systems. Adhesives used with thinset installations should be nonstaining, especially when installing light-colored stone. TYPICAL HORIZONTAL JOINTS 7.324 WIRE AND BOX ANCHOR TO GYPSUM BOARD 7.323 Mechanical Anchoring Systems In mechanical anchoring systems, the stone is kerfed (grooved or notched) on the back side and is restrained by the use of straps or clips. Anchor systems may be fastened to metal studs through gypsum board. Exterior anchors may also be used with metal channel struts, eliminating the need to coordinate stud locations with anchor locations. This type of anchor may still require plaster-setting spots. INSTALLATION OF STONE TILE Stone tile may be installed in a full mortar bed, in a thinset mortar bed, or with an adhesive. Thin stone tiles are typically not restrained by ties or anchors; therefore, their installation has limitations. Tiles that are installed above 8 ft (2.4 m) high must be additionally restrained with anchors. Interior stone anchoring systems must be compatible with the stone and substrate. Stone facing may be installed on gypsum board construction, masonry, or concrete walls. Butt joints are not recommended due to potential spalling (surface chipping or scaling) if movement occurs in the structure. Contributors: Mark Forma, Leo Daly Company, Washington, DC. George M. Whiteside III, AIA, and James D. Lloyd, Kennett Square, Pennsylvania. Alexander Keyes and Darrel Downing, Rippeteau Architects, PC, Washington, DC. TYPICAL CORNER DETAILS 7.325 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 181 INTERIOR F INISHES METAL WALL FINISHES TYPES OF METALS STAINLESS STEEL Stainless steel is an iron alloy that is inherently corrosion resistant because of the addition of chromium. Stainless steels contain at least 11.5% chromium. Nickel or molybdenum is added when maximum corrosion resistance is required. Stainless steel is used in the construction of handrails, floor plates, wall panels, hardware, fasteners, and anchors. Decorative shapes and statuary can be cast in stainless steel. It is popular for use in commercial interiors as column covers and railings, hardware, wall panels, and numerous other products. Its durability, finish retention, and other properties also make it useful for equipment used in food preparation and other commercial equipment, furniture, accessories, and finedining utensils. ALUMINUM Unlike the ores of gold and silver, aluminum ore is not found free in nature. It is always chemically combined with other elements and must therefore be extracted. The majority of the aluminum used today in the United States comes from recycled sources. Aluminum is soft and flexible, allowing it to be easily fabricated. It is light in weight yet remarkably strong. Aluminum is an excellent thermal and electrical conductor; electrical wiring is often made of aluminum. Aluminum is used for door frames and hardware, interior window frames, horizontal louver blind slats, and contemporary furniture. FINISHES Because it is inherently corrosion resistant, aluminum often requires no special finish. A protective oxide film forms rapidly and naturally on the surface when exposed to air. Finishes are frequently applied to aluminum for decorative purposes. Because aluminum’s natural oxide film does not always provide a good bonding surface for coatings, the surface is converted to one with improved adhesion if a coating is desired. Conversion coatings are generally used to prepare the metal for painting but can also be used as final finishes. COPPER Copper is readily available, easily fabricated, and corrosion resistant under a wide range of conditions. Good thermal and electrical conductivity, corrosion resistance, and easy forming and joining all make copper and its alloys useful in construction. Copper is not affected by alkaline chemicals and so is often used where metalto-masonry contact is required. In interior applications, the greatest use of copper is in electrical wiring; it has the second highest conductivity of any material (silver is only slightly higher). Copper is also popular for use in plumbing supply pipes and fittings. Copper can be made harder and stronger by adding small amounts of tin. INTE R I O R CO N ST RU CT I O N 181 BRONZE AND BRASS FINISHES FOR METALS Bronze was originally a copper-tin alloy, but the term today is used to identify other alloys with a bronze color, including aluminum bronzes, silicon bronzes, and leaded phosphor bronzes. Phosphor bronze is a copper-tin-phosphorus alloy; leaded phosphor bronze is composed of copper, lead, tin, and phosphorus. FINISHING PROCESSES AMP 500, Introduction to Metal Finishing, describes the three Brass, a copper-zinc alloy, is commonly used for door hardware and upholstered furniture tacks. Some brass alloys may be called bronzes even though they have little or no tin in them. When a metal is identified as bronze, the alloy cannot contain zinc or nickel; if it does, it is probably brass. Architectural brasses and bronzes are actually all brasses; they are used for doors, windows, door and window frames, railings, trim and grilles, and finish hardware. Muntz metal (also called malleable brass, is a bronze alloy that resembles extruded architectural bronze in color. Muntz metal is available in sheet and strip, and is used in flat surfaces in architectural compositions in connection with extruded architectural bronze. DISSIMILAR METALS When dissimilar metals are connected by an electrolyte, a current, called a galvanic current, flows from one to the other. An electrolyte is any liquid that conducts electricity, for example, water. The current causes one of the metals to deteriorate, and this reaction is called galvanic corrosion. The threat of galvanic corrosion is greatest in exterior applications where materials are exposed to rain or high humidity. However, even in interior applications, galvanic corrosion is of concern. Dissimilar metals in contact with each other, including nails, screws, and bolts, must be coated with or separated by a nonabsorbent, nonconductive material. Metals that are higher on the galvanic scale will corrode when they are electrolytically connected to metals that are lower on the scale. The metal that is more anodic will corrode, or lose material to, the metal that is more cathodic. The farther apart metals are on the scale, the more rapid the corrosion. In addition to the dissimilarity of metals, the amount of metal also plays a part in galvanic corrosion. The less noble (inactive or inert) metal will more likely corrode severely if its surface area is small in comparison with the more noble metal. For example, aluminum (more noble) screws used to fasten a sheet of stainless steel (less noble) to a wall would present a serious corrosion problem in the presence of an electrolyte, but stainless steel screws in an aluminum sheet most likely would perform acceptably. GALVANIC SCALE Metals at the top of the following list—the anodic end—are more noble, and will corrode in the presence of an electrolyte when connected to metals below them on the list. Zinc Aluminum Galvanized steel Cadmium Mild steel, wrought iron Cast iron Stainless steel, Types 304 and 316 (active) Lead-tin solder Lead Brass, bronze Copper Stainless steel, Types 304 and 316 (passive) Almost half of the copper that is used in the United States is recycled rather than newly mined. About half of the recycled copper is postconsumer waste, while the remainder is manufacturing scrap. Prolonged exposure of an untreated copper surface results in a brown and, eventually, green patina. Polishing the surface to remove the oxide film can restore copper’s appearance. The metallic surface can also be preserved by the application of a transparent coating. Source: Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA), Architectural Sheet Metal Manual, 5th ed., Chantilly, Virginia, 1993 . basic finish types—mechanical, chemical, and coating—for various metals. Application environments, service requirements, and aesthetics together determine which metal finish or coating is best to specify. Finishes are usually selected for both appearance and function. Chromium plating on metal bathroom water faucets and handles or baked enamel on sheet metal lighting fixtures, for example, must be attractive as well as functionally protective. MECHANICAL FINISHES Mechanical finishes are accomplished by buffing, grinding, polishing, or otherwise texturing the metal surface for a specific appearance. As-fabricated finishes comprise the texture and surface appearance given to a metal by the fabrication process. Buffed finishes are produced by successive polishing and buffing operations using fine abrasives, lubricants, and soft fabric wheels. Polishing and buffing improve edge and surface finishes and render many types of cast parts more durable, efficient, and safe. Patterned finishes are available in various textures and designs. They are produced by passing an as-fabricated sheet between two matched-design rollers, embossing patterns on both sides of the sheet, or between a smooth roller and a design roller, embossing or coining on one side of the sheet only. Directional textured finishes are produced by making tiny parallel scratches on the metal surface using a belt or wheel and fine abrasive or by hand rubbing with steel wool. Metal treated this way has a smooth, satiny sheen. Peened finishes are achieved by firing a stream of small steel shot at a metal surface at high velocity. The primary aim of shot peening is to increase the fatigue strength of the component; the decorative and slip-resistant finish is a by-product. Other nondirectional textured finishes are produced by blasting metal, under controlled conditions, with silica sand, glass beads, and aluminum oxide. CHEMICAL FINISHES Chemical cleaning cleans the metal surface without affecting it in any other way. This finish is achieved with chlorinated and hydrocarbon solvents and inhibited chemical cleaners or solvents (for aluminum and copper) and pickling, chlorinated, and alkaline solutions (for iron and steel). Etched finishes produce a matte, frosted surface with varying degrees of roughness by treating the metal with an acid (sulfuric and nitric acid) or alkali solution. The bright finish process, not used widely, involves chemical or electrolytic brightening of a metal surface, typically aluminum. Conversion coating is typically categorized as a chemical finish, but because a layer or coating is produced by a chemical reaction, it could be considered a coating as well. Conversion coatings typically prepare the surface of a metal for painting or for receiving another type of finish but are also used to produce a patina or statuary finish. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 182 I N T E R IO R CO NST RU CTION COATINGS Organic coatings on metal can provide protection and serve decorative purposes. Protective coatings include primers or undercoats, pigmented topcoats in hidden areas, and clear finish protective coatings. General categories of organic coatings include paints, varnishes, enamels, lacquers, plastisols (resin and plasticizer mix), organosols (finely divided or colloidal insoluble material suspended in an organic liquid), and powders. Application techniques include dipping and spraying. Electrodeposition is similar to electroplating, except that organic resins are deposited instead of metal. The coating builds up to a uniform thickness without runs or sags and can be deposited into the deeply recessed areas of a complex shape. The process of electrodeposition does not waste paint and emits low levels of volatile organic compounds (VOCs); however, it has limited coating thicknesses, and after the first coat, subsequent coats must be sprayed. Powder coating is perhaps the best known environmentally acceptable painting process. The paints are solventless and therefore safer. Coating powders include epoxies, polyurethanes, acrylics, and polyesters. Powder coatings are either thermoplastic or thermosetting. All three coating types are used extensively on aluminum. Carbon steel and iron require finishes to stabilize the metal surface. Copper alloys are commonly finished with both mechanical and chemical methods. Stainless steel is most frequently finished by mechanical means. DECORATIVE METALS WROUGHT IRON Wrought iron is a form of iron with a relatively soft and malleable fibrous structure. The term, which means “worked” iron, is widely associated with decorative metal. Wrought iron is relatively pure iron with low carbon content. Iron with such low carbon content is scarce today, so most fabricators use steels containing combinations of iron with a higher percentage of carbon for ornamental details. Low-carbon steel or mild steel are the most desirable of these. Steel and iron are the metals most frequently used for decorative metal work. Other popular metals are aluminum (favored for its light weight and rust resistance), polished bronze, brass, and copper. Blacksmiths primarily produce custom work today; a smaller proportion of their work is restoration. Page 182 INTERIOR F INISHES CRIMPED AND WELDED MEMBERS 7.329 STANDARD PERFORATION PATTERNS 7.330 LAMINATED AND PERFORATED METAL SHEETS Finished metals are available in sheet form either as solid metal or laminated to high-pressure laminate (HPL) or phenolic backer sheets. These products are recommended for vertical and lightduty horizontal surfaces; manufacturers recommend protection with glass for other horizontal uses. Finished metal sheets can be bent into radiused corners if not attached to backer sheets. PERFORATED METAL SHEETS Perforated metals were created to fulfill industrial needs such as minimizing the weight of a particular component or controlling the passage of fluids or gases. As an architectural component, perforated metals can be used as control devices or simply as decoration. Perforated metal panels are considered acoustically transparent and may appear to be visually solid, depending on the size of the perforations. Perforated metals retain a great deal of their strength and ventilate well, so they are often employed in furniture and other designs. Common finishes for perforated material include: • Powder coat or wet paint finishes on carbon steel • Brush finished, anodized, or painted finishes on aluminum • Bright, brushed, or electropolished finishes on stainless steel and brass BAR ENDS 7.326 NONSTANDARD PERFORATION PATTERNS 7.331 INTERSECTING MEMBERS 7.327 CORNER CONDITIONS 7.328 Contributors: Edward R. Estes Jr., Norfolk, Virginia. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 183 INTERIOR F INISHES SLOTS 7.332 • • • IPA NUMBER PERFORATIONS OPEN AREA LINE 207 1/8 3/4 (3 19 mm) 41% Side staggered 208 1/8 1 (3 25 mm) 43% Side staggered • • WALL SURFACE COVERINGS SYNTHETIC WALL FINISHES PLASTICS Plastics comprise a widely diverse group of materials; worldwide, there are about 15,000 different plastic formulas available. Like metals, plastics can be alloyed (mixed) with other such materials to improve performance characteristics. Many plastics have long, multisyllable chemical titles, and manufacturers often devise trade names for better marketability. For example, polytetrafluoroethylene is best known by the trade name Teflon. All plastics share three common traits: • With few exceptions (silicone is one), plastics are based on the carbon atom. • Plastics are derived from petrochemicals. • All plastics are polymers, which are giant molecules, composed of up to millions of relatively light, simple molecules. Polymerization, the formation of these giant chains, is basic to the formation of plastics. Polymers are characterized by high molecular weight, outstanding stability, and strength provided by an intermolecular force that prevents easy destruction. COMPONENTS Resin (like polymer, an alternative term used for plastic) is the basic ingredient of plastic. Resins are combined with fillers, stabilizers, plasticizers, pigments, and other components to form plastics. face hardness, and chemical resistance. They are lightweight, colorfast, and do not yellow with age. Acrylics are used for skylight glazing, safety glazing, and paint resins. Polystyrenes: Inexpensive and easy to process, polystyrenes have clarity, hardness, and excellent colorability. They are used for light fixture diffusers, core material for doors, wood-grainpatterned chair parts, and mirror frames. Vinyls: This large group of sturdy, flexible plastics off-gas volatile organic compounds (VOC)s. Polyvinyl butyral (PVB) is used as an interlayer in safety glass. Polyvinyl fluoride is used as a fireretardant textile coating for airplane interiors and as a whiteboard surfacing material. The most common form, polyvinyl chloride (PVC), is used for floor coverings, window blinds, upholstery material, and wallcoverings. Alkyds: Alkyds are oil-modified polyesters. These plastics exhibit moderate heat resistance, a rapid cure cycle, and good mold flow characteristics. Alkyds are used as a paint coating. Melamines: Hardness, clarity, and stain resistance are characteristics of melamines. They are difficult to scratch or cut and do not yellow with age. Most laminating resins for both low- and high-pressure laminates are melamines. Polyesters: Polyester is widely used in textiles for bedding, drapery, and upholstered furniture. It is used for upholstery cushions and insulating material in pillows, comforters, and other furnishings. Polyester is used with glass fibers to form fiberglass. Polyethylene terephthalate (PET) polyester is used to make beverage bottles and Mylar. High-pressure decorative laminates (HPDLs) consist of a sandwich of melamine-impregnated overlay and decorative surface papers, over phenolic resin–impregnated papers. These layers are pressed under temperatures exceeding 265°F and high pressure. Unlike thermoset decorative laminates, sheets of HPDLs are adhered to the surface of substrates, such as particleboard, which can then be trimmed and edge banded. The four most common types of HPDL sheets are: Plastics are commonly categorized as either thermoplastic or thermosetting materials. Vertical-type plastic laminates designed for use on vertical surfaces include: • Thermoplastics become soft when heated and can be remolded repeatedly without affecting the properties of the plastic. Thermoplastics harden when cooled and require the addition of plasticizers to increase their flexibility. • Thermoset plastics are permanently hardened after undergoing an irreversible chemical change during processing. Once they are set, they cannot be softened and remolded. • Fire-rated laminates with a fire-retardant-treated kraft phenolic core, available in 4 by 8 ft (1.2 by 2.4 m) and 4 by 10 ft (1.2 by 3 m) sheets with either a matte or a gloss finish. They are used for interior fire-rated doors, wainscoting, wall panels and dividers, as well as cladding for furniture, cabinetry, and fixtures in airports, hospitals, office buildings, and schools. • High-wear laminates with enhanced abrasion and scuff resistance are available in 3, 4, and 5 ft (0.9, 1.2, and 1.5 m) widths and 8, 10, and 12 ft (2.4, 3, and 3.7 m) heights with a matte finish. Highwear laminates are used for wainscoting, wall panels, and cladding for checkout counters and fixtures in restaurants, fastfood establishments, and banks. • Acrylics: These have the clarity of glass, good weatherability, surContributor: McKey Perforating Company, New Berlin, Wisconsin. HIGH-PRESSURE DECORATIVE LAMINATE 7.334 with melamine resin and then applying it to a substrate (usually particleboard) under low pressure and low heat. The substrate is cut to the required size and shape, and the thermoset decorative laminate is applied, effectively sealing in the substrate. Polyesterimpregnated paper is also used on thermoset decorative laminates. These panels are often used as interior panels and shelves in casework. They are not as durable as high-pressure decorative laminates, but they are far less expensive. • Fillers are added to impart a certain characteristic property, such as durability or heat resistance. Some fillers, called extenders, may be added to decrease the amount of relatively expensive plastic required and to increase the mass of the product. • Stabilizers lend protection against degradation of the plastic resulting from exposure to environmental conditions such as ultraviolet rays and even oxygen. • Plasticizers are mixed with the resin to increase flexibility, resiliency, and impact resistance. The addition of plasticizers lends the required flexibility to sheet vinyl so that it can be rolled without cracking. Synthetic materials used for covering and finishing interior wall surfaces include: LOW-PRESSURE LAMINATE 7.333 PLASTIC LAMINATES Thermoset decorative laminates, sometimes referred to as lowpressure laminates, are made by impregnating laminating paper • HGS: Used for most horizontal surfaces, for example, countertops, this type can be bent to a radius of approximately 6 in. (152 mm). • CLS: Manufactured as a thin sheet, CLS is used for vertical applications, typically inside casework, where it will not be required to withstand heavy wear. CLS should not be used as a balancing/backer sheet for countertops. • BKL: These economical, nondecorative sheets are used on the side of the substrate hidden from view to prevent warping as a result of changes in temperature or humidity. • HGP: HGP is used for tightly radiused curves, for example, at the edge of a formed countertop. TYPES INTE R I O R CO N ST RU CT I O N 183 DECORATIVE WALL SYSTEMS MODULAR WALL TILES Decorative wall systems consisting of modular, interchangeable tiles are designed to extend in any direction and can be custom sized to a given space. The flat tiles with curved outlines are positioned within grooved extrusions, either in a continuous line or in alternating convex and concave rows. The easy-to-change tiles create a woven or wavelike three-dimensional surface that hides imperfections or unevenness in the wall on which they are mounted, eliminating the need for surface preparation. The extruded aluminum frames in which the tiles are placed are lightweight and easy to install on existing walls, or on a wood stud framework covered with medium-density fiberboard (MDF) or similar material. They can also be installed flush with surrounding walls and ceilings, or in recesses. Light sources can be installed in recessed mountings behind tiles, or between the aluminum extrusions. The air spaces created by the curving surface absorb sound and reduce acoustical reverberation within the room. Tiles are available in translucent resins and with finishes including wood veneer, plastic laminates and polypropylenes, printed PETG polyethylene terephthalate, a form of PET, and printed, anodized, or powder-coated metals. SCULPTURAL WALL PANELS Sculptural wall panels for interior wall finishes are available in at least two types: • Sculptural mineral composite (also called cast rock) panels with low relief designs • Carved relief panels with recessed grooved designs 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 184 184 I N T E R IO R CO NST RU CTION SCULPTURAL MINERAL COMPOSITE PANELS Sculptural mineral composite panels create a low relief surface that generates a texture of shadows and highlights. The 32 by 32 in. (813 by 813 mm) panels are assembled with steel-reinforced interlocking joints into a visually seamless surface. Made of cementitious mineral composites, the panels are extremely hard and dense, yet flexible. They are fire resistant, do not emit VOCs, and are relatively lightweight, weighing between 1.5 and 2.5 lb (0.7 and 1.1 kg) per sq ft (0.09 sq m). Repair methods are similar to those for gypsum wallboard, without the face paper. INTERIOR F INISHES DEFINITIONS OF SIX WALLCOVERING CATEGORIES BASED ON PERFORMANCE 7.337 CATEGORY USE For decorative purposes Wallcoverings are not tested. Wallpaper and other primarily residential wallcoverings fall into this category. II Decorative with medium serviceability Primarily decorative but more washable and colorfast than Category I wallcoverings In addition to the testing required for minimum washability and colorfastness, wallcoverings are tested for maximum flame spread and smoke development. Primarily for residential use. III Decorative with high serviceability For medium use, where abrasion resistance, stain resistance, scrubbing ability, and increased colorfastness are more necessary than for Category II wallcoverings In addition to the testing required for Category II wallcoverings, wallcoverings are tested for minimum scrubbing ability, stain resistance, and crocking resistance. They meet more stringent requirements. Primarily for residential use. IV Type I commercial serviceability For use where higher abrasion resistance, stain resistance, and scrubbing ability are necessary in heavy consumer and light commercial use In addition to the testing required for Category III wallcoverings, wallcoverings are tested for maximum shrinkage and minimum abrasion resistance, breaking strength, tear resistance, blocking resistance, coating adhesion, cold-cracking resistance, and heat-aging resistance. All test methods listed in the standard apply to Category III wallcoverings, but the wallcoverings meet more stringent requirements for colorfastness and scrubbing ability than Category III wallcoverings. Appropriate for private offices, hotel rooms, and areas not subject to unusual abrasion or heavy traffic. V Type II commercial serviceability For use where better wearing qualities are required and exposure to wear is greater than normal Tested according to more stringent requirements for scrubbing ability, abrasion resistance, stain resistance, tear resistance, and coating adhesion than Category IV wallcoverings. Appropriate for public areas such as lounges, dining rooms, public corridors, and classrooms. VI Type III commercial serviceability For use in heavy-traffic areas Category VI wallcoverings are tested for the highest scrubbing ability, abrasion resistance, breaking strength, tear resistance, coating adhesion, and maximum shrinkage. Category VI, Type III wallcoverings are commonly used in high-traffic service corridors where carts may bump into the walls. CARVED RELIEF PANELS Carved relief panels have designs created by recessed grooves in wood. One available type is then covered with formed laminate for a very durable white or colored surface. Another is made of reclaimed wood from Forest Stewardship Council (FSC) certified sources. Fire-retardant and water-resistant cores are also available. The panels can be sawn, nailed, screwed, glued, and cleat mounted. WALLCOVERINGS Wallcoverings offer improved durability over paint finishes while providing texture and pattern to the wall surface. Wallcovering types include textiles, vinyl, wallpapers, fiberglass, and wood veneer. The use of vinyl wallcoverings is declining due to environmental and health concerns, and manufacturers are seeking more environmentally acceptable alternatives, including fibrous polyester cellulose materials. GUIDELINES FOR CALCULATING ONE LINEAL YARD OF WALLCOVERING 7.335 WALLCOVERING WIDTH SURFACE TO BE COVERED 54 (1,370 mm) 13 sq ft (1.2 sq m) 36 (910 mm) 9 sq ft (0.8 sq m) COMMENTS Decorative only Sculptural mineral composite wall panels are designed for interior use only. They are not a substitute for gypsum wallboard in code-required fire-rated walls, where they may be installed over the wallboard. Surfaces are finished with a manufacturer-approved low-VOC wall sealer and then painted with interior paint, preferably applied with an airless sprayer. A final coat of flat paint helps to hide seams. White and light colors increase shadow contrast. DESCRIPTION I TEXTILE WALLCOVERINGS Not all textiles are suitable for use as wallcoverings. Textile wallcoverings are not appropriate in applications where wear resistance is a concern. Some of the fabrics that are used include polyester, linen, wool and wool blends, damask, and velvet. Textiles must be back-coated to be installed as wallcovering. The backing provides a barrier to prevent adhesives from bleeding through and ruining the finish face of the fabric. Backings also provide the dimensional stability required for a textile to withstand the stretching and smoothing operations of wallcovering installation. Two common types of back-coating treatments are paper backing and acrylic latex backing. New products are being developed to replace the use of latex backing in most commercial projects. • Paper backing involves laminating paper to the reverse side of the textile. This process stiffens the textile for easier installation. The textile assumes properties similar to those of wallpaper. • Acrylic latex coating involves stretching the textile in a frame and applying a latex compound. The textile retains some of its inherent flexibility and is much less dimensionally stable than paper-backed textiles. Latex backings can improve ravel resist- WALLCOVERING DURABILITY CLASSIFICATIONS 7.336 PROPERTY CATEGORY II: DECORATIVE WITH MEDIUM SERVICEABILITY CATEGORY III: DECORATIVE WITH HIGH SERVICEABILITY CATEGORY IV: TYPE I COMMERCIAL SERVICEABILITY CATEGORY V: TYPE II COMMERCIAL SERVICEABILITY CATEGORY VI: TYPE III COMMERCIAL SERVICEABILITY Minimum colorfastness 23 hr 46 hr 200 hr 200 hr 200 hr Minimum washability 100 cycles 100 cycles 100 cycles 100 cycles 100 cycles Minimum scrubbing ability — 50 cycles 200 cycles 300 cycles 500 cycles Minimum abrasion resistance — — 200 cycles (220 grit) 300 cycles (220 grit) 1,000 cycles (220 grit) Minimum breaking strength: MD (machine direction) CMD (cross machine direction) — — — — 40 lb (178 N) 30 lb (133 N) 50 lb (222 N) 55 lb (245 N) 100 lb (445 N) 95 lb (423 N) Minimum crocking resistance — Good Good Good Good Minimum stain resistance — Reagents 1 to 9 Reagents 1 to 9 Reagents 1 to 12 Reagents 1 to 12 Minimum tear resistance — — 12 25 50 Maximum blocking resistance — — 2 2 2 Minimum coating adhesion — — 2 lb/in. (17.8 N/5 cm) 3 lb/in. (26.7 N/5 cm) 3 lb/in. (26.7 N/5 cm) Minimum cold cracking — — No change No change No change Minimum heat aging resistance — — Pass Pass Pass Maximum flame spread 25 25 25 25 25 Maximum smoke developed 50 50 50 50 50 Maximum shrinkage: MD (machine direction) CMD (cross machine direction) — — — — 2 1 2 1 2 1.5 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 185 INTERIOR F INISHES ance and seam slippage. The use of latex-coated textile wallcoverings may increase installation costs. Often, this wallcovering’s lack of rigidity requires that the adhesive be applied to the wall, rather than to the back of the wallcovering. This process is more labor intensive and requires a higher degree of skill. STEINER TUNNEL TEST 7.340 CODE REQUIREMENTS In the language of the codes, textiles include materials having woven or nonwoven, napped, tufted, looped, or a similar surface. Textile wallcoverings must meet either of the following conditions: • They must have a Class A flame spread index and be protected by automatic sprinklers. When used to limit the spread of fire, sprinklers in this instance only have to be installed where the textile wallcoverings are used. • They must meet the criteria of NFPA 265, Standard Methods of Fire Tests for Evaluating Room Fire Growth Contribution of Textile Wall Coverings on Full Height Panels and Walls, when tested in the manner intended for use, using the product mounting system, including adhesive. NFPA 265 is commonly referred to as the Room Corner Test, and was developed exclusively for textile wallcoverings. It was designed to simulate more realistic circumstances than the Steiner Tunnel Test, which mounts materials on the ceiling of the test chamber. The wall substrate, adhesive, and textile wallcovering to be used are installed in a near full-scale room and tested. This test determines the contribution to a room fire made by a wall finished with a textile wallcovering. FABRIC ATTACHED TO WALL FLAMMABILITY REQUIREMENTS 7.338 APPLICATION FLAMMABILITY TEST Stretched-fabric wall systems Steiner Tunnel Test Freestanding furniture panels Steiner Tunnel Test Tackboards Steiner Tunnel Test Acoustical panels Steiner Tunnel Test Wallcoverings Room Corner Test ROOM CORNER TEST 7.339 WOOD VENEER WALLCOVERINGS Wood veneer wallcovering is made by bonding veneer slices, about 1/64 in. (0.39 mm) thick, to a woven backing material. The resulting wallcovering is thin enough to be pliable along the grain lines but too thick to be flexible in the horizontal direction (perpendicular to the wood grain). The inherent flexibility of wood veneer wallcovering allows easy installation around columns and other curved surfaces. Wall surface imperfections tend to telegraph through the thin veneer. In areas where the substrate cannot be prepared to a smooth, level surface, veneered plywood panels are a better choice. Buckling and warpage caused by moisture can be a significant problem for this kind of wallcovering. It is not recommended that wood veneer wallcovering be applied to the interior surface of an exterior wall unless the finish face of the wall is furred out and dampproofed. VINYL WALLCOVERINGS Vinyl products are durable and flexible, and have been a mainstay of commercial interior wallcoverings for years. However, they are petroleum based, emit VOCs, are not generally recyclable, and release toxic gases if burned. Because it is impermeable to water, vinyl wallcovering can harbor mold and mildew under its surface. Some manufacturers offer water-permeable vinyl wallcoverings that allow walls to breathe. Environmentally conscious architects and designers are advised to seek alternatives to vinyl wallcoverings. Wood veneer wallcoverings are available prefinished or unfinished. Unfinished veneers must be stained and finished after they are installed. Some finishes, for example, penetrating oils, can have an adverse effect on the wallcovering adhesive. Coatings applied to the surface of installed wood veneer should be approved by the wallcovering manufacturer. The installation of wood veneer wallcovering is similar to the installation of other types of wallcovering; however, the sheets must be butted together and cannot be overlapped and trimmed. WALLPAPERS OTHER TYPES OF WALLCOVERINGS Manufacturers are developing Type II commercial wallcoverings that have the durability and ease of maintenance of vinyl wallcoverings, but which are free of chlorine and PVCs. These products are typically nonrecyclable and do not contain recycled materials; unlike vinyl, however, they can be incinerated or landfilled. Microvented products are available for use in environments where mold and mildew growth are problems. Polyester and co-polyester microfilament fiber wallcoverings printed with water-based inks and with low VOC emissions are available from some manufacturers. They are advertised as 100% recyclable, including construction waste and postuse material. Fiberglass wallcovering is composed of fiberglass yarns adhered together. Fiberglass wallcovering is inherently flame resistant and is suitable for use in reinforcing fragile or deteriorating wall surfaces. It is permeable, making it intrinsically mold and mildew resistant. Fiberglass wallcoverings must be painted after installation. This wallcovering type provides a textured pattern only, not a color. Typically, a latex paint is selected to maintain the breathability of the wall. INSTALLING WALLCOVERINGS It is important to determine the manner in which the wallcovering will be installed. Consult the manufacturer and distributor for information. Textured wallcoverings may show up as distinct panels when reversed. If problems are encountered, three test strips should be installed in a nonreversed pattern and their appearance evaluated. INSTALLING WALLCOVERINGS 7.341 Contributors: David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Bob Pielow, Pielow Fair Associates, Seattle, Washington. INTE R I O R CO N ST RU CT I O N 185 Wallpapers are composed of a paper face and a paper backing. They are not commonly used for commercial applications because of their fragility and poor wear resistance. However, the scratch, stain, and abrasion resistance of wallpaper can be improved by requiring that the finish face be coated with a clear vinyl film. Vinyl-coated papers, consisting of a paper substrate coated with acrylic/vinyl or solid PVC with a total thickness of 2 to 5 mils (0.05 to 0.13 mm), are scrubbable and peelable or strippable. They are suitable for use in residential kitchens, bathrooms, and laundry rooms, but not for commercial applications. Custom wallpapers begin as sketches, references, or concepts. The wallpaper designer may work with graphics or photographs and develop repeats and layouts, leading to strike-offs and final products. Hand-printed wallpapers are block printed by hand or silk screened. Block printing is usually done in two colors with linoleum blocks hand cut from drawings. The natural irregularities of hand printing result in subtle variations. Hand silk screening is somewhat less time consuming but still retains a soft, handmade appearance. Hand-screened prints are available on handcrafted hemp, linen, jute, and on woven and recycled papers. A variety of natural-fiber materials are used for paper-backed wallcoverings, some of which are Class A and E-84 rated. Widths are pretrimmed or untrimmed and range from 36 to 45 in. (914 to 1,118 mm) for pretrimmed, and 53 or 54 in. (1,346 or 1,372 mm) for untrimmed. Materials include grass cloth, rush cloth, raffia, hemp, bamboo, kenaf reed, and abaca. Other materials used include cork and handcrafted, rice, or woven paper. Paper-backed silk wallcov- 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 186 I N T E R IO R CO NST RU CTION erings are available, some with metallic or abaca materials included. More exotic options include embroidered cotton, wood veneer, mother-of-pearl, mica, and glass beads. Gold and silver leaf, as well as faux gold leaf, are available backed with colored papers for use as wallcoverings. Page 186 INTERIOR F INISHES WALLCOVERING PATTERN REPEAT 7.343 Historic wallpapers from the 17th to 20th centuries are produced from original documents or reproductions, often for use in historic restoration projects. Original antique wallpapers are available as well. HANDMADE WALLCOVERINGS 7.342 WALLCOVERING RANDOM MATCH 7.344 WALLCOVERING DROP MATCH 7.345 ROLL SIZE AND SEAMS Typically, residential wallcoverings range in width from 20-1⁄2 to 28 in. (521 to 711 mm). A single roll yields 27 to 30 sq ft (2.5 to 2.8 sq m). Single rolls are packaged and sold in double-roll quantities. Double rolls have 56 to 58 sq ft (5.2 to 5.4 sq m) and are approximately 11 yards (10 m) long. Pattern and seam placement may be critical. Large, complicated, dominant pattern repeats may need careful placement to establish a starting point. Dominant pattern repeats are often centered at eye level, with the pattern matching at 72 in. (1,830 mm) above the finish floor. The three types of pattern matching include the following: • Random match is the least wasteful type of pattern matching. Panels do not align horizontally. • Drop match patterns do not repeat at the same distance from the ceiling line, creating the greatest potential for waste. Patterns that match every third or fourth panel are referred to as multiple drop matches. • Straight match patterns match with the continuation of the pattern on the next panel. The pattern repeats at the same distance from the ceiling line. Contributors: Carl Henschel, Rhode Island School of Design, Providence, Rhode Island. MASTERSPEC®, published by ARCOM, Salt Lake City, Utah. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 187 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 187 used to achieve a soft, upholstered appearance. • Fiberglass blanket is a thick sheet of loosely intertwined fiberglass strands. It is often used where acoustical absorption is a concern. • Fiberglass board ranges in density from acoustically absorptive panels with fair tackability to acoustically reflective panels. • Mineral fiberboard is a composite of inorganic mineral fibers. Unlike pressed, recycled paper products, mineral fiberboard is dimensionally stable. It is more durable and impact resistant than fiberglass board and can be microperforated where an absorptive acoustical surface is required. • Particleboard is a nailable core material. Plywood can warp and is not recommended for use as a core material, but can be used as nailable strips in panels of other core materials. • Pressed recycled paper products can double as tackboards. They are available uncovered for painting, or with burlap surfaces. • Wood fiberboards are durable and paintable, and have good acoustic properties if properly mounted. They can also be used on ceilings. WALLCOVERING STRAIGHT MATCH 7.346 PANEL INSTALLATION Common acoustical panel installation methods include: UPHOLSTERED WALL SYSTEMS Upholstered wall systems, also referred to as stretched-fabric wall systems, combine the luxuriousness of textile wallcoverings and the practicality of a tackable or acoustically absorptive wall surface. Upholstered wall systems are site-constructed coverings that stretch fabric taut over a frame and infill material. They can also be used in ceiling installations. FRAMING METHODS The framing material is typically either a plastic extrusion or a wood frame. An extrusion system holds the fabric in place by friction or with concealed fasteners, sometimes aided by an adhesive. Concealed fasteners are used with a wood frame system. CORE MATERIALS 7.347 MATERIAL APPLICATION Acoustical batting (polyester or fiberglass) Soft, upholstered appearance; acoustically absorptive Plywood Nailable; acoustically reflective surface Mineral fiberboard Tackable; acoustically absorptive Fiberglass board Durable; impact resistant UPHOLSTERED WALL SYSTEMS 7.348 NOTES 7.348 a. No size limitation. b. No size limitation. Limited in size to core and frame material and ability to enter building, for example, door opening and elevator cab sizes. Contributors: Tanya Nachia, Rhode Island School of Design, Providence, Rhode Island. Robin Staack, Boston Architectural Center, Boston, Massachusetts. MASTERSPEC®, published by ARCOM, Salt Lake City, Utah. Merve Yoneyman, Rhode Island School of Design, Providence, Rhode Island. FABRIC SELECTION Upholstered wall systems require the selection of a highly stable fabric. Upholstery-weight fabrics are good choices. The fabric should be hydrophobic (does not readily absorb moisture); otherwise, seasonal changes in relative humidity may cause sagging and rippling. A fabric that contains more than 30% rayon or viscose or 10% nylon fibers is typically not suitable for use in upholstered wall systems. If the wall system is to perform as a tackable or nailable surface, the selected fabric should be self-healing and snag resistant. For a seamless appearance, fabrics up to 120 in. (3,050 mm) wide can be specified and installed horizontally (sometimes referred to as railroading). ACOUSTICAL WALL PANELS Properly mounted acoustical wall panels can significantly improve the acoustical absorption of a room. Placement, both horizontally and vertically, is important in maximizing their effect. Thin textiles applied directly to the wall surface have virtually no affect on acoustic absorption. PANEL CORE MATERIALS Core materials can be combined in a panel to achieve the required performance. For example, a nailable surface can be achieved by inserting a plywood nailing strip into a panel with a fiberglass board core material. Common panel core materials include the following: • Polyester batting consists of fibers loosely intertwined and is • Z-clips are the preferred method for temporary or movable panels. Z-clip panels require a reveal between the top of panel and the ceiling so that the panels can be lifted and lowered into place. The lower clip is fastened to the wall; the upper clip is fastened to the panel. • Hook-and-loop tape: Mechanical fasteners should be used to secure the hook tape to the wall. This method is often used with adhesive to hold panels in place while the adhesive is setting. Newer heavy-duty products are available. • Impaling clips are fastened to the wall; the barbed projections of impaling clips are pressed into the panel back. This installation method is not commonly used because of its inability to support substantial weight. It is also more prone to vandalism. • Adhesive: Adhering an acoustical panel to a wall or ceiling with adhesive is a permanent mounting method. Panels cannot be removed without damaging them and the substrate. PANEL TEXTILE SELECTION CONSIDERATIONS 7.349 FABRIC ATTRIBUTE Color SELECTION CONSIDERATION Light-colored textiles show soil more readily than dark-colored textiles. Opacity Core material should not read through the textile face. Resilience Nonbacked textiles ease stretching and do not impair acoustical transparency. Self-healing Tackable and nailable panel textiles must be snag resistant. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM 188 I N T E R IO R CO NST RU CTION Z-CLIP ATTACHMENT 7.350 Page 188 INTERIOR F INISHES ACOUSTICAL WALL PANEL SECTION DETAIL 7.351 PAINTS AND COATINGS INTERIOR WALL PAINTING COATING SELECTION CRITERIA Paint has three basic functions: to decorate, to protect, or to modify the performance of the substrate to which it is applied. Paint ingredients, types, and applications all affect a coating’s performance. The following criteria are considerations for selecting the appropriate coating for a given application: • • • • • • • • • • • • Abrasion resistance Adhesion Impact resistance Flexural qualities Resistance to a given medium (e.g., chemicals) Resistance to sunlight Temperature resistance Drying time (installation criteria) Appearance Wetting time Emissive requirements (reflection and absorption) Electrical insulation INGREDIENTS There are four categories of paint ingredients: pigment, thinner, resin, and additives. • Pigment provides color, hiding, and bulk. • Thinner affects consistency and drying time and carries the pigment and resin to the substrate. • Resin binds the pigment particles together and affects adhesion, durability, and the level of protection of the paint film. • Additives enhance the coating’s performance with specific desirable characteristics. Source: StretchWall Installations, Inc., Long Island City, New York. The term paint solids refers to the resin. A higher solids content provides a thick, durable, opaque coating. The solids content of paint can be specified by weight or by volume; volume of solids is the better indicator of performance. Latex paints range from 25 to 40% volume of solids. Alkyd and oil-based paints can exceed 50% volume. PAINT FORMULATION 7.353 Pigments + Resin = Solids + Liquid = Solids Paint Fused solids + Liquid = Final coating SHEEN Source: StretchWall Installations, Inc., Long Island City, New York. ACOUSTICAL WALL PANEL PLAN DETAIL 7.352 The presence of pigment reduces the gloss of the cured paint film. By increasing the amount and dimension of the pigment particles in relationship to the amount of resin, the resin’s level of gloss or the texture of the paint is reduced. The texture of cured paint is called sheen. Pigment color and sheen determine the light reflectivity of a painted surface, which affects the perception of the color. The more pigment that is present relative to the resin, the rougher textured, less reflective, and flatter is the paint’s appearance. A glossy surface is achieved by a larger volume of resin that encases the pigment. PAINT SHEENS 7.354 SHEEN Source: StretchWall Installations, Inc., Long Island City, New York. REFLECTING ANGLES High gloss >65° Semigloss 30° to 65° Satin 15° to 35° Eggshell 5° to 25° Flat >15° 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:32 AM Page 189 INTERIOR F INISHES PAINT AND COATING TYPES ALKYD PAINT The solvent-thinned resin in alkyd paint is made from synthetic oils. Alkyd resins are oil-modified polyesters made primarily from alcohol and acid. They are the most common paint resin. Alkyd paints are faster drying, harder, and more durable, and have better color retention properties than oil-based paints. They are easy to apply, are washable, and have less odor than other paints using solvent thinners. LATEX PAINT Most water-based paints are referred to as latex paint. Over 80% of architectural coatings sold today are latex paints. They have less impact on the environment than oil-based and alkyd paints and lower volatile organic compound (VOC) emission levels. Leftover paints can be mixed and reused. Latex paints have very little odor and a fast drying time. Their water-based thinner makes latex paints easy to apply, clean up, and discard. Latex paints are porous; when applied, a latex coating retains microscopic openings that allow it to breathe. LOW-ODOR AND LOW-VOC PAINTS During the curing process, solvent-thinned coatings (including latex and most waterborne coatings) release VOCs into the atmosphere. VOCs are measured in grams of organic solvent per liter of paint or lb/gal (g/L). The presence of odor in wet paint is related to the solvents used; water-based paints are less odorous than oil-based and alkyd paints. VOCs are often detectable by their odor, so low odor and low VOC content are sometimes linked. Low-odor, low-VOC paints allow painting contractors to work in occupied spaces without disturbing or potentially harming occupants. Low-odor and low-VOC paints are comparable to other latex paints in performance, although washability and stain removal may be slightly less. They are primarily used on interior walls; some are appropriate for trims as well. Wallboard as well as wood, hardboard, medium-density fiberboard (MDF), and molded composite trims should be primed first. The colorants added to both oil-based and water-based paints can also contain VOCs. In light-colored paints, only a little colorant is used, but this can become more of a problem with heavily tinted paints, especially where used in large quantities. OIL-BASED PAINT Oil-based paint requires less surface preparation than latex paint and adheres better to surfaces that are dirty, shiny, or heavily weathered. It is more resistant to abrasion. The solvent-thinned resin in oil-based paint is made from organic solvents, usually mineral spirits made from petrochemicals. Binders can be synthetic resins derived from petroleum (alkyds, polyurethanes, and silicones) or natural oils, such as linseed (from flax seed), soya bean (from soybeans), tung (from china wood tree fruit), safflower, and cottonseed oils. The environmental impact of oil-based paints is much greater than that of latex paints, and disposal is more problematic. PRIMERS Primers make a surface more paintable by providing improved adhesion for coatings. Primers are selected in relation to the characteristics of the chosen topcoat. Primers serve the following functions: • Concealing the substrate surface so that the existing coating color does not read through the paint • Providing a barrier to prevent moisture from destroying the paint bond • Binding the substrate surface with the topcoat • Limiting the paint absorption of a porous substrate, such as a skim coat of plaster • Reconditioning old paint to receive future paint coatings • Acting as a rust inhibitor COMMON PAINT ADDITIVES 7.355 ADDITIVE PURPOSE CATALYZED EPOXY PAINT Catalyzed epoxy coatings resist chemicals, solvents, stains, physical abrasion, traffic, and cleaning materials. They have good adhesion and color retention. Catalyzed epoxies come in two parts, resin and catalyst. They have limited pot life, hence are required to be mixed just prior to use. When applied to a substrate, a chemical reaction occurs that causes a dense hard film to form, similar to baked enamel. Adequate ventilation must be provided during and after application. Catalyzed epoxy paints are used for high-traffic commercial and institutional interiors and exteriors. Typical uses include schools, stadiums, prisons, hospitals, and nursing homes. Three types of catalyzed epoxies are commonly used in commercial interiors: • Polyester epoxies produce a tough glossy surface. • Polyamide epoxies provide a flexible but durable film. • Urethane epoxies are the most versatile of the epoxy coatings. EPOXY ESTER PAINT Epoxy esters are similar to catalyzed epoxy but have no pot life restrictions and are packaged like conventional paint. The paint film occurs due to oxidation rather than a chemical reaction triggered by a catalyst. Epoxy esters are less durable than catalyzed epoxies. FLAME-RETARDANT (INTUMESCENT) AND FIRE-RESISTANT PAINTS Flame-retardant paints slow the rate at which fire spreads by delaying the ignition of the surface that has been coated. They are used on combustible materials such as wood to achieve the required flame spread ratings. These paints delay, but do not prevent, a fire from spreading. INTE R I O R CO N ST RU CT I O N 189 Flame-retardant paint is a foamlike material that is made with either a water-based thinner or a solvent-based thinner. Flameretardant paints are intumescent and protect the substrate from burning by swelling to form a charred layer of blisters when exposed to extremely high heat. Fire-resistant paints resist the spread of fire by not contributing to the flame. They are less effective at controlling the spread of fire than intumescent coatings. MULTICOLOR COATINGS Multicolor coatings are durable and scratch resistant. They add a three-dimensional quality to a surface, similar to hand-sponge techniques. These coatings can be used on substrates as varied as concrete block, gypsum wallboard, ceramic tile, glazed block, textured surfaces such as stucco, and metal. They are not recommended for fabric surfaces. Multicolored coatings are suitable for areas of high traffic, harsh environments, and repeated cleanings, such as hospitality, healthcare, educational, office, and manufacturing facilities. Multicolor coatings can be solvent thinned or water thinned: • Solvent-thinned multicolor coatings are composed of tiny bubbles of different sizes and colors suspended in a nonpigmented solution. The separated beads of pigment remain separate until they are spray applied. They burst upon impact with the surface. Solvent-based coatings have higher VOC emissions and more odor than water-based coatings, and dry considerably more slowly. • Water-thinned multicolor coatings have been improved over the years, and are available with good particle size ranges and durability. However, they may be less stain resistant than solventbased products. Acrylic multicolor coatings have extremely low VOC levels, are breathable, and resist mold and mildew growth on the paint film. These durable, abrasion-resistant, and easily cleaned coatings are suitable for interior walls, columns, and ceilings. They are not to be used on floors, exteriors, and where water frequently collects. STAINS Stains made from dyes dissolved in either drying oil or water are used as translucent or transparent coatings for wood. Pigmented stains are opaque. Gel stain is a gelled form of oil-based stain suitable for use on wood, plywood, veneer, fiberglass, metal, and molded fiberboard. VOCs emitted by stains are primarily from the solvent, which makes up most of the product, rather than from the relatively small amount of colorant. Oil-based stains clean up with mineral oil, whereas water-based stains clean up with soap and water. Oil-based stains use drying oil made from various plants, including tung oil. The oil dries by absorbing oxygen from the surface, and the air creates a tough elastic film that protects the wood. Wood surfaces can be filled before staining for surface porosity and smoothness, but fillers may cause stains to be absorbed unevenly. Stain may be applied with a brush, spray, roller, or rag pad. Oilbased wood stains are suitable for use on floors, doors, woodwork, furniture, and cabinetry. Antiskinning agent Prevents skin from forming in can prior to use Biocide Prevents spoilage resulting from bacterial growth Coalescent Aids in formation of continuous film in latex paint Defoamer Eliminates air from paint or reduces bubbling upon application Drier Accelerates conversion of solvent paints from liquid to solid state Freeze-thaw stabilizer Lowers latex paint freezing point Mildewcide Resists growth of mildew Faux finishes typically comprise layers of paint and/or plaster and are designed to mimic a natural material such as marble, wood veneer, silk, suede, velvet, copper, bronze, silver, or gold, or to lend the effect of an aged stone or plaster. Surfactant Stabilizes mixtures of resins or pigments in solvents or water Special paint finishes also utilize paint and plaster but seek to create an original finish not intending to mimic an existing material. Thickener Increases consistency of paint and prevents separation of pigment in oil- and water-based paints INTUMESCENT PAINT 7.356 DECORATIVE PAINT FINISHES Faux finishes are technically those that imitate natural materials such as wood graining and marbleizing, but the term is often used for any decorative painted finish. A faux finish or special paint finish can provide a means to add color and texture to interior walls and offers a cost-effective alternative to fabric, stone, wood, or other materials when durability is not an issue. The simplest finishes typically consist of a base color, usually an eggshell paint applied over a sanded and sealed wall surface, and a colored glaze applied in a broken pattern such as a rag roll, a sponge, a dragged glaze, or a color wash. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 190 I N T E R IO R CO NST RU CTION More complex variations on these basic techniques involving multiple layers of glazes in various colors result in the classic faux marbre (marble) and faux bois (wood) finishes. Faux stone and antique plaster effects are usually achieved with layers of plaster and glaze. Modern metallic and iridescent paints allow myriad effects, some resembling metals or mother-of-pearl, others existing without reference to natural materials. So-called Venetian plaster is the application of a thin veneer of plaster-like material in layers that can be waxed and burnished to a soft sheen with metal blades. All faux finishes are highly idiosyncratic, and the final effect is in the hands of the individual who applies the material; hence, it is critical to request samples for approval. Trompe l’oeil is French for “fool the eye,” and it describes painted decorative surfaces that use perspective and shadow to create the impression of three-dimensional architectural objects. Grissaille is monochrome trompe l’oeil. Transparent paint layers are finish layers made from a neutral base or glazing liquid. They can be applied in multiple layers, and tend to darken and tint the color of the base coat. Glaze is a tinted transparent coating that softens and varies the base coat. Page 190 INTERIOR F INISHES for testing carpet flammability with a methenamine tablet for carpets larger than 6 ft (1.8 m) in one dimension and greater than 24 sq ft (2.23 sq m) in area offered for sale in the United States. MATERIAL FLOORING RADIANT PANEL TEST Floor coverings are not usually regarded as the primary cause of flame spread during a fire. However, flooring material in corridors has been observed to present problems in full-scale tests and actual building fires. In a fully developed fire, the combination of heat, flame, smoke, and gases emanating from burning rooms surrounding a corridor can make a substantial contribution to flame spread. ASTM E 648, Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source, known as the Flooring Radiant Panel Test, exposes the floor covering sample to radiant heat and igniting flames. This test was designed to simulate more realistic circumstances than the Steiner Tunnel Test, which mounts materials on the ceiling of the test chamber. The Flooring Radiant Panel Test is different from most other flammability test methods because it measures an actual property of the carpet system. It is not based on an arbitrary scale. FLOORING RADIANT PANEL TEST 7.358 Stenciling is used to apply borders or larger repeats (resembling wallpaper) in one or more colors with regular paint or textured paint or plaster. A brocade stencil finish involves a decorative stencil in flat paint applied over a background of broken color in a satin finish. 0.08 Carpet 0.4 (10 mm) thick 0.18 Fiberglass insulation 0.4 (10 mm) thick 0.22 Fiberboard insulation made from recycled newspapers 1/2 (13 mm) thick 1.2 Prime urethane carpet cushion 1/2 (13 mm) thick 2.1 THERMAL CONDUCTIVITY OF FLOORING 7.361 THICKNESS THERMAL CONDUCTIVITY (U-VALUE) Cork 1/8 (3 mm) 0.028 Linoleum 1/8 (3 mm) 0.087 Vinyl 3/16 (5 mm) 0.427 Wood 1/4 (6 mm) 0.199 Marble 5/8 (16 mm) 1.598 FLOORING IMPACT NOISE RATING Floors are subject to impact sound transmission noises such as footfalls, dropped objects, and scraping furniture. Parallel to the development of laboratory sound transmission class (STC) ratings for partition constructions is the development of impact insulation class (IIC) ratings. This is a single-number rating system used to evaluate the effectiveness of floor construction in preventing impact sound transmission to spaces beneath the floor. The current IIC rating method is similar to the STC rating method. FLOOR FINISH CODE REQUIREMENTS Floor finishes regulated by the International Building Code (IBC) include carpet, combustible materials installed in or on floors of Type I or Type II buildings, and flooring in certain exit and exit access areas of particular occupancies. Floors of traditional materials, including wood, vinyl, linoleum, terrazzo, and resilient floor covering, are not regulated. ADA/ABA Accessibility Guidelines contain requirements for accessible flooring. CONTROLLING SOUND FLOOR COVERING FABRIC APPLICATION AND FLAMMABILITY TESTS 7.359 FLOOR COVERING FLAMMABILITY TEST Carpet in corridors Flooring Radiant Panel Test Carpet tile in corridors Flooring Radiant Panel Test Area rugs Methenamine Pill Test THERMAL CONDUCTIVITY Uninsulated floors can be responsible for 10 to 20% of the heat loss in a home. Carpet helps to reduce heating and cooling energy costs where there is a difference in between indoor and outdoor air temperature under the floor. Carpet is recommended to reduce heat loss from timber or elevated slab floors. Carpet fibers are natural insulators with low heat conductance values. In addition, the fine surface pile fibers trap insulating air. Carpet has the best insulation properties of common flooring materials. With fiberboard insulation and pad, it can achieve an R-value of 3.3. Contributors: Faith Baum, AIA, IIDA, Faith Baum Architect, Lexington, Massachusetts. David Ballast, FAIA, Architectural Research Consulting, Denver, Colorado. Bob Pielow, Pielow Fair Associates, Seattle, Washington. Julia Purinton, Medusa, Ipswich, Massachusetts 0.07 Plywood 0.4 (10 mm) thick ACOUSTICAL CONTROL FLOOR DESIGN CONSIDERATIONS METHENAMINE PILL TEST 7.357 R-VALUE Concrete 4 (102 mm) thick Source: Arcobel, Houston, Texas. Subtractive painting techniques involve applying and then removing wet paint with sponges, rags, plastic, or other materials to create visual texture. METHENAMINE PILL TEST ASTM D 2859, Standard Test Method for Ignition Characteristics of Finished Textile Floor Covering Materials, prescribes the standard R-VALUE COMPARISONS 7.360 There are three types of sound that building designers concern themselves with. Impact sound is generated by anything coming in contact with the flooring. Airborne sound comes from anything that creates noise. The third type of sound is resonance, or that portion of impact or airborne sound that reverberates or echoes within the room. Most nonresidential building codes require wall and floor/ceiling assemblies to transmit a reduced level of impact and airborne sound. The codes call for a minimum 50 dB sound reduction and reference STC 50 and IIC 50 as standards. SOUND CONTROL 7.362 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 191 INTERIOR F INISHES FLOORING FINISH APPLICATIONS SHOWER, LOCKER, AND TOILET ROOMS INTE R I O R CO N ST RU CT I O N 191 CONCRETE FLOOR FINISHES 7.363 The shower room should be directly accessible to the drying room and locker room that it serves. When a shower room is designed to serve a swimming pool, the room should be located so that all must pass through showers before reaching the pool deck. TYPE OF TREATMENT Veneer concrete Thin cementitious topping ranging from 3⁄16 to 2 in. (5 to 51 mm); may be colored and stamped. Veneer coatings can be susceptible to chipping. Use a thicker coating in high-traffic areas. Separate wet and dry toilet areas are recommended. Wet toilets should be easily accessible from the shower room. When designed for use with a swimming pool, wet toilets should be located so that users must pass through the shower room after use of toilets. Integral color liquid and dry pigments Provides uniform color throughout; nonfading and weather resistant. Usually available in pastels and earth tones. Color cannot be saturated without compromising the structural integrity of the concrete. Light colors work best if white sand and aggregate are used. Use the same concrete supplier for consistency, and make sure the same batch of concrete is used for the entire load. Batch color at plant if possible. A test slab should be poured and approved prior to starting a job. Acrylic stain (methyl methacrylate copolymer) Mar, scratch, stain, and water resistant. Can be used on vertical surfaces. May be used to restore color to an older structure. Acrylic sealer (as above, except clear) Anti-graffiti; provides a clear protective film, which prevents the penetration of spray paint, etc. Can be used on vertical surfaces. Nonyellowing oxidized acrylic Sealer with a wet look. Used for washed aggregate, ground face block, split-block, or sand-blasted concrete. Stamped concrete Texture is stamped into concrete to mimic patterns of brick, slate, stone, tile, etc. Control and pour joints must be handled very carefully. Plan them to work with the stamped pattern selected. Control joints should be saw cut at least one-third of the slab thickness and should be installed once every 12 to 15 ft (3.6 to 4.5 m). Stamped concrete with colored release agents (synthetic iron oxides for color) Gives additional color and serves as a stamping tool release agent. Can be used in conjunction with integral or dry shake color when imprinting the concrete. Dry-shake color hardeners Powdered cementitious material containing hard aggregates. When in-service conditions require concrete slabs with improved surface hardness, shake-on hardeners may be applied, floated, and troweled into the plastic concrete surface. Lightfast and weather resistant. Not classified as a topping. Hand-broadcasted across the concrete surface and floated into the slab after the bleed water has evaporated. Floors should be of impervious material, such as ceramic or quarry tile, with a carborundum-impregnated surface, and should slope toward the drains. Concrete floors with a nonslip surface, if used, should be treated with a hardener to avoid the penetration of odors and moisture. HARD FLOORING CONCRETE FLOOR SYSTEMS Concrete floor systems consist of the following types: Flat plate: This is the best system for moderate spans because it is the most economical floor system and has the lowest structural thickness. Banded slab: This system has most of the advantages of a flat plate, but permits a longer span in one direction. It can resist greater lateral loads in the direction of the beams. Joist slab: This is the best scheme if slabs are too long for a flat plate and the structure is not exposed. Flat slabs: These are most commonly used today for buildings supporting very heavy loads. Skip joist slab: This floor system should be less expensive than a joist slab for large projects; it permits lights and equipment to be recessed between joists. One-way beam and slab: This is the most favored scheme for parking garages. Waffle slab: Column spacing should be multiples of pan spacing to ensure uniformity of drop panels at each column. Drop panels can be diamond shaped, square, or rectangular. Two-way slab and beam: This scheme is used where unattractive unless heavy concentrated loads must be carried. CONCRETE FLOOR FINISHES Concrete floor finishes include performance, decorative, and textured applications. Textures can be achieved by stamping patterns into the uncured concrete surface. DESCRIPTION STONE FLOORING Stone flooring, or paving, in interior applications is a durable pedestrian traffic surface. Properly selected and installed, stone flooring wears well over time. Stone flooring can convey a sense of permanence and elegance, and is often used in lobbies and other public spaces. TYPES Numerous types of stones can be used for flooring, including slate, granite, travertine, marble, onyx, and sandstone. The selection of a stone should be appropriate for the intended use. Not all stones are capable of withstanding the traffic of commercial installations, so a review of stone types with the stone fabricator or supplier is recommended. Stone flooring is available in two basic types: dimension stone, which is installed in a thick mortar bed, and dimension stone tiles, which are installed in a thick mortar bed or in a thinset installation, similar to ceramic tile installations. DIMENSION STONE TILES Dimension stone is defined as quarried stone with usually one or more mechanically dressed surfaces. These are thick slabs of stone that are marked as they are cut for matched-pattern installations, such as book-matched or end-matched configurations. Dimension stone tiles are less than 3/4 in. (19 mm) thick. They provide the natural beauty of a stone floor without the weight, depth, and expense of dimension stone. However, their thinness makes stone tiles more prone to cracking from impact or normal floor deflection. Stone tiles are installed by either the thickset or the thinset installation methods. CONSIDERATIONS STONE PAVERS Most stones are adequately hard and sound to withstand the rigors of interior pedestrian and light vehicular traffic; however, each stone should be reviewed to determine its appropriateness for a particular paving application. FINISHES Stone finishes affect the perception of the color and the slip resistance of stone flooring. Common stone finishes include: • Polished finishes are the most reflective. These high-maintenance finishes should be selected with care. For high-traffic public areas, such as lobbies, polished floor finishes are often eventually hidden under nonskid mats. • Honed finishes have a dull sheen. These satin smooth surfaces are often good choices for commercial floors because of their slip resistance. • Thermal (flamed) finishes are achieved by the application of intense flaming heat to the surface of the stone. Thermal finishes are usually applied to granite. • Waterjet finish is a granite finish between honed and thermal. Created by high water pressure, a waterjet finish brings out the color of the stone, making it slightly darker than the thermal finish. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 192 I N T E R IO R CO NST RU CTION Page 192 INTERIOR F INISHES TYPICAL FINISHES AND COMMON SIZES OF STONE TILES AND PAVERS 7.364 STONE TILES: MINIMUM THICKNESS FINISH TILES: MAXIMUM FACE DIMENSION PAVERS: MINIMUM THICKNESS PAVERS: MAXIMUM FACE DIMENSION Ha 12 12 (305 305 mm) 1-1/4 to 4 (32 to 102 mm) 15 30 (381 914 mm) N/A Polished or honed tiles 1/4 to 1/2 (6 to 13 mm) 12 12 (305 305 mm) 1-1/4 (32 mm) 24 24 (610 610 mm) 10 Limestone Smooth — — 1-3/4 to 2-1/2 (44 to 64 mm) 24 36 (610 914 mm) 10 Slate Natural cleft or sand rubbed 1/4 to 1 (6 to 25 mm) 12 12 to 24 54 (305 305 to 610 1,372 mm) 1/4 to 1 (6 to 25 mm) 12 12 to 24 54 (305 305 to 610 1,372 mm) 8 Flagstone Natural cleft or semirubbed 1/2 to 4 (13 to 102 mm) 12 12 to 24 36 (305 305 to 610 914 mm) 1/2 to 4 (13 to 102 mm) 12 12 to 24 36 (305 305 to 610 914 mm) 8 Granite Polished, honed, 3/8, 1/2 (10, 13 mm) or thermal Marble STONE THRESHOLDS AND TRANSITIONS The 2010 ADA Standards for Accessible Design state that thresholds are considered changes in level, and are restricted in height STONE THRESHOLDS AND TRANSITIONS 7.365 and bevel. Vertical changes in level must not exceed 1/4 in. (6 mm). Changes in level between 1/4 and 1/2 in. (6 and 13 mm) in height must be beveled with a slope no greater than 1:2. Ramps are required for any changes in level greater than 1/2 in. (13 mm). 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 193 INTERIOR F INISHES STONE BASES 7.366 INTE R I O R CO N ST RU CT I O N 193 STONE STAIRS GLAZED AND UNGLAZED TILE Stone may be used on stairs as a finish material or can be supported by stringers to form structural treads. Fully supported treads are typically 3/4 to 1-1/4 in. (19 to 31 mm) thick. Stair substrates may be concrete or steel-framed treads and risers. Treads and risers are installed in a similar manner as stone flooring units, although the thinset adhesive method is recommended. Ceramic tile is either glazed or unglazed. CERAMIC TILE FLOOR FINISHES Ceramic tile is fabricated from clay or a mixture of clay and ceramic materials. Natural clay is most commonly used, but porcelain is also available. Porcelain tile is fine grained and smooth, and can be formed into sharply detailed designs. The following types of ceramic tile are used for floor finishes: • Ceramic mosaic tile is formed by either the dust-pressed or the plastic method. Usually 1/4 to 3/8 in. (6 to 10 mm) thick with a facial area of less than 6 sq in. (39 sq cm), it may be made of either porcelain or natural clay and may be plain or have an abrasive mixture throughout. Ceramic mosaic tile is usually mounted into units or sheets to facilitate handling and installation. • Quarry tile is glazed or unglazed tile made by the extrusion process from natural clay or shale. It usually has a facial area of 6 sq in. (39 sq cm) or more. Quarry tile may be specified with an abrasive grit that has been embedded in the surface for use in areas where slip resistance is a concern. Quarry tile can become slippery when it is exposed to grease. • Paver tile is glazed or unglazed porcelain, or natural clay tile formed by the dust-pressed method, with a facial area of 6 sq in. (39 sq cm) or more. • Conductive tile has specific properties of electrical conductivity but retains other normal physical properties of tile. CERAMIC MOSAIC TILE SHAPES 7.368 • Glazed tile has an impervious facial finish of ceramic materials that is fused to the body of the tile. The body may be nonvitreous, semivitreous, vitreous, or impervious. • Unglazed tile is a hard, dense tile of uniform composition that derives color and texture from the materials used in its fabrication. INSTALLATION Both thickset and thinset mortar installations can be used for floor tiles. THICKSET INSTALLATIONS Thickset mortar installations prevent the tile layer from being affected by minor cracking and movement of the substrate; this is very important over concrete, where cracks could damage the tile. Thickset installation is also used over structural slabs (not on grade) or where vibration or deflection may affect structures. Thickset mortar beds are used to level out uneven substrates. They are also used to create slopes in the tile layer, for example, around floor drains. Thickset mortar beds allow the installation of radiant hydronic tubing for heated floors, and protect metal, polyvinyl chloride (PVC), or chlorinated polyethylene (CPE) waterproof pans. The tile is adhered to a thickset mortar bed either when the mortar is just beginning to dry or after it is cured. The mortar bed may be reinforced with wire, and either set over a cleavage membrane that allows the mortar bed to float free of the substrate or be bonded directly to the substrate. THINSET INSTALLATIONS Thinset installations typically cost less than thickset installations and are faster to install. Because the tile is bonded directly to the substrate, variations or movement can affect the tile. A thinset layer is typically not more than 3/16 in. (4.8 mm) thick. Thinset mortar is not used to level surfaces, and will follow the plane of the substrate. Medium-bed thinset mortars adjust for slightly larger variations in the substrate than regular thinsets can. These thicker setting beds with coarser aggregate are used with large, heavy, or thick tiles to achieve a flat installation that will support the weight of the tile while it cures. FLOORING DETAILS—CONCRETE SUBSTRATE 7.369 CONTROL JOINT AND FULL MORTAR BED 7.367 Contributors: Building Stone Institute, New York, New York. George M. Whiteside III, AIA, and James D. Lloyd, Kennett Square, Pennsylvania. Tile Council of America, Inc., Anderson, South Carolina. Winnie Cheng, Rhode Island School of Design, Providence, Rhode Island. Jess McIlvain, AIA, CCS, CSI, Jess McIlvain and Associates, Bethesda, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 194 I N T E R IO R CO NST RU CTION FLOORING DETAILS—WOOD SUBSTRATE 7.370 Page 194 INTERIOR F INISHES STAIR NOSING PROFILES 7.372 AGGREGATE Aggregate is the term used for the stone chips used in terrazzo, which include all calcareous (such as limestone), serpentine, and other rocks capable of taking a good polish. Marble and onyx are the preferred materials. Quartz, granite, quartzite, and silica pebbles are used for rustic terrazzo and textured mosaics not requiring polishing. Other aggregate options include glass, synthetic materials, granite, and shells. Chips are graded by number according to marble industry standard sizes. Chips that pass a given size screen are bagged and sold as that size. Standard terrazzo is composed of #1 and #2 sized chips. Venetian terrazzo contains size #3 through #8 chips. Terrazzo with large 3/8 in. (10 mm) thick random fractured slabs of marble is called Palladiana. MATRICES There are two basic types of matrices, or binders: portland cement and resinous chemical binders. Color pigments are added to create special effects. Limeproof mineral pigments or compatible synthetic mineral pigments are required for use with portland cement. Portland cement matrices: Both white and gray portland cement are used; the final color varies with raw materials that may come from a wide variety of locations. White portland cement provides precise color control and combines well with tinting pigments. Gray portland cement provides less color uniformity and clarity; it normally costs less than white cement. TERRAZZO Terrazzo is a very low maintenance, seamless floor finish with the luxurious look of stone mosaic and durability comparable to that of concrete. Often selected for its decorative possibilities, terrazzo artists can produce striking medallions or intricate inlaid patterns. FLOORING DETAILS The detailing of ceramic tile flooring at edges and where the tile meets another material is critical in creating a smooth and durable floor. Stair nosings are available for use with ceramic or stone treads. Control and expansion joint profiles, designed for use with stone or ceramic tile flooring, are also available. Terrazzo is a mixture of a binder and crushed aggregate, typically marble. Divider strips of brass, white alloy of zinc, or plastic are used functionally as control joints, and aesthetically as design elements to separate fields of color. The use of metal dividers and the size of panels may affect the installation system that is used. EDGE PROTECTION AND TRANSITION PROFILES FOR FLOORS 7.371 Chemical matrices: Epoxy resin and polyacrylate are chemical terrazzo matrices. Resinous binders are used to install the thinnest possible finish of terrazzo, as thin as 1⁄4 in. (6 mm); usually only chip sizes #0 and #1 are used. Conductive terrazzo uses epoxy and polyester resin as the binder. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 195 INTERIOR F INISHES SURFACE TREATMENT TERRAZZO MATRIX SYSTEMS 7.373 TYPE OF SYSTEM INTE R I O R CO N ST RU CT I O N 195 DESCRIPTION ADVANTAGES DISADVANTAGES Portland cement on sand cushion or bonded acid-washed terrazzo Up to #7 chip size Can use breathable polyacrylate matrix terrazzo topping Interior or exterior use Acid washed for added exterior slip resistance Breathable, not affected by moisture vapor transmission Accommodates substrate defects Can be sloped to drains Can be used with radiant flooring systems Requires 2 (51-mm) depression for installation Limited color selection No glass chips allowed Panel size limitations Long cure time Epoxy resin matrix terrazzo 1/4 or 3/8 (6 or 10 mm) thick resin matrix veneer Can be used over concrete or wood substrate #0 to #1 chip sizes, #2 maximum for 3/8 (10 mm) thick topping Interior use only Weight 3 to 4 lb/sq ft (1.4 to 1.8 kg/0.9 sq m) Almost unlimited color range, color uniformity Marble, glass, synthetic, or granite aggregates Minimal divider strip requirements Faster cure times Substrate flatness requirement 1/2 (13 mm) per 10-0 (3 m) Not breathable, may require moisture vapor transmission barrier for slab on grade Polyacrylate-modified cement terrazzo Nominal 3/8 (10 mm) thick Can be used over concrete or wood substrate Interior or exterior use Chip sizes #0, #1, and #2 Weight 4.5 lb/sq ft (2 kg/0.9 sq m) Glass chips acceptable Breathable, not affected by moisture vapor transmission Can be acid washed for exterior slip resistance Substrate flatness requirement 1/2 (13 mm) per 10-0 (3 m) Maximum panel size without metal divider strips 8-0 8-0 (2.4 2.4 m) Limited vibrant colors TYPES OF TERRAZZO CLASSIFIED BY APPEARANCE 7.374 INSTALLATION SYSTEMS Terrazzo installation systems combine matrix type, topping thickness, and an underbed (if any) with substrate selection. In a terrazzo installation, the binder and aggregate mixture are set in place on the prepared floor surface. After the terrazzo surface has cured, it is ground down to a smooth finish. The floor is then grouted to fill any voids, and sealed. A terrazzo floor consists of at least 70% stone. For renovation work, terrazzo can be installed over practically any type of existing, stable hard-surface flooring. Precast terrazzo units are routinely available, and almost any shape can be produced. Examples include bases, windowsills, stair treads and risers, shower receptors, floor panels and tiles, planters and benches, and wall facings. Precast panels 1/4 or 3/8 in. (6 or 10 mm) thick are troweled, ground, and polished in the manufacturing facility before installation. Precast terrazzo floors can be installed at night and walked on the next day. DIVIDER STRIPS Terrazzo divider strips act as control joints, transitions between colors, transitions between vertical and horizontal panels, and terminations adjacent to other floor finishes. They are also used to create custom designs and patterns, including intricate logo artwork and lettering. Contributors: Tile Council of America, Inc., Anderson, South Carolina. Schlüter Systems, Plattsburgh, New York. Trey Klein, AIA, crayfish design, Belmont, Massachusetts. John C. Lunsford, AIA, Varney, Sexton Syndor Architects, Phoenix, Arizona. Jason Dickerson, Rhode Island School of Design, Providence, Rhode Island. INSTALLED DIVIDER STRIPS 7.375 Because porosity can vary among stone types, the pores of both the stone and the binder require the protection of a sealer to prevent absorption of traffic dirt and stains. Sealers will produce a high sheen and also highlight the natural colors of the aggregate. One or more coats of a mop-applied water-based acrylic sealer designed for terrazzo is recommended; this can be followed by an acrylic water-based finish for daily or weekly buffing to a high sheen. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 196 I N T E R IO R CO NST RU CTION Page 196 INTERIOR F INISHES A methyl methacrylate (MMA) system has a very fast cure time of 1 to 2 hours and it can be applied at much lower temperatures allowing it to be used in freezers and refrigerated areas. TERRAZZO INSTALLATION SYSTEM 7.376 Epoxy resin flooring comprises two-component systems that combine liquid resins and hardening/curing agents. Graded aggregates and mineral oxide pigments can be added to change color, texture, and performance characteristics of the finished floor. Static control epoxy resin flooring consists of carbon or other proprietary ingredients that have been added to the formulation for epoxy resin flooring systems. In a static-control application, the copper foil grounding grid is installed in the primer or base coat and is connected to the building’s grounding system. Polyurethane systems come in trowel-applied and poured, self-leveling formulations in thicknesses ranging from 1/8 to 3/8 in. (3 to 10 mm). Polyurethane is unaffected by freeze/thaw, live steam, and continuous hot water cleaning. Uses include food-processing facilities, commercial kitchens, freezers, and refrigerated storage. Latex resin flooring is trowel applied and jointless. It offers low absorption and good chemical resistance. Uses include showers, laboratories, animal research housing, pharmaceutical plants, and television studios. TERRAZZO BASES Terrazzo floor bases are designed to facilitate cleaning the angle between the floor and the wall. Most base details include a small cove where the floor and wall meet; canted bases open this up to a wider angle. Precast bases are designed either as two pieces at right angles or as a single piece with a cove. Bases can be set flush with the wall surface, recessed back from the wall face, or with a reveal between floor and wall materials. POURED FLOORING AND TREATMENTS Fluid-applied flooring systems provide seamless, durable coatings over concrete and other rigid substrates for commercial, industrial, and institutional applications. They are usually installed with an integral self-cove base. Magnesium oxychloride flooring is a fireproof, trowel-applied, seamless, hard-surface floor that is slip resistant when wet or dry. Durable and simple to install, it is used primarily in commercial kitchens and manufacturing locations such as welding shops. The standard color is red, although some earth tones are available. Fluid-applied athletic flooring: Unlike the other resinous floors described in this section, fluid-applied athletic flooring is a resilient system that replaces wood flooring in gymnasiums and multipurpose rooms. Fluid-applied athletic flooring is much less expensive than suspended wood floor systems. A typical installation is 1/2 in. (13 mm) thick, with the bottom 1/4 in. (6 mm) being the troweled cushion layer. TERRAZZO BASES 7.377 Contributor: National Terrazzo and Mosaic Association, Inc., Terrazzo Specification and Design Guide, Leesburg, Virginia. Margery Morgan, Symmes Maini & McKee Associates, Cambridge, Massachusetts. Seamless quartz flooring is seamless decorative flooring that consists of ceramic-coated quartz or colored quartz aggregates in clear epoxy. It is typically installed over a concrete substrate and is used in laboratories, locker rooms, and light-manufacturing and institutional facilities. MEMBRANES Membranes can be added to the composite of a fluid-applied flooring system to enhance its performance. Waterproofing membranes may be installed under systems subject to chemical spills that are located over occupied spaces. Flexible reinforcing membranes, often containing fiberglass scrim to maximize tensile strength, can be applied over the substrate to help prevent cracks from telegraphing through the fluid-applied flooring. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 197 INTERIOR F INISHES MAGNESIUM OXYCHLORIDE FLOORING 7.378 LAMINATE FLOORING Laminate flooring is manufactured much like plastic laminate countertop surfaces. It can often be installed over existing flooring. However, laminate flooring can be as expensive as solid wood, and cannot be refinished if it gets damaged. Laminate flooring is available as planks, usually about 8 in. (203 mm) wide and 4 ft (1.2 m) long, and as tiles. Both planks and tiles have tongue-and-groove edges that are joined with glue. Laminate trim pieces are available as well. Laminate flooring is made up of four layers: FLUID-APPLIED ATHLETIC FLOORING 7.379 • Top wear layer: This layer, made of cellulose paper impregnated with clear melamine resins, resists dents, scratches, burns, and fading. • Design layer: A design is printed on paper strengthened with resins. Designs are usually made to look like natural materials, but repeats may be noticeable when installed on the floor. • Core layer: This layer is made of engineered wood or fiberboard saturated with resins for durability. • Stability or balancing layer: Polymer-laminated paper on the back of the flooring adds dimensional stability. There are two methods of making laminate flooring: High-pressure lamination involves laminating the top and bottom layers separately with heat and pressure, then fusing them to the core with glue under more heat and pressure. High-pressure laminates are more impact and dent resistant than direct pressure products. Direct-pressure construction consists of assembling all the layers at once, then filling them with melamine resins under heat and pressure, to harden them. Direct-pressure laminates are less expensive than high-pressure laminates. POLYURETHANE FLOORING 7.380 SEAMLESS QUARTZ FLOORING 7.381 LAMINATE FLOORING 7.382 GLASS FLOORING 7.383 INTE R I O R CO N ST RU CT I O N 197 Because laminate flooring is not glued, nailed, or stapled to the subfloor, it will move as a unit when it shrinks or swells with changes in humidity. To allow for expansion, a 1/4-in. (6-mm) gap is left between the edge of the flooring and the walls. This is hidden by shoe molding. To keep expansion and contraction to a minimum, laminate flooring should be acclimated to building conditions for at least 48 hours before it is installed. An underlayment of solid panels is usually installed under laminate flooring on a wood subfloor; alternatively, foam, cork, or other underlayment materials can be used. The laminate flooring manufacturer may also recommend installation of a vapor barrier. GLASS FLOORING Glass floor panels are made from laminated glass, usually heat treated for additional strength. Laminating glass ensures that the panel will retain its structural integrity if the glass breaks. Fivelayer laminations are common. Heat-strengthened glass is preferable to fully tempered glass, because when fully tempered units crack, they lose a higher percentage of their structural capacity. Glass flooring is generally translucent, rather than fully transparent, for modesty, and because of the slip-resistant surface treatment. The walking surface is made slip resistant by sandblasting, cast texture, fired-on frit, or applied coatings. The glass panels are typically laid on gaskets over steel or aluminum frames, with traffic-grade silicone joint sealant. Panels can be supported on point support systems similar to those used for curtain walls. Laminated glass can also be used as a beam or joist to support glass floor panels. Joints are supported with gasketed shoes or clip angles. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 198 I N T E R IO R CO NST RU CTION Page 198 INTERIOR F INISHES WOOD FLOORING ENGINEERED WOOD FLOORING Wood flooring consists of solid or engineered wood products, and is available in strip, plank, and parquet flooring. All wood floors require regular maintenance to maintain their appearance. Engineered wood flooring is available in strip, plank, or parquet tiles. Hardwood face veneers are laminated to a dimensionally stable, multiple-ply substrate. Engineered wood floors are not as susceptible to moisture as solid wood flooring, and may be used in below-grade areas, with the proper installation techniques. Sustainable design issues should be considered in selecting wood flooring products. Look for Forest Stewardship Council (FSC) certification of solid wood sources. Avoid the use of rare or unsustainably produced woods. Consider using reclaimed or recycled wood. Engineered wood flooring products use limited amounts of more exotic wood as veneer on less valuable substrates. ENGINEERED WOOD FLOORING 7.385 In hardwoods, plain-sawn lumber generally contains mostly flatgrained wood, while quarter-sawn lumber is nearly all vertically grained. Figuring is the pattern produced in a wood surface by annual growth rings, rays, knots, and deviations from regular growth. Medullary rays radiate from the core of the tree toward the exterior bark. They vary in height from a few cells in some species to 4 in. (102 mm) or more in the oaks; they are responsible for the flake effect common to the quarter-sawn lumber in certain species. GRAIN Tangential grain is typically called flat grain; it is easily recognized by its parabolic (arched) effect. Lumber is considered flat grained when the annual growth rings make an angle of less than 45° with the wide surface of the board. TYPES SOLID WOOD FLOORING Solid wood flooring is available in many hardwood and softwood species. It can be refinished multiple times. Solid wood flooring should not be installed below grade, due to the possibility of moisture damage to the wood floor. Radial grain is known as vertical or edge grain. It is generally more stable than flat grain, and is less likely to expand or contract in width with changes in moisture. Lumber is considered vertical grained when the annual growth rings form an angle of 45° to 90° with the wide surface of the board. Oak is commonly used for residential floors. Red oak is dense and resistant to wear, with a somewhat coarse texture. White oak is a strong, durable wood with better water resistance than red oak. It has a coarse to medium texture. SELECTION DURABILITY Hard maple (Acer saccharum), not soft maple, is used for flooring. The Maple Flooring Manufacturers Association (MFMA) (www.maplefloor.org), states that beech and birch have physical properties that make them fully suitable as substitutes for hard maple. See the manufacturers for available width and thickness combinations. Wood flooring should be selected after considering pedestrian and vehicular (cart) traffic, durability required, and potential damage to floors; typical usage; exposure to moisture and sunlight; maintenance; wood floor appearance expectations; and other criteria specific to the project. The durability of wood flooring varies with the wood species and the finish selected. Hardwoods, such as oak and maple, typically perform better than softwoods, such as pine. Not all hardwoods are suitable for wood flooring. The wood species hardness and the cut of the wood flooring affect the wood’s ability to resist indentation, wear, and marring. Southern pine grain may be specified as edge (rift), near-rift, or flat. The majority of woods specified for commercial flooring are hardwoods such as oak or maple. Best overall appearance, uniformity of color, limited amounts of character marks, and minimal sap marks indicate the most desirable wood flooring. Western woods include Douglas fir, hemlock, Engelmann spruce, Idaho white pine, incense cedar, lodgepole pine, ponderosa pine, sugar pine, western larch, and western red cedar. Flooring is machined tongue and groove and may be furnished in any grade. Grain may be specified as vertical (VG), flat (FG), or mixed (MG). The basic size for flooring is 1 in. by 4 in. by 12 ft (25 mm by 101 mm by 3.6 m); standard lengths are 4 ft (1.2 m) and longer. WOOD STRIP FLOORING Wood strip flooring for normal use is typically a nominal 3/4 in. (19 mm) thick, with an actual thickness of 25/32 in. (19.8 mm), in widths ranging from 1-1/2 to 2-1/4 in. (38 to 57 mm). Lengths are random. WOOD CHARACTERISTICS Annual growth rings are visible in the wood and vary in color and density. The inner part of the growth ring is known as springwood, and has relatively large cell cavities and thin cell walls. Summerwood has smaller cell cavities and thicker, denser cell walls than springwood. Growth rings, when exposed by sawing methods, provide the grain and pattern in the wood flooring. GROWTH RINGS IN WOOD FLOORING 7.386 WOOD PLANK FLOORING Wood plank flooring is also typically a nominal 3/4 in. (19 mm) thick, in widths ranging from 3 to 10 in. (76 to 254 mm), and is available in random lengths. WOOD PARQUET FLOORING Wood parquet flooring consists of small wood strips, available in individual slats, or is formed into panels or tiles that are arranged to form a pattern. The thickness is typically 5/16 in. (7.9 mm) for individual strips and square panels. Source: National Wood Flooring Association, Manchester, Missouri. PARQUET FLOOR PATTERNS 7.384 Wood strip and plank flooring is quarter sawn (edge grain) or plain sawn (flat grain) and typically milled into a tongue-and-groove shape. Quarter-sawn strip flooring is considered to be more durable, due to the exposure of the vertical grain of the wood. It is also more expensive than plain-sawn wood, as more waste wood is generated. Rift-sawn strips are generally associated with oak flooring; it is also costly, as there is more waste than from quartersawn wood strips. Jointed, or square-edged, flooring is also available. End-grain wood blocks are durable flooring units, installed in a jointed fashion. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 199 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 199 FLOOR UNDERLAYMENT FOR SOUND CONTROL 7.391 CROSS SECTION OF LOG 7.387 RECLAIMED WOOD FLOORING Reclaimed wood is a source for flooring that does not deplete existing forests. Old buildings that are condemned, abandoned, or beyond repair, including barns, rural structures, factories and mills, and tobacco barns, are carefully deconstructed, and flooring, siding, and timbers are salvaged. Some reclaimed flooring manufacturers supplement these sources with newly felled trees from tree trimmers, developers, and landscapers; others use fallen or standing dead old-growth trees. Another source is narrow plank flooring recycled from buildings where it was formerly installed. WOOD FLOORING INSTALLATION Source: Maryrose McGowan, Specifying Interiors, John Wiley & Sons, New York, 1996, p. 171. CROSS-SECTIONAL DIMENSIONS 7.388 BOARD CHARACTERISTICS 7.390 Wood floors are installed over a plywood subfloor or over wood sleepers. Strips or planks are blind nailed in tongue-and-groove installations and face nailed in butt-jointed installations; parquet floors are commonly set in mastic. Vapor barriers are installed when the installation is slab on grade or below grade. Ventilation is required in certain installations where moisture is a concern. Special conditions require additional detailing for proper installation. BLIND-NAILED TONGUE-AND-GROOVE WOOD FLOORING 7.392 BOARD FLOORING THICKNESSES 7.389 UNDERLAYMENT SYSTEMS TO DAMPEN SOUND It is important to isolate wood flooring from the building structure in order to control impact sound. Acoustical underlayments can include cork, fiber matting, foam, or a composite membrane. Wood flooring can be directly glued to the acoustical material, which is glued to the subfloor. Engineered wood flooring can be floated over a foam pad. Strip or plank flooring can be nailed to a plywood subfloor that is floated over a layer of acoustical material, as long as the fasteners do not penetrate the acoustical material into the building’s structure to create a sound path. Systems must also be isolated from the wall. If impact sound is transmitted from the floor to the walls, the effectiveness of the system is greatly reduced. One basic key to peak performance is to avoid hard-surface transference points. The gap between the flooring system and the walls is generally filled with the same material as the underlayment. A small gap should be left between the base and shoe moldings and the floor. Contributors: Tom Lensment, Rhode Island School of Design, Providence, Rhode Island. Annica S. Emilsson, Rippeteau Architects, P.C., Washington, DC. National Wood Flooring Association, Manchester, Missouri. Suzanne Simpson, Gensler, Dallas, Texas. Source: Maryrose McGowan, Specifying Interiors, John Wiley & Sons, New York, 1996, p. 171. STRIPS OVER PLYWOOD UNDERLAYMENT 7.393 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 200 I N T E R IO R CO NST RU CTION STRIPS OVER CUSHIONED SLEEPERS 7.394 Page 200 INTERIOR F INISHES ORNATE WOOD FLOORING WOOD SUBFLOORS Vapor retarders are used between wood subflooring and the finish floor to slow the upward movement of moisture, helping to prevent occasional elevated moisture conditions below from buckling, cupping, or cracking the flooring. The National Wood Flooring Association recommends a perm rating of no less than 0.7 and no more than 50 for vapor retarders used between wood flooring and wood subflooring. Most ornate wood flooring contains certain common elements. The field is the main body of the floor. The field can be composed of a decorative pattern or straight flooring. A decorative element called a medallion is sometimes inserted into the center of the field. The field is often surrounded by a single board of contrasting color called an accent strip. Borders are decorative bands of flooring used to define an area such as the field of the floor. Borders may have a pattern that continues around the room uninterrupted or may be divided into segments. Corner blocks are used to divide the border into segments. V-blocks are also used to divide the border into segments but allow uninterrupted corners. An apron is an outside band of flooring that ties in the entire ornate design to the walls of the room. CONCRETE SLABS Concrete can supply large amounts of moisture that can damage wood flooring. A vapor retarder with a perm rating of 0.13 or lower installed between the concrete and the wood flooring is imperative to avoid future problems. WOOD FLOOR FINISHES STRIPS OVER SUBFLOOR ON WOOD JOISTS 7.395 Wood inlays can be made from full-thickness flooring or from veneers affixed to plywood. The engineered type performs best due to the stability of the plywood. Wood floors must be finished to protect the surface from wear. Applied finishes can be installed in the field or, in the case of engineered wood floors, they can be factory finished. Floor finishes do not protect the wood from the effects of ultraviolet (UV) light, which can alter the appearance of the wood. Some species of wood are more susceptible to change when exposed to sunlight; however, UV inhibitors are available to minimize fading. Stone inlays are installed after the floor is installed and finished. The stone is generally veneer around 3/8 in. (10 mm) thick, and is mounted to a plywood backing. FIELD FINISHES Soft metals such as brass, aluminum, and copper can be inlayed into wood floors. Ferrous metals that can rust are not recommended. Metal inlay material is generally 1/4 in. (6 mm) thick. Unfinished wood flooring can be stained to achieve an exact color match with other design elements or to mimic the appearance of a softer wood that might not have met the performance expectations of the installation. Paint, stains, and dyes can be utilized to add accents to a wood floor or imitate inlays of more expensive materials. Stains and dyes should be directly applied to bare wood. Before the application of a field finish, wood floors are sanded so that they are level and smooth, and then one of several finishes is applied. All of these finishes are subject to wear and must be touched up or removed and reapplied during the life of the floor. FACTORY FINISHES Acrylic-impregnated (sometimes called irradiated polymer) wood flooring is extremely durable. This finish imparts many of the qualities of resilient flooring to the wood, such as an increased resistance to abrasion and bacterial growth. The process involves removing the air from the pores of dried wood and forcing liquid acrylic into the voids. The plastic-filled wood is then irradiated (exposed to radiation), causing the acrylic to polymerize. VAPOR RETARDERS Water vapor in buildings travels from areas of higher temperature and relative humidity to areas of lower temperature and humidity. The greater the vapor pressure difference, the faster the moisture vapor will travel. Aluminum oxide and polymerized titanium oxide finishes are applied in multiple coats, and are very durable. Prefinished wood flooring is also available with multiple coats of polyurethane or other proprietary finishes. The rate of diffusion through a material depends on the material’s permeability (perm rating) and the degree of vapor pressure that pushes the moisture through the material. Permeability is a measure of the amount of water vapor that can pass through a specified material in a certain amount of time. The degree of permeability is expressed in perms. Materials with high perm values allow more moisture to pass through than those with lower perm values. WOOD FLOOR FINISHES—FIELD APPLIED 7.397 Water vapor permeance is very sensitive to relative humidity gradients. In other words, the greater the difference in relative humidity between the two sides, the more water vapor will pass. CLASSES OF VAPOR RETARDERS 7.396 CLASS PERMS Vapor impermeable 0.1 perm or less Vapor semi-impermeable 1.0 perm or less and greater than 0.1 perm Vapor semipermeable 10 perms or less and greater than 1.0 perm Vapor permeable Greater than 10 perms Contributors: Charles Peterson, Gales Ferry, Connecticut. FINISH TYPE DESCRIPTION CHARACTERISTICS APPLICATION Oil-modified urethane Solvent-based polyurethane Ambers Easy to apply, 8-hour dry time Water-borne acrylic Appearance same as other water-borne finishes Least durable Least expensive Used for sealer, where durability is not an issue Moisture-cured urethane Solvent-based polyurethane Nonyellowing and ambering types More durable, more moisture resistant Satin or gloss finish Extremely difficult to apply, strong odor; professional applicator recommended Conversion varnish Two components: synthetic resin, acid catalyst Clear to slight amber Durable Extremely strong odor Highly skilled professional applicator recommended Water-based urethane finishes Water-based polyurethane Clear, nonyellowing, not as durable as solvent based Mild odor, dries 2 to 3 hours Two-component urethanes Water-based polyurethae with catalyst Nonambering Very durable Catalyst quickly hardens finish layer UV-cured finishes Cross-links free radicals to cure instantly Most durable Most chemical-resistant Low VOCs Site applied using UV light on mobile cart Penetrating stain and wax Solvent-based stain and wax Soaks into wood pores, hardens to protective penetrating seal Low-gloss satin sheen Maintain with solvent-based (not water-based) waxes, buffing pastes, or cleaning liquids made specifically for wax-finished wood floors 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 201 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 201 RADIANT HEATING AND WOOD FLOORS ORNATE WOOD FLOORING 7.398 Radiant heating provides a very comfortable heat by directly warming the floor. Underfloor radiant heating is hidden in the subfloor system. It does not waste valuable wall space with unsightly heating equipment. The systems depend largely on radiant heat transfer but also on convection, the natural circulation of heat within a room, caused by heat rising from the floor. Radiant heating systems are generally either warm water systems or electric systems. The systems can be poured into a masonry mix or fastened directly to the subfloor. Radiant heating systems for wood floors are almost exclusively hydronic (liquid) systems. They are the most popular and cost effective type of heating systems for most climates. Radiant floor systems pump heated water from a boiler through tubing laid in a pattern underneath the floor. The temperature in each room is controlled by regulating the flow of hot water through each tubing loop. With the heating source located directly beneath the flooring, extra care must be taken with the design and installation of the system. Radiant heating systems can excessively dry out the wood flooring. The maximum surface temperature of the subfloor should be limited to 85°F. RADIANT-HEATED GLUE-DOWN, ENGINEERED, OR SOLID PARQUET FLOORS 7.399 RESILIENT WOOD FLOORING Resilient wood flooring is commonly used in athletic facilities. The typical wood flooring species for sports facilities is maple, which is preferred due to its density, fineness of grain, and nonsplintering qualities. Beech and birch are also used by some manufacturers for resilient wood floors. Finishes are typically transparent, and supplemental markings may be added with approved materials and techniques for floor striping and logos. Wood sports floors are sanded, sealed, and finished with at least two coats of sealer and two coats of finish. Game lines are painted between the last coat of sealer and the first coat of finish. Game-line paint must be compatible with the sealer and finish. BAMBOO FLOORING Bamboo is a grass (not a wood, strictly defined). It grows quickly, regenerates without replanting, and uses little fertilizer or pesticides. The bamboo is harvested, cut into strips, boiled in water with a preservative, and pressed flat. The strips are then dried and laminated into solid boards, which are very hard and dimensionally stable. Bamboo flooring is very durable; hardness tests indicate that bamboo floors are comparable to red oak floors. Contributors: Charles Peterson, Gales Ferry, Connecticut. Annica S. Emilsson, Rippeteau Architects, P.C., Washington, DC. National Wood Flooring Association, Manchester, Missouri. Corky Binggeli, Materials for Interior Environments, John Wiley & Sons, Hoboken, NJ, 2008. Bamboo boards are assembled in three ways: vertically, horizontally, and strand-woven. Bamboo strips 1 in. (25 mm) wide are placed in flat side-by-side layers (horizontal) or are set on their thin edges vertically. Strand-woven bamboo makes use of material left over from the production of horizontal or vertical bamboo products. Strands are intertwined, compressed, and bounded with a UV, scratch, and moisture-resistant resin. The resulting very hard and very durable material is cut into planks. By itself, bamboo is an environmentally friendly material. However, bamboo products such as flooring are often assembled using an adhesive resin containing formaldehyde. Low-VOC bamboo flooring with formaldehyde-free adhesives is available. Another environmental consideration is that bamboo products must be shipped a great distance to reach the U.S. market. Bamboo is available in two colors: natural and carbonized. Natural bamboo is a creamy blonde color. Carbonized bamboo’s smoky caramel color is a result of longer boiling, which caramelizes the starches in the bamboo; it also reduces the hardness by 30%. Some carbonized bamboo also includes carbon or charcoal. Bamboo flooring is manufactured in tongue-and-groove strips approximately 3-1/2 in. (89 mm) wide, 3/4 in. (19 mm) thick, and in lengths up to 6 ft (1.8 m). A 3/8 in. (10 mm) thick material is available for glue-down application. RESILIENT FLOORING Resilient flooring provides a dense, nonabsorbent, pliant surface that is generally quiet, comfortable to walk on, and easy to maintain. Resilient flooring types include sheet linoleum, cork, rubber, sheet vinyl, vinyl tile, and leather. Factors to consider in choosing a resilient flooring type include cost, performance, durability, availability, energy and natural resource use, biodegradability, recycled content, recyclability, and toxicity. TYPES LINOLEUM Linoleum produced for residential and commercial use today is significantly different from the linoleum used in mid-20th-century kitchens and bathrooms. Linoleum is a suitable material for heavy use in commercial installations. It is used where superior resilience is required, such as the floors of dance rehearsal studios and healthcare facilities. Linoleum products are available with cork added for comfort and shock absorption, with recycled rubber shock-absorbing subfloors attached, and for surface applications on bulletin boards, walls, furniture, door panels, and cabinets. Linoleum (derived from the Latin terms for “flax,” linum, and “oil,” oleum) is composed primarily of linseed oil, obtained from the flax plant. The oil is oxidized and mixed with a natural resin, such as rosin tapped from pine trees, and combined with powdered cork for flexibility and limestone for strength and hardness. Wood flour 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 202 I N T E R IO R CO NST RU CTION and pigments are added for color and colorfastness. Color is consistent from the face to the backing. For dimensional stability, this mixture is bonded to a fiber backing (typically burlap) for linoleum sheets or to a polyester backing for tile. Felt backings are used for linoleum countertop or tack surface sheets. Page 202 INTERIOR F INISHES LAMINATED RUBBER TILE 7.401 Rubber flooring is dimensionally stable, sound absorbent, and recyclable. It is resistant to heavy-impact loads, and is punctureresistant. PROPERTIES Linoleum is biodegradable and is considered an environmentally sustainable product. Linoleum is a superior thermal and acoustical insulator because of the air pockets found naturally in cork (50% air). Linoleum thickness varies between 0.08 and 0.16 in. (2 and 4 mm). It is naturally bacteria resistant and antimicrobial, preventing the growth of dust mites. The antistatic properties of linoleum prevent dust accumulation and reduce the potential for electric shock, and conductive linoleum is available. RUBBER ATHLETIC FLOORING Flooring made of compressed rubber particles is available in rolls, square tiles, and interlocking tiles for use in fitness clubs and athletic facilities. It is dense enough to withstand use in ice skating rink surrounds and in weight rooms. INSTALLATION Linoleum can be cut by the waterjet process to produce custom designs and logos. Linoleum seams can be heat welded for water resistance, in areas over radiant floors and those exposed to direct sunlight. Manufacturers can supply nonsoiling multicolor welding rods that are invisible when installed in matching flooring. LINOLEUM TILE 7.402 CORK Cork is harvested from the outer layer of cork oak trees grown in Mediterranean regions. The bark becomes loose approximately every nine years, and is cut away. Composition cork is the most common form of cork flooring; the bark material of the cork oak is granulated, pressed with binders such as synthetic resins, and then baked. The quality of composition cork varies according to the quality and size of the granules, the type and quantity of the binder, and the density (compression) of the mix. Cork flooring is inherently antistatic, hypoallergenic, and nonslip. It provides excellent acoustical and thermal insulation. Cork is also used as an underlayment to increase the resiliency of other types of finish floors. It is temperature sensitive and should not be used in combination with underfloor heating systems. The slip resistance of homogeneous rubber tile is enhanced by adding raised surface patterns, although these may accumulate dirt. This material is often used as stair treads and nosings. Rubber athletic flooring is available in thicknesses of 5/32, 1/4, 3/8, and 1/2 in. (5, 6, 10, and 13 mm). Rolls are typically 4 ft (1.2 m) wide, and tiles 3 ft (0.9 m) square. Rubber athletic flooring is usually solid black or black with 10 or 20% of a wide variety of colors; custom blends and other background colors are available. Rubber athletic flooring can be installed on a variety of substrates, including dry concrete and wood. Moisture in the substrate can cause problems with the adhesives. Full glue-down application is recommended, although taped installation is sometimes used in areas with light use. Flooring materials should be unpacked or unrolled and allowed to acclimate for at least 12 hours before installation. RUBBER ATHLETIC FLOORING 7.405 LEATHER TILE 7.403 TYPES Unfinished tile is the standard cork flooring product form. Also available are prefinished cork with a urethane top coating, vinylclad cork, or floating cork floors that either glue or mechanically snap together and float over a thin cork underlayment. Cork sheets and rolls are available with jute backing, but these are difficult to install. Cork is naturally honey toned but is available in other colors. VINYL Today, environmental and health concerns are leading specifiers to reject vinyl as a floor finish. Vinyl products do not break down in landfills. Architects and designers should seek alternative materials that are less damaging to the environment and to human health. RUBBER Rubber sheet or rubber tile flooring is composed of natural rubber and/or synthetic rubber (styrene butadiene), mineral fillers, and pigments. Rubber is an excellent finish for high-traffic areas. Durable, resilient, and resistant to a wide variety of harsh chemicals and solvents, rubber flooring is naturally resistant to cosmetic burns. Rubber flooring can tolerate high traffic in public areas such as transportation terminals. However, it can be dented by heavy furniture or equipment concentrated on a small area. RUBBER TILE WITH RAISED PATTERN 7.400 SHEET VINYL COMPOSITION CORK TILE 7.404 Sheet vinyl flooring comes in 6 or 12 ft (1.8 or 3.7 m) widths and forms a continuous finished floor covering. Because sheet vinyl flooring has fewer joints than tile, it is used for applications where spills, dirt, or bacterial growth are of concern. It has been commonly specified in hospital operating rooms or other areas where resistance to bacterial growth or water penetration is required. Homogeneous, or solid, sheet vinyl floorings, have no backing. Homogeneous sheet vinyl has superior resistance to indentation, rolling loads, and chemicals, and is suitable for heavy-wear applications because its appearance remains consistent even when GRADES OF SHEET VINYL FLOOR COVERING WITH BACKING 7.406 TYPE I II Contributor: Faith Baum, AIA, IIDA, Faith Baum Architect, Lexington, Massachusetts. GRADE WEAR LAYER THICKNESS, MINIMUM 1 0.020 (0.51 mm) 2 0.014 (0.36 mm) 3 0.010 (0.25 mm) 1 0.050 (1.27 mm) 2 0.030 (0.76 mm) 3 0.020 (0.51 mm) 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 203 INTERIOR F INISHES worn. It contains much more PVC than backed sheet vinyls, making it more resilient and more expensive. Backed sheet vinyl is available in two constructions, felt, which accounts for over 90% of current purchases, and fiberglass, a newer process with more resiliency and a variety of installation options. The upper layers of both types are the same, as follows: • Protective top coat: Usually made of urethane, this layer resists scratches and scuffs and facilitates ease of maintenance. • Protective clear vinyl layer: This layer avoids rips, tears, and TYPES OF VINYL SHEET FLOORING 7.407 INTE R I O R CO N ST RU CT I O N 203 gouges. A thicker clear vinyl layer results in improved appearance retention and durability. • Printed vinyl design layer: A wide variety of designs and patterns are produced using the rotogravure process. The bottom layers of the two constructions differ: • Felt bottom layers are adhered directly to the subfloor. • Fiberglass bottom layers are more dimensionally stable than felt, and install without glue. A cushioning vinyl backing adds resilience VINYL TILE Two types of vinyl tile are solid vinyl tile and the less expensive vinyl composition tile (VCT). Solid vinyl tile, or homogeneous vinyl tile, contains much more PVC than VCT, making it more resilient and resistant to abrasion. Homogeneous vinyl tile has superior indentation and rolling/load resistance. Because the pattern is continuous through the thickness of the flooring, its appearance will remain consistent when worn. Three classes of VCT are defined by ASTM F 1066, Standard Specification for Vinyl Composition Floor Tile: • Type 1, solid color tiles • Type 2, through-pattern tiles • Type 3, surface pattern tiles Vinyl composition tile is more brittle than vinyl sheet flooring because it contains much less PVC. VCT is composed mostly of fillers with comparatively small amounts of binder and pigments. Vinyl tile is less expensive to install than sheet vinyl and easier to replace in damaged areas. Tile layout should consider the center of the room and the size of the last tile that falls at the perimeter. Typically, it is desirable for the perimeter tiles to be as large as possible and no smaller than a half-tile wide. Vinyl tile is now available in three installation options, including the following: • Glueless: Adhesive tabs or spray adhesive • Peel and stick: Self adhesive; no glue needed • Full-spread : Adhesive applied with a trowel LEATHER TILE Leather tiles are typically cut from the center of a cowhide (usually a by-product of the food industry), where the fibers are tightest. The leather is vegetable tanned and colored with penetrating aniline dyes. Leather tiles can be relatively expensive compared to other resilient flooring choices. Leather tiles will have natural grain and color variations. Leather tile flooring develops a patina over time as it wears and oxidizes in light and air. RESILIENT FLOORING SIZES 7.408 TYPE COMPONENTS THICKNESS SIZES Vinyl sheet Vinyl resins with fiber back 0.065 to 0.160 (1.7 to 4 mm) 6-0, 10-0, 12-0 (1.8, 3, 3.6 m) wide Solid vinyl tile Vinyl resins 1⁄16 to 1⁄8 (1.5 to 3 mm) 9 9 (228 228 mm) Vinyl composition tile Vinyl resins with filler 0.050 to 0.095 (1.3 to 2.4 mm) 9 9 (228 228 mm) Rubber tile Rubber compound 3⁄32 to 3⁄16 (2.4 to 4.8 mm) 9 9 (228 228 mm) Cork tile Raw cork and resins 1⁄8 to 1⁄4 (3 to 6 mm) 6 6 (152 152 mm) Cork tile with vinyl coating Raw cork with vinyl resins 1⁄8 to 3⁄16 (3 to 4.8 mm) 9 9 (228 228 mm) 12 12 (305 ´ 305 mm) 12 12 (305 305 mm) 12 12 (305 305 mm) 9 9 (228 228 mm) 12 12 (305 305 mm) RESILIENT FLOORING COMPARISONS 7.409 TYPE RESILIENCE DURABILITY FINISH MAINTENANCE ENVIRONMENT AND HEALTH Cork Very good Absorbs moisture, stains Factory vinyl topcoat or oil finish Resists mold, mildew Fades, yellows in sun Do not wet mop Natural, renewable material. May be mixed with synthetic resins Linoleum Very good Extremely durable Manufacturer’s two-layer water-based finish, or waxed finish Resists staining, grease, burns Natural biodegradable materials Rubber Very good Durable enough for high-use spaces Slippery when greasy May require sealer Self-polishing floors available Raised patterns may collect dirt Mop regularly Resists chemicals, burns Synthetic (styrene butadiene) or natural rubber Recyclable Vinyl sheet Very good Moderately durable, recommend min. 10 mil wear layer No-wax finish (will lose shine), or waxed finish Resists staining, grease, burns Requires rebuffing or recoating Fading, blisters, brittleness in sun High PVC content High VOCs Toxic gases if burned, not recyclable, not biodegradable Solid vinyl tile Good Durable Pattern throughout tile Vacuum, wipe up spills Less PVC than sheet vinyl, same disposal problems Vinyl composition tile Moderate Moderately durable Thin wear layer may wear off Resists staining, grease, burns Less PVC than vinyl tile, same disposal problems Source: Adapted from Corky Binggeli, Materials for Interior Environments, John Wiley & Sons, Hoboken, NJ, 2008. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 204 I N T E R IO R CO NST RU CTION RESILIENT FLOORING INSTALLATION RESILIENT TILE Most resilient floor tile is installed as manufactured without any type of seam treatment; there are some exceptions such as products that are heat welded. RESILIENT SHEET FLOORING SEAMS Resilient sheet goods, such as sheet vinyl, linoleum, and sheet rubber, involve careful seaming techniques. Sheet flooring must be trimmed at all edges that are to be butted together. Seams are sealed either with a chemical seam sealer or by heat welding. Page 204 INTERIOR F INISHES RESILIENT BASE MATERIALS 7.410 MATERIAL RESPONSE TO HEAT FLEXIBILITY Good Excellent $ Thermoplastic rubber Expands Better Good $$ Thermoset rubber Expands Best Fair $$$ WALL BASE 7.411 Welding uses a hot air gun designed for this purpose. The tip is interchangeable. The proper size tip must be used based on the diameter of the welding rod. If the tip is too large to accept the welding rod, the floor covering material can be damaged during the welding procedure. CUSTOM DESIGNS Historically, resilient flooring products have been used in combinations of colors to create distinctive visual designs. This can be as simple as a border or checkerboard design in resilient floor tile or as complex as a company logo or other artwork cut into the floor. Skilled craftspeople can do this work by hand, but increasingly this cutting is done using technology such as waterjet or ultrasonic cutting (laser cutting involves too much heat) that converts the designer’s concept into a finished product that is delivered to the job site ready to install. RESILIENT BASE AND ACCESSORIES Resilient wall base and flooring accessories are available in three materials: WALL BASE Wall base conceals the joint where the wall meets the floor. Sheet goods, such as linoleum or sheet vinyl, can form an integral, monolithic cove base to simplify maintenance. There are three basic wall base profiles: • Straight base is meant to be used with carpet. • Cove base is meant to be used with resilient flooring. • Butt-to base, sometimes referred to as sanitary base, is available from a limited number of manufacturers. It is installed prior to the finish floor covering. The finish floor covering must be of the same thickness as the butt-to-base flange. The base is sealed to the floor and wall, creating an easy-to-clean, more sanitary joint that is popular for healthcare applications. Cove moldings support sheet vinyl, sheet linoleum, or other flexible floor coverings when coved up the wall. Cap moldings help to finish the exposed edges of coved floor coverings, ceramic tile, or wood paneling TRANSITION MOLDINGS Transition moldings create a smooth transition between different flooring materials or flooring heights and act to conceal seams. Snap-in moldings offer the advantage of wear-edge replacement without disrupting the flooring installation. Contributors: Mia Alwen and Lerlux Sophonpanich, Rhode Island School of Design, Providence, Rhode Island. Christopher Capobianco, Christopher Collaborative Inc., Patchogue, New York. RELATIVE COST Shrinks Grooving resilient flooring to receive heat-welded seams can be done by hand or with electric tools. Tools must be specifically designed for heat-welded seams and must be the proper size, based on the size of the manufacturer’s welding rod. • Vinyl can be susceptible to shrinking when exposed to heat and, as indicated above, has health and environmental problems. • Thermoplastic rubber is a vinyl compound with a comparatively small amount of rubber added for flexibility. Because of the high vinyl content, it performs similarly to vinyl, but is more flexible. • Thermoset rubber is vulcanized natural rubber. It is the most flexible resilient base material and thus is easier to install and better at hiding surface imperfections in walls and floors. RESISTANCE GREASE/OIL Vinyl Source: Steven R. Breuer, AIA, LEED AP, lauckgroup, Dallas, Texas. RESILIENT TRANSITION MOLDINGS 7.412 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 205 INTERIOR F INISHES STATIC-CONTROL FLOORING The electronics and computer industries are the primary markets for static-control flooring. There are two types of static-control flooring: static dissipative and conductive. The basic difference is the rate at which an electric charge moves through the floor. TYPES Static-control resilient flooring consists of resilient tiles or sheet material applied to a substrate using static-control adhesive with embedded grounding strips. Joints in the vinyl products can be heat welded for a seamless installation. They come in various colors, some with a characteristic thin, black thread pattern caused by the encapsulated carbon that provides the electrostatic control. Integral self-cove bases can be constructed from the solid vinyl tiles and sheet vinyl materials. CARPET, CARPET TILE, AND MATS CARPET CONSTRUCTION Carpet construction refers to the carpet manufacturing method. The three most popular construction methods for commercial carpet construction are tufting, weaving, and fusion bonding. Commercial loop carpets may be loop, cut pile, or combinations of the two. Handtufted carpets are often specified for hospitality applications. Knitted and needle-punched carpets are available but less often specified. Residential tufted carpets are often constructed with cut pile, level loop, patterned loop, and cut and loop methods. • Tufted carpets account for as much as 95% of the carpet produced in the United States. • Woven carpets are made on a loom using the original carpet construction method. • Fusion-bonded carpet tiles dominate the carpet tile market in the United States. • Knitted carpets use more face yarn than tufting. • Needle-punched carpets are formed by hundreds of barbed needles punching through blankets of fiber. TUFTED CARPET Compared to other carpet construction methods, tufting does not require skilled labor and requires less expensive equipment to manufacture. It is far less expensive and faster to produce tufted rather than woven carpets. This process has enabled the mass production of an affordably priced, wide-width textile floor covering. The tufted construction process is similar to sewing. Hundreds of needles stitch simultaneously through a backing material. To hold the tufted loops in place, the underside of the primary backing is usually coated with a synthetic latex adhesive, a rubbery substance that dries hard but remains bendable. A secondary backing material is then applied. Primary backing materials are the woven or nonwoven fabrics into which the tufts are inserted. They are typically olefin based, either plain woven or spunbonded. A thin polymer coating is often applied to bond the warp and weft threads and to minimize unraveling. Contributors: Steven R. Breuer, AIA, LEED AP, lauckgroup, Dallas, Texas. Margery Morgan, Symmes Maini & McKee Associates, Cambridge, Massachusetts. INTE R I O R CO N ST RU CT I O N 205 CARPET BACKING MATERIALS 7.413 MATERIAL SOURCE HEALTH AND ENVIRONMENTAL CONSIDERATIONS Polyvinyl chloride (PVC) Petrochemical Toxic throughout life cycle; backing recycled with nylon face (downcycled) Polyolefin Petrochemical Backing separated from face fiber for closed-loop recycling Polyvinyl butyral (PVB) Petrochemical; can be made from recycled lamination sheets in safety glass No chlorine as in PVC Urethane Petrochemical; some other sources, including soybean oil Generally not recyclable Polypropylene Petrochemical Usually residential use Jute Natural plant product Less durable than petrochemical products; residential use Styrene butadiene (SB) latex Synthetic petroleum-based water emulsion Usually does not trigger latex allergies; manufacturing involves toxic chemicals CARPET BACKING SYSTEMS 7.414 CONSTRUCTION METHOD TYPICAL BACKING OR BACKING COMPONENTS TYPICAL BACKCOATING CHEMICAL COMPOUNDS Tufted Primary: Woven polypropylene slit film Nonwoven polypropylene or polyester Secondary: Woven leno weave polypropylene Nonwoven polypropylene or polyester Woven jute Fiberglass reinforcement Synthetic styrene butadiene rubber (SBR) latex Polyurethane Polyvinyl acetate Ethylene vinyl acetate Polyvinyl chloride Amorphous resins Thermoplastic polyolefin Fusion bonded Fiberglass matting Polyvinyl chloride Woven Construction yarns may include: Cotton Jute Polypropylene Polyester Viscose rayon Blends or combinations Similar materials to tufted, but usually thinner coatings Hand tufted Cotton canvas Latex Needle punched (None typically used) SBR latex Acrylics Ethylene vinyl acetate SBR latex foam Spunbonded olefin is inherently resistant to fraying or unraveling. During the tufting process, the olefin fibers are pushed aside, minimizing the distortion of the backing. This helps ensure a uniform pile height. Backings made of olefin are impervious to moisture and are mildew resistant. Adhesives used in tufted carpet are usually synthetic latex. Molten thermoplastic compounds are also used. Adhesives permanently anchor the tufts to the primary backing, preventing snags and unraveling. Secondary backing materials, sometimes referred to as scrims, provide dimensional stability to the finished tufted carpet. A secondary backing is added for strength and stability. Secondary backing materials are often made of polypropylene, which is popular because it is moisture resistant. Alternatives to secondary backings are attached carpet cushions, solid vinyl composites, and coatings referred to as unitary backings. The standard dimension of most manufactured tufted carpet is a 12 ft (3.6 m) width, although some manufacturers provide 6 ft (1.8 m) and 15 ft (4.5 m) widths for special applications. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 206 I N T E R IO R CO NST RU CTION TUFTED CARPET 7.415 Page 206 INTERIOR F INISHES ACCESSIBILITY REQUIREMENTS FOR CARPET The 2010 Standards for Accessible Design apply to floor finishes, including carpet. Verify requirements with local code authorities. The following issues should be considered: • Changes in level up to 1/4 in. (6 mm) may be vertical and without an edge. • Changes in level between 1/4 and 1/2 in. (6 and 13 mm) should be beveled with a slope no greater than 1:2. Changes in level greater than 1/2 in. (13 mm) should be accomplished by means of a ramp. • Carpet having a pile height of 1/2 in. (13 mm) measured from the bottom of the tuft is allowed. Exposed edges should be secured and have a transition strip. Pile heights over 1/2 in. (13 mm) must have a transition ramp between the surfaces. • Carpet should be securely attached, have a firm cushion or backing, or no cushion, and have a level loop, textured loop, level cut pile, or level cut/uncut pile. ACCESSIBLE ROUTE CHANGES IN LEVEL UP TO 1/4 IN. (6 MM) 7.416 ACCESSIBLE ROUTE CHANGES IN LEVEL BETWEEN 1/4 AND 1/2 IN. (6 AND 13 MM) 7.417 ADA CARPET PILE THICKNESS 7.418 CARPET TILE Carpet tiles provide ready access to a raised floor or easy replacement when soiled or worn. Tiles are available as 18 in. (46 mm), 19.7 in. (50 cm), 36 in. (91 cm), and sometimes 6 ft (1.8 m) squares. Carpet tiles are often more expensive than broadloom carpets. The seams are highly visible, which some manufacturers use as a modular design element. Pile types include cut pile and loop pile, along with fusion bonding. Tiles are available with low levels of volatile organic compounds (VOCs). Some manufacturers offer tiles containing recycled and renewable raw materials, as well as return and recycle programs. Common face fibers include nylon, polyester, and wool. Fusion bonding is the most common method of carpet tile construction. It is a thermoplastic process, whereby yarns are attached to a backing material by means of adhesion rather than stitching (as in tufted carpet) or weaving. The adhesive is applied to the backing material, and the yarns are implanted in it. Because the yarn is typically embedded between two parallel backings that must be sliced apart, fusion-bonded carpet is necessarily cut pile. Fusion-bonded carpet has the greatest percentage of yarn available for wear, but is more expensive than tufted carpet. The cut pile construction of fusion bonding offers greater pile densities at comparable yarn weights than tufted constructions. Dimensional stability is the prime characteristic in carpet tile selection. Tiles should be covered by warranty against shrinkage, edge curling (also called tile lifting), and buckling. Carpet tiles are installed with standard adhesives, releasable adhesives, and mill-applied peel-and-stick adhesives. Adhesive dots or tacking squares that attach tiles together at their edges are also available. Carpet tile installation is easier and causes less downtime and productivity loss than traditional carpet installation. WOVEN CARPET Weaving, the traditional method used for carpet construction, produces a carpet on a loom, integrating the pile and backing yarns during the carpet construction. Most woven carpet is dimensionally stable as a result of the weaving process and does not require a secondary backing, as a tufted carpet does. Weaving accounts for less than 2% of the carpet market in the United States. Its primary use is in the hospitality industry, where long-term durability and intricate pattern detail are primary considerations. There are three basic types of weaving processes: velvet, Wilton, and Axminster. • Wilton carpets are limited to about five changes in yarn color. A Wilton carpet is thick and heavy because every color yarn used is carried beneath the pile surface. • Axminster carpets enable virtually limitless patterns and colors, because the colored yarns are inserted individually as required by the design. Axminsters are cut pile face construction. • Velvet carpets are made on looms that are similar to Wilton looms, but without the Jacquard mechanism, so intricate details and elaborate patterns are not available. FUSION-BONDED CARPET 7.419 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 207 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 207 CARPET TILE INSTALLATION PATTERNS 7.420 WOVEN CARPET 7.421 HAND-TUFTED CARPET Hand-tufted rugs are most often custom designed for a specific space. They are commonly made of wool and are popular for hospitality and high-end residential applications. Wool yarns are often dyed specifically for a hand-tufted rug. Hand-tufted rugs are made by inserting tufts one at a time by hand, with a tufting gun, into a backing, which is typically cotton canvas. The tufts are not in parallel rows as in machine tufting or weaving. The back of a completed, hand-tufted custom rug is coated with latex. The surface of the rug is finished by one of the following processes: • Tip-sheared rugs are produced by cutting random loops that project beyond the surface of the rug. This process adds texture and visual interest to the level finished surface of the rug. • Cut-and-loop rugs are continuously tufted like single-pile rugs. Those portions of the rug surface that will be cut pile are tufted in a deeper pile height and then cut down to the height of the loop surface. • Carved rugs incorporate three-dimensional designs into the rug surface. After the tufting process is complete, electrically operated shears are used to cut patterns in the rug surface. Nonrectilinear shapes are possible with hand-tufted rugs. Unlike tufted or woven carpets, custom shapes and edge configurations are available. Hand-tufted rugs are often used in circular or other nonrectilinear applications and on spiral stair treads, where each tread carpet is different. An unlimited number of colors is possible, and intricate custom designs are often incorporated. HAND-TUFTED CARPET 7.423 WOOL CARPET PILE WEIGHT DENSITY 7.422 TYPE OF TRAFFIC AMOUNT OF TRAFFIC LOCATION PILE WEIGHT DENSITY PROJECTED LIFE EXPECTANCY Light Up to 1,500 passages/week (250/day) Hotel guest rooms, private offices, small meeting rooms 80 to 114 5 to 7 years Medium 1,500 to 5,000 passages/week (250–750/day) Hotel guest corridors, conference rooms, shops, larger offices 115 to 149 5 to 7 years Heavy 5,000 to 15,000 passages/week (750–2,500/day) Restaurants, larger function rooms, open-plan offices, large shops, hotel main corridors 150 to 199 5 to 7 years Very heavy 15,000+ passages/week (2,500+/day) Hotel lobbies, office entrance areas, department stores (ground floor), cash register counters, bars 200+ 5 to 7 years Source: Soroush Custom Rugs, Kensington, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 208 I N T E R IO R CO NST RU CTION Page 208 INTERIOR F INISHES HAND-TUFTED CARPET SPECIFICATIONS 7.424 TYPE OF SPACE TYPICAL APPLICATIONS PILE CONTENT FACE WEIGHT TOTAL WEIGHT PILE HEIGHT TOTAL THICKNESS Wool has been used for centuries in the manufacturing of carpet, and is still the standard against which other carpet fibers are judged. It is generally the most expensive carpet fiber and is commonly used in woven carpets. When exposed to flame, wool chars, rather than melting like most synthetic fibers, making it naturally flame resistant. It dyes well and has good resistance to soil and wear. The outer layer of a wool fiber is scaly, which diffuses light, thus hiding soil. The inner core is composed of long, rounded cells that provide the elasticity essential for excellent appearance retention. High-traffic public and residential spaces Standard-traffic lobbies, boardrooms, meeting rooms, bar areas, club rooms, royal and presidential hotel suites, grand staircases 100% semiworsted wool 56 oz/yd (2 kg/m) ±105 oz/yd (3.8 kg/m) 15/64 (6 mm) 5/16 (7.9 mm) Very high traffic public spaces Busy hotel lobbies, casinos, reception areas, lounge areas, ballrooms, main corridors in luxury facilities, business service areas in hospitality facilities, grand staircases 100% semiworsted wool 72 oz/yd (2.5 kg/m) ±125 oz/yd (4.4 kg/m) 16/64 (6.4 mm) 25/64 (9.9 mm) Sisal is a strong, woody fiber produced from the leaves of the agave plant, which is found in Central America, the West Indies, and Africa. Used mostly in twine and rope, it has become a popular contemporary flooring fiber. Extremely heavy traffic public spaces Hotel lobbies that also function as casino entrances, main promenade areas 100% semiworsted wool 88 oz/yd (3.1 kg/m) ±140 oz/yd (5 kg/m) 16/64 (6.4 mm) 23/64 (9.1 mm) WOOL AND NYLON FIBERS 7.426 Source: Soroush Custom Rugs, Kensington, Maryland. CARPET FIBERS A fiber is the fine, hairlike strand that forms the basis of a yarn. Fibers are found in nature or are manufactured (synthetic) and are categorized by their length as either staple or filament. CARPET YARN PLIES 7.425 • Staple fibers are short, typically measured in centimeters or inches. All natural fibers except silk are staple fibers. • Filament fibers are long and continuous. Because synthetic fibers are produced by extruding chemical solutions through a device that resembles a showerhead called a spinerette, they are filament fibers. However, they can be cut to staple fiber lengths. Yarns are formed by twisting fibers together to create a continuous strand. Yarns are classified in two types: spun and filament. Spun yarns are composed of staple fibers twisted together. Filament yarns are composed of continuous strands made from either a spinerette-generated synthetic fiber or from silk. Bulked continuous filament (BCF) yarns are continuous strands of synthetic fiber that are formed into yarn bundles without the need for spinning, which is required for all natural and staple synthetic fibers. BCF generally offers better wear, but staple fibers provide the much-sought-after wool-like appearance. YARN DESIGNATIONS Yarn designations express the relationship between length and weight. The denier system is used for filament yarns; the yarn count system is used for spun yarns. Ply is the number of single strands of spun yarn twisted together to form the yarn. Ply is not a measure of quality, but will affect the appearance of a carpet. Higher-ply counts give a coarser, nubbier texture. Denier is a unit of yarn measurement equal to the weight in grams of 9,000 meters of the yarn. The higher the denier, the heavier the yarn and generally the better the strength, resiliency, and abrasion resistance. Heavier-filament yarns are designated by higher denier numbers. For example, a 15-denier yarn would be suitable for sheer hosiery; a 2,200-denier yarn would be suitable for carpet. Yarn count is a system similar to the gauge of a spun yarn’s weight. Heavier yarns are designated by lower yarn count numbers. For example, a 70-count yarn is quite fine, whereas a 10-count yarn is thick and heavy. PILE TYPES Pile consists of yarns or fibers projecting from a substrate, acting as a wear surface. The selection of a pile type depends on the desired visual effect and performance expectations. CARPET FIBER TYPES Acrylic was one of the first synthetic fibers to be used successfully in the production of carpet. However, because the color and texture of acrylic fiber can be glossy and harsh, and because acrylic carpet pile crushes easily, it is no longer recommended for use as a commercial carpet fiber. Nylon is the most popular carpet fiber. Nylon has excellent wearability, abrasion resistance, and resilience; solution-dyed nylon is also resistant to harsh cleaning chemicals and sunlight fading. However, because of nylon’s excellent durability, appearance retention is a concern. Long before a nylon carpet wears out, its appearance can be permanently ruined. Nylon is extruded through a spinerette. Nylon fibers are smooth and tend to be reflective or shiny. Nylon 6.6 has a melting point of 493°F, high for a synthetic fiber, though not a match for polyesters or aramids. This fact makes it the most resistant to heat and friction and enables it to withstand heat setting for twist retention. Its long molecular chain results in more sites for hydrogen bonds, creating chemical “springs” and making it very resilient. It has a dense structure with small, evenly spaced pores. This means that nylon 6.6 is difficult to dye, but once dyed it has superior colorfastness and is less susceptible to fading from sunlight and ozone and to yellowing from nitrous oxide. Polypropylene is the lightest commercial carpet fiber. Polypropylenes are known for their excellent stain and mildew resistance, low moisture absorbency, excellent colorfastness in sunlight, and high strength. They also minimize static electricity. Olefin is a polypropylene. Polypropylene is commonly used in outdoor carpeting. Polyester fibers are known for their color clarity and their capability to retain color. More popular for residential carpet applications than for commercial uses, polyester has a luxurious feel. • Cut pile yarns are at the same height. Durability depends on the type of fiber used, the density of the tufts, and the amount of twist in the yarn. • Uncut pile yarns are at the same height. Level loop pile has a pebbled surface texture that hides footprints and chair caster marks, and is durable in high-traffic areas. • Cut-and-loop pile combines cut and looped yarns to provide varied surface textures and sculptural effects. Cut-and-loop pile type requires 100% latex penetration. Cut-and-loop pile with more than 50% cut surface should meet cut pile guidelines. • Random tip-sheared yarn produces contrasts between cut and uncut loops of varying heights. • Velvet or plush has a smooth cut pile. Yarn ends blend together for a consistent surface appearance. This pile type shows footprints and shading marks. Textured plush helps hide footprints and vacuum marks. • Saxony is similar to velvet pile but has twisted yarn, which gives definition to each tuft. The loops are cut during the construction process. Saxonies are made with heat-set yarn, usually in a dense, low-pile construction. This pile type shows footprints and shading marks. • Multilevel (patterned) loop uses uncut pile yarns at varying heights. • Frieze (pronounced free-zay) is a tightly twisted, heat-set yarn that hides dirt well. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 209 INTERIOR F INISHES INTE R I O R CO N ST RU CT I O N 209 CARPET DENSITY PILE TYPES 7.427 Density, the amount of pile yarn per unit volume of carpet, is influenced by gauge (stitches per inch across the width), yarn size or thickness, and pile height. A larger yarn can be tufted at a wider gauge and receive the same density as a fine yarn at a small gauge. For areas where heavy foot traffic is likely, a density of 5,000 to 7,000 or more may be necessary. Office spaces with moderate traffic require a density of 4,000 to 6,000. Because of the fundamental differences in the manufacturing processes, different terms are used to describe carpet density for each type of carpet construction. CARPET TRAFFIC CLASS RECOMMENDATIONS 7.430 AREA TRAFFIC CLASS TYPE OF SPACE Airports Administrative offices Banks I Corridors/all public and ticket areas III Executive offices I Lobbies II to III Corridors II to III Teller windows III II to III DENSITY MEASUREMENTS FOR TUFTED CARPET Gauge is used for the widthwise density measurement of tufted Convention centers Auditoriums Corridors and lobbies III carpet. It is the measure of the spacing of the tufting needles, center to center, across the width of the carpet. Gauge is measured in fractions of an inch. For example, 1/8 gauge means that the tufting needles are spaced 1/8 in. (3 mm) apart, producing eight yarn ends per inch. Places of worship Churches, synagogues, and mosques I to II Meeting rooms II Stitches define the lengthwise density measurement of tufted carpet. They measure the number of ends tufted by the needles down the length of the carpet. Generally, the number of stitches per inch and the number of needles per inch are approximately the same. Pile height is the length of a tuft from the backing surface to the tip of the tuft. It is measured in fractions of an inch. Although a deep pile may provide a more luxurious feel underfoot, it also has a greater tendency to crush and show wear. Lobbies II to III Golf clubs Locker rooms and pro shops III Other areas II to III Healthcare facilities Executive and administrative offices I to II Hotels, motels, and apartments Patient rooms and lounges II Lobbies, corridors, and nurses’ stations III Rooms I Corridors II Lobbies III Libraries, museums, and art galleries Administrative offices I Public areas II to III is the number of ends in a 27-in. (685-mm) width of carpet. A yarn loop in the surface of a carpet is referred to as an end. The pitch can be divided by 27 to compare widthwise density with that of a tufted carpet. For example, if the pitch is 216, it is divided by 27, which equals eight ends per inch, or 1/8 gauge in a tufted carpet. Office buildings Executive or private offices I Clerical areas II To convert gauge to pitch, multiply needles (ends) per inch by 27; for example, 1/10 gauge is equivalent to 270 pitch, or 10 ends per inch 27; 1/8 gauge is 8 ends of yarn per inch 27 = 216 pitch. DENSITY MEASUREMENTS FOR WOVEN CARPET Pitch is used to measure the widthwise density of woven carpet. It The terms rows in Axminster and wires in Wilton and velvet carpets refer to the number of ends per inch lengthwise. In woven carpet, the pile height is referred to as the wire height, referring to the height of the steel blades in the loom on which the tufts are formed. Wire height is stated in decimals of an inch. Corridors II to III Cafeteria III Restaurants Dining areas and lobbies III Retail stores Windows and display areas I Minor aisles, boutiques, and specialized departments II Schools and colleges Major aisles, checkouts, supermarkets, etc. III Administrative offices I Classrooms and dormitories II Corridors and cafeteria III Source: BASF, Dalton, Georgia. CARPET TRAFFIC CLASSIFICATION 7.429 CLASS TRAFFIC WALK-ONS PER DAY I Light Up to 500 Areas that undergo a limited amount of traffic and where there is some soiling Executive offices, hotel bedrooms II Heavy 500 to 1,000 Areas that undergo frequent traffic flowing in the same direction and where there is heavy dirt, grit, twisting, turning, and spillage Hotel corridors, auditoriums, school classrooms III Extra heavy More than 1,000 Areas that are subject to extremely frequent and concentrated traffic flowing in the same direction and where there is severe dirt, grit, twisting, turning, heavy rolling, and spillage Airports, bank teller window areas CLASS I Level loop EXAMPLES Source: BASF, Dalton, Georgia. CARPET DENSITY GUIDELINES 7.428 PILE TYPE DESCRIPTION CLASS II CLASS III WEIGHT DENSITY WEIGHT DENSITY WEIGHT 16 oz/sq yd (0.6 kg/sq m) 3,600 oz/cu yd (2,772 kg/cu m) 20 oz/sq yd (0.7 kg/sq m) 4,200 oz/cu yd (3,234 kg/cu m) 24 oz/sq yd (0.8 kg/sq m) DENSITY 4,800 oz/cu yd (3,696 kg/cu m) Cut loop 20 oz/sq yd (0.7 kg/sq m) 3,600 oz/cu yd (2,772 kg/cu m) 24 oz/sq yd (0.8 kg/sq m) 4,200 oz/cu yd (3,234 kg/cu m) 28 oz/sq yd (1 kg/sq m) 4,800 oz/cu yd (3,696 kg/cu m) Cut pile, not heat set 28 oz/sq yd (1 kg/sq m) 3,800 oz/cu yd (2,926 kg/cu m) 33 oz/sq yd (1.1 kg/sq m) 4,500 oz/cu yd (3,465 kg/cu m) 38 oz/sq yd (1.3 kg/sq m) 5,000 oz/cu yd (3,850 kg/cu m) Cut pile, heat set 28 oz/sq yd (1 kg/sq m) 3,800 oz/cu yd (2,926 kg/cu m) 35 oz/sq yd (1.2 kg/sq m) 4,500 oz/cu yd (3,465 kg/cu m) 43 oz/sq yd (1.4 kg/sq m) 5,000 oz/cu yd (3,850 kg/cu m) Source: BASF, Dalton, Georgia. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 210 I N T E R IO R CO NST RU CTION NEEDLES (ENDS) PER INCH INTERIOR F INISHES CARPET INSTALLATION CARPET GAUGE OR PITCH 7.431 GAUGE Page 210 PITCH 3/8 2.7 1/4 4 73 108 3/16 5.3 144 5/32 6.4 173 1/8 8 216 1/10 10 270 5/64 12.8 346 1/16 16 432 1/20 20 540 1/25 25 675 CARPET PERFORMANCE Wear resistance of a carpet, like that of other textiles, is affected by many factors, such as the face and total weight, pile density, type and length of the fiber, structure of the yarn, and the construction of the carpet. Face weight, also referred to as pile weight or yarn weight, is the weight of the pile yarn in ounces per square yard of carpet. It does not include the weight of the backings or coating. The face weight describes the amount of yarn in the wear surface of the carpet. Total weight, or finished weight, includes the face weight and the weight of backing materials, finishes, and coatings. It is expressed in ounces per square yard of carpet. Total weight is less an indication of quality than is face weight. Pile density is the weight of pile yarn in a given volume of carpet face. It is determined by the number and size of the carpet tufts. Pile density is the most important selection factor in high-traffic installations. For example, nylon is a very durable fiber; however, if the pile density of a nylon carpet is too low, crushing can occur; and although the nylon may succeed in performance, it can fail in appearance. Average pile density is determined by the following formula: There are two types of carpet installation: stretch-in and adhesive. For broadloom carpet, there are three types of adhesive installation: direct glue-down, double glue-down, and the newest installation type, self-stick. Releasable adhesives can facilitate carpet repair or replacement. STRETCH-IN INSTALLATION Stretch-in installation is the traditional method of carpet installation, whereby the carpet is stretched over a cushion and attached at the perimeter with a tack strip. This is the most common installation method for residential applications and is used commercially for woven wool carpets and in areas where underfoot comfort and luxury are required (e.g., hotel lobbies and boardrooms). Stretch-in applications allow for easy removal and replacement of the carpet and cushion. Because stretch-in carpet is secured only around the perimeter, such installations can ripple, causing accessibility problems; hence, they may not be appropriate for large areas and heavy commercial or rolling traffic. ADHESIVE INSTALLATION Direct glue-down installation is the most common method of commercial installation. It is economical and practical. The carpet is glued directly to the floor without a cushion. This is the most dimensionally stable installation method and is often required for stair or ramp applications, even if different installation methods are specified for other areas of the project. Proper substrate conditions are imperative for a successful glue-down installation. Uneven substrates can cause irregular wear patterns. Double glue-down installation combines the underfoot comfort of stretch-in installation with the stability of the direct glue-down method. The carpet cushion is adhered to the floor, and then the carpet is glued to the cushion. Self-stick installation involves applying a flexible adhesive layer to the carpet backing, which is then covered with a protective plastic film until installation. The labor involved in adhesive application and the time required to ensure the proper tackiness are eliminated. This type of carpet type typically comes in smaller widths, about 6 ft (1.8 m), for ease of manipulation during layout and installation. CARPET TILE INSTALLATION Carpet tiles can be applied over a variety of substrates, including plywood, particleboard, and hardwood. They can be installed over concrete that meets the manufacturer’s standards for moisture vapor emissions and pH levels; highly porous concrete subfloors may need to be sealed. Metal surfaces should be cleaned of dirt, grease, and debris. Terrazzo, ceramic, marble, and slate floors should have all cracks and irregularities filled before installation of carpet tiles. Manufacturers do not recommend glue-down installation over sheet vinyl, laminated solid vinyl, or rubber flooring or over some types of previously applied adhesives, unless all finishes or adhesives are first removed. There are four methods of carpet tile installation: free-lay, fullglue, tack tiles, and self-stick. • Free-lay installations involve applying a strip of adhesive about every 15 ft (4.5 m) and around the room perimeter. Tiles in those areas are anchored in place, and neighboring tiles are butted snugly against each other. • Full-glue installations should be specified where heavy or wheeled traffic is anticipated. In this case, tiles are typically installed with a “stair-step” technique. The installation grows from the center of the room. • Tack tiles are glue-free adhesive squares with very low VOC levels and no odor. They allow tiles to be attached to each other rather than to the floor, creating a floating carpet tile surface. • Self-stick installation is used when a tile has a preapplied pressure-sensitive adhesive coating covered with a protective plastic film. CARPET INSTALLATION COMPARISON 7.432 STRETCH-IN DIRECT GLUE-DOWN DIRECT GLUE-DOWN WITH ATTACHED CUSHION DOUBLE GLUE-DOWN 36 W (oz/sq yd) D (oz/cu yd) = T (in.) Patterned carpet is easier to match. D (oz/cu yd) ÷ 26,944.67 = g/cu cm More resilient than direct glue-down. Labor is usually less expensive. Increased delamination strength Improved carpet appearance and improved edge ravel resistance. retention, comfort underfoot, and overall performance. Extends carpet life. Suitable for rolling traffic and ramp areas. Effective moisture barrier. Carpet bordering and inlay simplified. Less crushing and packing of pile. Seams are more durable because there is no vertical flex. Improved thermal and acoustical contribution. Suitable for wheeled traffic area. Adds insulation value (R-value). Unrestricted as to size of area. Elimination of second adhesive requirement. Size of installation area is not restricted. Higher sound absorbency (NRC) values. No restretch situations. Responds better to vacuuming. Facilitates access to electrical and telephone lines under the floor. where D is the density, W is the pile yarn weight, and T is the pile height or thickness. Pile yarn is the most expensive component in carpet manufacturing. For a given weight, a lower pile height and a higher pile density provide the greatest performance value. Abrasion resistance is sometimes used as a relative measure of a carpet's durability. Because modern synthetic fibers are highly resistant to abrasive wear, wear resistance is not tested for as often as appearance retention. Appearance retention tests aim to simulate floor traffic with mechanical devices. Pile appearance changes due to wear are commonly tested by either of two methods: the hexapod tumbler test or the Vettermann drum test. Static control, the electrostatic discharge properties of carpet, may need to be considered where sensitive electronic or computer equipment is in use. Static electricity is created by the friction of rubbing materials together—for example, the sole of a shoe and carpet fiber. Static electricity does not become apparent until the relative humidity drops below 40%. There are two methods for enhancing the electrostatic discharge properties of carpet: the incorporation of a conductive filament, typically carbon-loaded nylon, or the application of topical treatments. Contributors: Carpet and Rug Institute, Dalton, Georgia. Jennie Harden, Gensler, Dallas, Texas. Cushion cost is eliminated. Can be used over floors that may be Seam peaking is practically unacceptable for direct glue-down. eliminated. Removal usually costs less than removal of a direct glue-down installation. Buckling is minimized in buildings that have heat and air conditioning turned off for extended periods, such as schools, churches, and theaters. Corrective measures, such as seam repair, are easier to perform. Intricate border and inlay capabilities. Improved appearance retention and foot comfort. Combines cushioning benefits of a separate cushion and of stretch-in installation. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 211 INTERIOR F INISHES CARPET COLORING METHODS NOISE TRANSMISSION Carpet coloring is accomplished by predyeing the carpet fibers before the carpet is manufactured, or postdyeing the finished piece of carpet. Most carpet is postdyed, because this process allows manufacturers to respond quickly to the needs of the market. The INR represents the sound insulation provided by a floor-ceiling assembly from an impact noise. Sound levels are measured in an isolated room below. The data is related to a minimum standard of 0 INR. Assembly ratings less than 0 are considered unsatisfactory. Assembly ratings that are greater than 0 are deemed superior. PREDYEING METHODS There are two major predyeing methods: solution dyeing and yarn dyeing. Solution dyeing is commonly preferred in areas subject to sunlight fading or spills, because the color is integral to the fiber. The dye is combined with the fiber chemicals before the extrusion process. The color of solution-dyed yarn is consistent throughout the fiber. Solution-dyed yarns have excellent colorfastness qualities against both sunlight and crocking, and can withstand cleaning with harsh chemicals. Polyester, polypropylene, and nylon are commonly solution dyed. Solution-dyed yarn holds a large share of the commercial market but only a small portion of the residential market. Yarn-dyeing methods involve either space dyeing, which is used to apply multiple colors to the yarn before it is made into carpet, or solid-color yarn dyeing. POSTDYEING METHODS With postdyeing methods, the carpet is dyed after the carpet has been tufted onto its primary backing, and before a secondary backing has been attached. Common techniques include: Beck or piece dyeing involves sewing batches of carpet into a loop that is hung on a large reel inside a dye beck unit. The unit moves the carpet through the dye liquid for a set period of time. This results in excellent uniform color throughout the carpet. Continuous solid-color dyeing can be used to create an almost unlimited length of 12 ft (3.7 m) wide carpet from pieces sewn end to end. Printing: Patterns can be applied to carpet after the finishing process. Printed carpet simulates the intricate patterns of woven carpet at a much lower cost. Common techniques for carpet include screen printing and jet printing. ACOUSTICAL CONSIDERATIONS Carpet is an important component of open office space because of its sound-deadening properties. Although ceiling surfaces are the most effective at absorbing office speech sounds, sound produced by furniture movement and floor impacts can effectively be absorbed by the proper selection of carpet and carpet cushion. In hotels, carpeted guest rooms significantly reduce sound transmission to the rooms below. In churches and theaters, the noise generated by latecomers can be lessened without altering the carefully engineered acoustics of the space. In critical spaces such as open-plan offices, broadcast studios, and theaters, the full details of impact insulation properties and noise absorption characteristics should be considered. One of carpet’s most important contributions to the appeal of a space is its acoustical properties. The acoustical properties of carpet are measured in three ways: • Noise reduction coefficient (NRC) • Impact noise rating (INR) • Impact insulation class (IIC) In tests of carpet without cushion, greater pile weights were correlated with higher INR ratings. Cut pile carpets are somewhat more effective in absorbing sound than loop piles. The fiber content of the carpet has little effect on its capability to absorb sound. SOUND ABSORPTION The NRC is the average of four absorption coefficients measured at frequencies from low- to high-pitched sounds and rounded off to the closest 5%. The NRC is determined by ASTM C 423, Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method. The NRC is used in calculating the required amount of sound-absorbing material and can be used to compare the sound absorption qualities of one material with another. The higher the NRC, the greater is the sound absorption. The IIC also measures the sound insulation of a floor-ceiling assembly, but the IIC differs from the INR, not in the test procedure, but in the numerical scale applied. IIC rates floor-ceiling assemblies with positive numbers only in ascending order of efficiency. The higher the value, the less is the noise transmitted. An IIC value can be estimated by adding 51 to the INR value. THERMAL CONSIDERATIONS Carpet contributes to the thermal insulation of a space. The total Rvalue of a carpet is more dependent on the total thickness of the carpet than the fiber content. When the carpet R-value is not available, multiply the total carpet thickness measured in inches by a factor of 2.6 to approximate the carpet’s R-value. R-values can be considered additive for any combination of materials. For example, a combination of carpet with an R-value of 1.3 and a prime polyurethane cushion with an R-value of 1.6 will yield an overall R-value of 2.9. INDOOR AIR QUALITY Since the 1990s, the carpet industry has actively sought to reduce chemicals used in carpeting products that might cause health problems. Chemicals used to produce some carpet backings, such as synthetic latex resin, do have documented health and environmental problems. There is a wide variation in carpet emissions for latex-bonded carpets, including wool carpets. Fusion-bonded and CARPET TRANSITION DETAILS 7.433 INTE R I O R CO N ST RU CT I O N 211 needle-punched carpets that do not use SB latex backings may be worth considering. The Carpet and Rug Institute (CRI) offers Green Label and Green Label Plus testing and certification to indicate carpet, cushions, and adhesives that emit low VOCs. The already low VOC emission level of new carpet drops significantly after 24 hours, even sooner with fresh air ventilation. Once installed, carpets can contribute to indoor air quality problems while in use. Carpet fibers can collect chemicals and dirt from outside the building; regular vacuuming is required, although not all contaminants will necessarily be removed. Dust mites readily live in carpets. Carpet fibers also trap VOCs, and can re-emit them later. Wet carpet is an effective growth medium for mold and mildew. CARPET TRANSITION DETAILS The transition from one flooring material to another affects accessibility and occupant safety. Changes in materials, such as from carpet to ceramic tile or stone, may involve different flooring heights. Even carpet-to-carpet transitions can create uneven surfaces. The edges of carpet on finish floor surfaces require special consideration to avoid fraying. Thresholds, where used, must be able to transition between varying heights. CARPET CUSHION Carpet cushion can significantly extend the life of a carpet. Environmental conditions, anticipated traffic, and desired feel underfoot should be considered in the selection of a carpet cushion. Carpet cushions can be categorized as three types: felted fiber, sponge rubber, and polyurethane foam. Felted fiber cushions are made by needle punching natural fiber, synthetic fiber, or a combination of the two, into a feltlike pad. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 212 I N T E R IO R CO NST RU CTION Antimicrobial treatments are recommended for natural-fiber pads because they are susceptible to mold and mildew. Fiber cushions tend to have a firm feel underfoot. Over time, felted-fiber cushions may be crushed under heavy wear. Sponge rubber: Unlike felted-fiber cushions, rubber cushions are highly compressible. Reinforced foam rubber has a smaller cell structure than sponge rubber, thus providing more uniform support. Sponge rubber cushions are generally open-cell foams, which are less resilient than closed-cell foams. Carpet with a sponge rubber cushion surpassed other cushions when tested for INR scores. Polyurethane foam: The chemical compositions of polyurethane foam (also called foam rubber) carpet cushions are similar, but their different cellular structures affect their performance. Bonded polyurethane foam (or rebond, as it is sometimes called) is manufactured from scraps of foam bonded together through an adhesive and heat fusion process. Modified prime polyurethane foam is manufactured in a continuous sheet and, unlike densified foam, may contain fillers. Densified foam is denser than modified prime foam and is highly resistant to bottoming out. Rubber pad made from recycled tire rubber that is dense and durable may be available. Residential carpet cushion Class 1 is intended for light and moderate traffic such as living and dining rooms, bedrooms, and recreational rooms. Class 2 cushions may be used in Class 1 applications. Class 2 is designed for heavy-duty traffic, such as lobbies and corridors in multifamily facilities, and all stair applications. The maximum thickness for any product is 0.5 in. (13 mm). CARPET RECLAMATION AND END-OFLIFE MANAGEMENT Perhaps the greatest carpet-related environmental problem is the amount of old carpet that ends up in landfills each year. Carpet manufacturers are addressing this problem by recycling old carpet materials back into carpet production, recycling old carpet into alternative products such as building material and auto parts, refurbishing old carpet into new carpet tiles, and reclaiming old carpet so it can be reused or recycled. CARPET REUSE Aside from continuing to use existing carpet, the highest environmental recovery possible for used carpet is reuse. Some manufacturers pick up and return used carpet to their manufacturing facility for aggressive cleaning, rebulking, and, in some cases, redyeing in a new pattern. CARPET RECYCLING A second alternative to landfill disposal is recycling. It costs money to pick up old carpet, identify its face fiber, break the carpet down into its components, convert these into new product, and transport them to a manufacturing location. Companies providing carpet recycling services charge money to cover investment of capital, salaries, maintenance costs, energy costs, and other expenses. Pricing for recycling services depends on current fuel charges, material types, and the stage of processing, and vary with location and available services. The most common type of carpet in the United States today is tufted carpet with latex backing. Carpet recycling involves identifying the face fiber (the most valuable part of the carpet); for tufted carpet, this is typically nylon 6.6, nylon 6, polypropylene (olefin), or polyester. The face fiber makes up approximately half of the weight of the carpet, although this varies with its construction. The backing system is typically latex (used for most residential carpet) or PVC (most common in commercial carpet). Additional layers are typically polypropylene, with calcium carbonate used as an inert filler. The recycling of used carpet components into new carpet is the highest level of carpet recycling. It is difficult and costly to produce new carpet from old carpet. Face fibers can sometimes be shredded and heated to extract raw materials, which can be purified for use in new yarn. Backings may be reused as components of new backing materials. Contributors: Jennie Harden, Gensler, Dallas, Texas. Steven R. Breuer, AIA, LEED AP, lauckgroup, Dallas, Texas. Kim McGhee and Lilliana Romerz, Boston Architectural Center, Boston, Massachusetts. Page 212 INTERIOR F INISHES CARPET MATERIALS ACCEPTED FOR RECYCLING AND ENERGY PRODUCTION 7.434 RECYCLING Nylon 6 carpet Some vinyl-backed carpet tiles Foam pad/rebond ENERGY GENERATION NOT ACCEPTABLE (OR ADDITIONAL CHARGE) Nylon 6.6 carpet and mixtures Polypropylene carpet Polyethylene terephthalate (PET) carpet Jute-backed carpet Cushion- or foam-backed carpet Wet material Carpet contaminated with construction debris (asbestos, gypsum board) or trash Wool fiber Jute padding Rubber-backed carpet and rubber pad Excessively glued carpet Double-stick carpet and pad Tack strips and metal trim Most of the carpet that is recycled is downcycled into products such as composite lumber decking and sheets, tile backer board, roofing shingles, railroad ties, plastic automotive parts, and stepping stones. Other products include reusable hay for sediment control on construction sites, sewage pipes, and concrete additives. Some is recycled into carpet cushion. ENERGY PRODUCTION The final alternative for keeping used carpet out of landfills is incineration in industrial boilers. Burning the petroleum-based materials in carpet for energy produces more energy and fewer of some types of emissions than coal. However, this method does have significant environmental drawbacks, and removes the materials from the sustainable stream. INDUSTRIAL WASTE Although more efficient manufacturing is reducing excess carpet waste, such as selvedges, trimmings, and shearings, the industry has found creative uses for carpet by-products, such as carpet trim and yarn scraps, to avoid the use of local landfills. These include the following: • Fiber and yarn that cannot be reused in manufacturing are recovered for use in other products. • Excess carpet is cut into rugs and mats and sold for other uses. • Waste carpet trimmings, backing, and yarn often are sold to recycling plants to be processed into such items as carpet cushion, furniture batting and cushions, reinforcing filler for concrete, fence posts, road underlayment, plastic lumber, and automotive parts. • Polyethylene packaging, used to wrap carpet yarn spools and other raw material, is recycled into plastic pellets to be sold to extruders of film, plastic wrap, or plastic trash bags, or it is used in molded items. • Other materials used in the manufacturing process, such as cardboard, paper, aluminum, wooden pallets, yarn cones, roll cores, liquid containers, raw material packaging, and scrap metal, are either reused or recycled. LIFE CYCLE ASSESSMENT Life cycle assessment (LCA) strives to compare the full range of environmental and social damages assignable to products and services, to be able to choose the least burdensome one. LCA succeeds in accurately measuring the impacts of the technology used for delivering products, but not the whole impact of making the economic choice of using it. Life cycle assessment looks at raw material production, manufacture, distribution, use, and disposal, and includes transportation. It can be used to evaluate the environmental performance of a single product or of a company. Common concerns evaluated include greenhouse gases, acid rain, smog, and ozone layer depletion, toxicity, habitat destruction and land use, and depletion of minerals and fossil fuels. WALK-OFF SYSTEMS AND MATS Employing a walk-off system at all high-volume building entrances provides a way to stop soil and contaminants from entering the building via its occupants and visitors. The entry system should be at least 15 ft (4.6 m) long and as wide as the entry door. Most dirt from shoe soles is removed after the first five to six steps. Entry systems should be routinely cleaned to ensure good working conditions. Types of walk-off systems include roll-up mats and permanent grilles or grates. In addition to recessed assemblies, a variety of surface-applied entrance mat systems are available. These include both roll-up and permanently installed mats that are either modular or customized to fit entrance spaces. ROLL-UP MATS Mats are a cost-effective way to ensure that dirt and moisture from footsteps are removed at the entrance. Different types of mats brush soil from shoes and can hold large amounts of dirt; absorbent mats can prevent moisture from being tracked into the building. These mats should be vacuumed daily in the heaviest-traffic areas and as infrequently as weekly in light-traffic areas. Most mats contain recycled content. PERMANENT WALK-OFF GRILLES OR GRATES Floor grille and grating systems, available in a wide range of styles, are used in an increasing variety of building applications. A recessed built-in system is a more permanent way to catch and hold dirt particles, providing protection at the building entrance. • Recessed systems are generally less than 1 in. (25 mm) deep. • Shallow pit systems are 1 to 3 in. (25 to 76 mm) deep. • Deep pit systems are more than 3 in. (76 mm) deep. A typical grille or grate system is made up of a series of interlocking rails that run perpendicular to the traffic direction. Types of tread surfaces include serrated aluminum, abrasive or nylon carpet, and rubber or vinyl filled. FLOOR MATS A wide range of interlocking resilient floor grid systems are available for wet and high-impact areas such as weight rooms, aerobics studios, and other athletic facilities, as well as kennels and stables. Systems are available for both indoor and outdoor applications. Increasingly, flooring construction is specialized to specific athletic applications; for example, air-supported martial arts flooring is available. In addition, individual removable mats ranging from 4 to 6 ft (1.2 to 1.8 m) wide are available in a variety of lengths for particular athletic applications. Flooring for wet areas is used in pool areas, locker rooms, roof play areas, and other locations where water flow to drainage systems must be maintained. Flooring for high-impact areas is used in weight rooms and for aerobics classes, indoor children’s play areas, and similar areas where impact or noise is an issue. Verify that floor mats and grid systems occurring on accessible routes or in areas required to be accessible meet the requirements for changes in level. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 213 INTERIOR F INISHES FLOORING FOR WET AREAS 7.435 CEILINGS Ceilings often conceal the underside of the floor or roof above, and may be part of a floor/ceiling assembly. The underside of a floor showing the supporting beams may be finished to form a beam ceiling. A cove (or coved ) ceiling has a concave surface at its edge, eliminating the interior angle between the wall and the ceiling. Coffered ceilings are made up of recessed panels that are usually square or octagonal. INTE R I O R CO N ST RU CT I O N 213 LIGHT COVE ACOUSTICAL CEILING TO DRYWALL CEILING/SOFFIT—SECTION 7.439 CEILING CONSTRUCTION WOOD CEILING CONSTRUCTION Ceilings can be framed on-site from 2 6 or 2 8 lumber resting on exterior and interior walls. Partitions should be located to take advantage of ceiling joists of 12, 14, 16 ft (3.7, 4.3, 4.9 m), or longer even lengths to span from exterior walls to load-bearing interior walls. FLOORING FOR HIGH-IMPACT AREAS 7.436 CEILING SOFFITS An interior soffit is a dropped section of a ceiling positioned along the walls. Soffits are useful to change ceiling heights; as transitions between ceiling materials; and to conceal lighting housings, ductwork, plumbing, and electrical conduit, and other equipment. SOFFIT GYPSUM BOARD CEILING—SECTION 7.438 RECESSED MAT SYSTEM 7.437 Source: Armstrong Ceiling Systems. ACOUSTICAL CEILING TO GYPSUM BOARD SOFFIT— SECTION 7.440 Source: Armstrong Ceiling Systems. Source: Armstrong Ceiling Systems. GYPSUM BOARD CEILING TO GYPSUM BOARD SOFFIT—SECTION 7.441 Source: Armstrong Ceiling Systems. Contributors: Jennie Harden, Gensler, Dallas, Texas. Brosso, Wilheim & McWilliams, Baltimore, Maryland. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 214 I N T E R IO R CO NST RU CTION Page 214 INTERIOR F INISHES PLASTER CEILINGS METAL LATH SUSPENDED FROM STEEL JOIST 7.442 FRAMING SYSTEMS SUSPENDED PLASTER CEILING DETAILS 7.443 The traditional framing system consists of main supports of 1-1/2 in. (38 mm) cold-rolled channels (CRCs) spaced at 4 ft (1.2 m) on center, with cross supports of 7/8 in. (22 mm) hat track spaced at 2 ft (0.6 m), on center, tied below the CRCs, installed at the desired height with hanger wire. The gypsum board is then screwed into the hat track. A gypsum board ceiling grid system is made up of main beams and cross tees that are suspended by hanger wire from the structure above at the desired height. Very similar to an acoustical ceiling panel grid, sections of the main beams lock together end to end while cross tees span between the main beams. The ends of the main beams and cross tees attach to the wall molding that runs around the perimeter of the space. The face dimension of both the main beams and the cross tees is 1-1/2 in. (38 mm), providing a large flange to screw the gypsum board panels into. Spacing of the main beams is typically 2 or 4 ft (0.6 or 1.2 m) on center, with the spacing of the cross tees at 2 ft (0.6 m) on center. GYPSUM BOARD ON CEILING SUSPENSION SYSTEM 7.444 PERIMETER DETAIL GYPSUM BOARD CEILINGS, COVES, AND SOFFITS Gypsum board ceilings, both flat and curved, have been constructed for decades using cold-rolled channels and hat track, all hung with hanger wire. Contributors: M. Kitty Myers, AIA, and Gabrielle Sapponara, Anshen & Allen Architects, San Francisco, California. James E. Phillips, AIA, Enwright Associates, Inc., Greenville, South Carolina. The Marmon Mok Partnership, San Antonio, Texas. Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 215 INTERIOR F INISHES TYPICAL GYPSUM BOARD VAULTED CEILING 7.445 INTE R I O R CO N ST RU CT I O N 215 COVE CEILING WITH CROWN MOLDING 7.447 Source: Armstrong Ceiling Systems. GYPSUM BOARD DOME 7.446 COVE CEILING WITH RETURN AIR GRILLE 7.448 Source: Armstrong Ceiling Systems. FINISHING The finishing of gypsum board ceilings or soffits will be the same using either the traditional framing system or the gypsum board grid system. Finishing ceilings utilizes the same process as walls, using joint compound at screw heads and using joint compound and joint tape at gypsum board joints. The process involves floating the joint compound smooth, applying additional coats after sufficient dry time, and, finally, lightly sanding to make smooth. Typically, ceilings are painted with a primer and two coats of flat paint. ACOUSTICAL SEPARATION When gypsum board is used as a ceiling, it works well as a sound barrier to airborne sound transmission, and will have a relatively high ceiling attenuation class (CAC) rating. It does not absorb sounds very well, so it will have a low noise reduction coefficient (NRC) rating. COVE CEILING LIGHT SOURCES Light sources available for light coves are strip fluorescent, cold cathode, neon, light-emitting diode (LED), and fiber optics. Contributor: Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. COVE CEILING WITH RETURN AIR SLOT 7.449 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 216 I N T E R IO R CO NST RU CTION CURVED COVE CEILING WITH LIGHT FIXTURE 7.450 Page 216 INTERIOR F INISHES ROOM ACOUSTICS ACOUSTICAL TILE CEILINGS Ceilings are often the largest sound-absorbing or sound-reflecting surface in an interior space. The sound quality in a room is a combination of the sound absorbed and the sound reflected by materials in the room. Sound absorption is measured in sabins. Acoustical tile ceilings are also known as concealed spline ceilings or concealed ceiling suspension systems. The concealed ceiling suspension system consists of a supporting grid that is completely concealed, and mineral fiber acoustical tiles that provide a monolithic, uninterrupted ceiling plane, with up to 50% access to the plenum. Acoustical ceiling tiles can also be installed directly to a substrate with adhesives or staples. Because most materials absorb more high-frequency sound waves than low-frequency ones, it is typical to find more sabins in a room at high frequencies than at low frequencies. In general, sound energy that is not absorbed will be reflected; thus, surfaces with low coefficients of absorption can be used to encourage sound reflection when appropriate. Distance and time comprise the two properties of sound. Indoors, sound waves reflect off surrounding surfaces, building up energy so sound drops off less quickly over distance or time than it does outdoors. The reflecting sound energy in a room reaches a constant level as a function of the sound-absorbing units (sabins) in the room. Indoors, sound energy lingers; this decay is called reverberation. The reverberation time (RT) is defined as the length of time, in seconds, it takes for sound to decay by 60 dB. Reverberation time is directly proportional to the volume of a space and inversely proportional to the units of absorption (sabins) in it. Shorter reverberation times greatly enhance speech intelligibility and are imperative in listening environments for people with hearing impairments and for rooms with live microphones for teleconferencing. INDOOR SOUND PATTERNS 7.453 LIGHT COVE ACOUSTICAL CEILING TO DRYWALL CEILING/SOFFIT 7.451 Acoustical ceiling suspension systems are made of bent steel with galvanized or painted finishes. Concealed tongue-and-groove, concealed Z, and concealed access styles are all available for 12 by 12 in. (305 by 305 mm) acoustical tiles that are fire rated. ACOUSTICAL TILES AND ACOUSTICAL PANELS Acoustical tiles are not designed to be easily removed without damage to the tile. They tend to be found in older and less styleconscious installations, and offer fewer size and finish options than acoustical panels. While acoustical tile installations provide a monolithic ceiling surface, installation can be more costly, and maintenance of the ceiling tile is more difficult than with acoustical panel ceilings. An acoustical tile ceiling is not as easily accessible to above-ceiling areas as acoustical panel ceilings with lay-in units. If access to the space above is not an issue, an acoustical tile ceiling is an option when the aesthetics and other conditions of the installation are appropriate for the project. Acoustical tiles are typically 12 by 12 in. (305 by 305 mm) with a thickness of 1/2, 5/8, or 3/4 in. (13, 16, or 19 mm). Acoustical panels are generally larger than acoustical tiles, and are installed in exposed or semi-concealed ceiling grids. Design considerations include fire resistance, high light reflectance, durability, seismic conditions, humidity/sag resistance, antimicrobial resistance, acoustical properties, and color. Volatile organic compound (VOC) emissions, recycled content, and LEED credits are all characteristics to consider when selecting an acoustical tile ceiling that meets sustainable design goals. CEILING TILE COMPOSITION Composition of the various acoustical tile types used in commercial construction include mineral fiber base and glass fiber base. A jute fiber substrate that is completely recyclable is also available in antimicrobial, nonsagging, 2 by 2 ft (610 by 610 mm) and 2 by 4 ft (610 by 1,219 mm) lay-in panels. Cellulose base tiles are used primarily in residential construction and are not as durable as commercial-grade panel construction. Construction of mineral fiber base acoustical panels is cast, wet-felted, and nodular, and is available in a number of textures and acoustical properties. Source: Armstrong Ceiling Systems. LIGHT POCKET WITH DRYWALL CEILING 7.452 ACOUSTICAL TILE TEXTURES 7.454 Source: Armstrong Ceiling Systems. Contributors: Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. Doug Sturz and Carl Rosenberg, Acentech, Inc., Cambridge, Massachusetts. Mark A. Rogers, PE, Sparling, Seattle, Washington. Jim Johnson, Wrightson, Johnson, Haddon & Williams, Inc., Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 217 INTERIOR F INISHES SQUARE-EDGED KERFED TILE FOR CONCEALED SUSPENSION SYSTEMS 7.455 incidence. NRC is important in any closed space where reverberation time and noise levels are an issue. Such spaces are open-plan offices, conference rooms, lobbies, open work areas, classrooms, gymnasiums, cafeterias, reception areas, healthcare exam rooms, doctor’s offices, and retail spaces. The higher the NRC number, the greater is the capability of the ceiling tile to absorb sound. Articulation class is a measure of the reflected speech noise that passes over the top of partitions, either wall or furniture, into adjoining workstations. AC is important between adjacent workstation cubicles in open office spaces. A ceiling system with AC less than 150 is low performance, whereas one with AC greater than 180 is high performance. BEVELED-EDGED KERFED TILE FOR CONCEALED SUSPENSION SYSTEM 7.456 FIRE RESISTANCE OR FIRE RATING Fire-resistant ceiling panels and suspension systems are tested along with the roof or floor construction type by Underwriters Laboratories (UL) to create UL fire-resistant ceiling assemblies that form a layer to contain a fire within a space. These assemblies are assigned fire ratings of one, two, three, or four hours. After establishing the hourly rating needed to meet the code requirements, the existing or designed roof or floor structural elements are then determined. Fire-resistance ratings of ceiling assemblies are tested by ASTM International (ASTM) using three tests: TEXTURES AND COLORS Acoustical tiles are finished with varying textures, ranging from fine to coarse. The typical color of acoustical tile is white, although some manufacturers offer additional colors. Colors may affect the light reflectance of the ceiling. EDGE PROFILES Common edge profiles are square or beveled with kerfed (grooved or notched edge, which accepts and conceals the suspension system) or tongue-and-groove edges. Square-edged acoustical tiles appear more monolithic when installed; however, the joints are sometimes very obvious if the light striking the ceiling is at a low angle of incidence. Acoustical tiles are also subject to edge damage when the tiles are removed and reinstalled when access is needed to the plenum, thus requiring their replacement with new acoustical ceiling tiles. Beveled-edged tiles provide an eased edge, which creates a slight shadow line between tiles. When moving the tiles after installation, the use of beveled edges can minimize damage. SOUND ABSORPTION AND SOUND ISOLATION In open office areas, the insulation of an acoustical tile ceiling will improve the amount of acoustic privacy between partial-height partitioned workstations. Within closed offices or rooms, an acoustical tile ceiling can improve the transmission of noise from one room to another, if used with appropriate partition types. Manufacturers of acoustical tile ceilings categorize the acoustical features of their products according to industry standard designations for the range of sound absorption. Ceiling attenuation class (CAC), noise reduction coefficient (NRC), and articulation class (AC) are the three acoustical categories that are used to compare sound absorption between acoustical ceiling tiles. Ceiling attenuation class is a measure that rates the performance of a ceiling system as a barrier to airborne sound transmission through a common plenum between adjacent closed spaces, such as offices. CAC is important between closed spaces and closed rooms to adjacent spaces such as corridors, offices, conference rooms, classrooms, learning areas, healthcare exam rooms, and doctor’s offices. A ceiling system with a CAC greater than 25 is considered low performance, while one with a CAC of 38 or higher is high performance. Noise reduction coefficient is a measure that rates the overall sound absorption of a material when used in an enclosed architectural space such as an office, where sound is reflected at angles of Contributors: Keith McCormack, CCS, CSI, RTKL Associates, Baltimore, Maryland. Setter, Leach & Lindstrom, Inc., Minneapolis, Minnesota. Blythe + Nazdin Architects, Ltd., Bethesda, Maryland. • ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and Materials, measures in hours the degree to which an entire assembly, not individual components, withstands fire and high temperatures. Specifically, it measures an assembly’s ability to prevent the spread of fire between spaces while retaining its structural integrity. • ASTM E 84, Standard Test Method for Surface Burning Characteristics of Building Materials, measures the surface flame spread and smoke development of a ceiling material. This test establishes the relative rate at which a flame will spread over the surface of the material. The rate is compared against a rating of 0 for inorganic reinforced cement board and a rating of 100 for red oak. • Building codes generally require that acoustical ceiling tiles typically must have a minimum Class A fire rating. Class A ceilings have a flame spread rating of 25 or less and a smoke spread of 450 or less. Fire-resistant ceilings are specially formulated to provide enhanced resistance against structural failure. Fire-resistant suspension systems have patented expansion reliefs, to help maintain the structural integrity of the ceiling. INTE R I O R CO N ST RU CT I O N 217 Light reflectance values are generally lower for those acoustical tiles with textured and embossed patterns. Integrally colored tiles may affect the LR value. Unless the ceiling surface is to be used as a distributor of illumination, lower LR values may not be of concern. SUSPENDED ACOUSTICAL PANEL CEILINGS Acoustical panel ceilings are composed of prefabricated ceiling units, installed in a metal suspension system. They are used where sound attenuation and accessibility to the ceiling interstitial or plenum space above are desired. Acoustical ceilings are large visual elements within a space, and are design elements as well as acoustical features. Partitions, light fixtures, ceiling diffusers, sprinklers, and other devices are attached to or installed within these ceilings, so coordination with the ceiling layout is critical. Acoustical panels are installed on an exposed metal grid system suspended from the underside of the structure above. Common acoustical panel sizes are available in square and rectangular shapes ranging from 24 by 24 in. (610 by 610 mm) to 24 by 48 in. (610 by 1,220 mm), up to 60 by 60 in. (1,524 by 1,524 mm). Thicknesses include 5⁄8 in. (16 mm), 3⁄4 in. (19 mm), and 1 in. (25 mm), with other thicknesses available for special applications. Acoustical considerations, light reflectance, sag resistance, antimicrobial properties, VOC emissions, and durability concerns with acoustical ceiling panels are the same as with acoustical tile ceilings. Because the panels are larger, acoustical performance may be improved, but sag resistance should be taken into account when determining panel size. Fire-resistant acoustical ceiling assemblies are available, when used with applicable UL designs. Manufacturers also address seismic concerns. CEILING PANEL COMPOSITION Several of the same types of materials used for acoustical tiles are employed as acoustical panels: water felted, cast or molded, and nodular. Special acoustical panels composed of a ceramic and mineral fiber composite are used where increased durability, cleanliness, and resistance to humidity and fumes are required. Mylarfaced acoustical panels are used in cleanroom areas, food service, and other applications where ability to be cleaned is important. The materials for fiberglass panels are processed from a molten state into fibrous glass strands, and then formed into sheet and board stock. A separate dimensionally stable facing material is laminated to the fiberglass core to provide texture and pattern. Backings are available to improve acoustical qualities of the fiberglass panels. The quantity of light reflected by a surface is known as light reflectance, defined in ASTM E 1477, Standard Test Method for Luminous Reflectance Factor of Acoustical Materials by Use of Integrating-Sphere Reflectometers. Recycled content is increasing within acoustical panel manufacturers’ product lines, depending on the product selected. Many manufacturers are addressing the issue of sustainability within the manufacturing process, and recycling of old ceiling panels is becoming widespread. Illuminance (the quantity of light striking a surface) is measured in footcandles, or lux (metric measure). One footcandle is approximately 10 lux. A footcandle is the average illumination resulting when 1 lumen of light falls on 1 sq ft (0.09 sq m) of surface. The total number of lumens on a surface divided by the area of the surface equals footcandles. Perforated metal ceiling panels offer durability, humidity resistance, and low maintenance, along with great aesthetics and acoustics. The standard material is electrogalvanized steel. Aluminum is also available. Panels come in unperforated, microperforated, and extra microperforated styles. Factory-applied powder-coated finishes add extra durability, as well as scrubbable and washable surfaces. Acoustical tiles with a high light reflectance (LR) provide greater levels of reflected light from the ceiling plane. LR is measured in values from 0.00 to 1.00. High-LR ceiling tiles are particularly effective in open office areas with indirect light sources, where glare is reduced at the work plane and where spaces incorporate daylight as a light source. Usable light is increased and is more evenly distributed. Acoustical ceilings that have a light reflectance above 0.83 are considered to be high-LR ceilings, but some products are available that exceed this number and reflect more light. The maximum light reflectance of acoustical ceilings is 0.89 or 0.90. After review of the planned illumination levels, high LR ceilings may make it possible to reduce the number of light fixtures within a space, thereby reducing initial installation costs and long-term energy costs. Wood ceiling panels can add warmth and character to a space. Wood panels are available in a wide range of sizes and finishes; they are available perforated or unperforated, formaldehyde-free, with a Class A fire rating, and made from FSC-certified woods. LIGHT REFLECTANCE TEXTURES AND COLORS Like most acoustical tiles, acoustical panels are finished with varying textures, ranging from fine to coarse. The typical color of acoustical panels is white, although some manufacturers offer additional colors. Colors may affect the light reflectance of the ceiling. EDGE DETAILS Common edge details are square or tegular (reveal) shapes. Acoustical panels with these edge details are easily dropped in place within the suspension system and are pushed up to access the ceiling plenum. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 218 I N T E R IO R CO NST RU CTION Square-edged acoustical panels are economical and are installed on the exposed ceiling suspension grid flanges. Square-edged panels do not conceal the suspension grid. Page 218 INTERIOR F INISHES ACOUSTICAL PANEL CEILING ASSEMBLY 7.459 Tegular-edged acoustical panels have a reveal edge, which allows the panels to extend below the suspension system, partially concealing the metal grid. Tegular edges can be square, angled, beveled, stepped, or other special shapes, and are generally selected for their appearance. Beveled edges, often found on tegular-edged units, form an eased edge condition, which softens the line of the perimeter of the panel. When moving panels after the initial installation, beveled edges can minimize edge damage due to accidental bumping of the panel on the grid. Step tegular panels offer designers more shadow lines. Crown, coffer, and convex edges are available to create a coffered ceiling using mineral fiber panels and standard ceiling grid. Some manufacturers offer a downward accessible ceiling edge that partially or completely hides the ceiling grid and creates the look of a concealed spline ceiling. This edge is available on mineral fiber, fiberglass, wood, and metal ceiling panels. ACOUSTICAL CEILING TILE SUSPENSION SYSTEMS 7.460 COFFERED EDGE 7.457 Source: Armstrong Ceiling Systems. DOWNWARD ACCESS EDGE 7.458 Source: Armstrong Ceiling Systems. EXPOSED SUSPENSION SYSTEMS CONCEALED SUSPENSION SYSTEMS Exposed acoustical ceiling panel suspension systems are composed of main and cross-tee components, installed at the desired height by hanger wires. The suspension system is typically fabricated from factory-coated steel. Additional types include galvanized steel systems for improved resistance to moisture, and aluminum and stainless steel for other special installation requirements. Fire-rated suspension systems are available with prenotched expansion relief segments to resist suspension system failure resulting from heat expansion of the grid. Concealed acoustical panel ceiling suspension systems are installed at the desired height by hanger wires, which support the metal T- or Z-shaped grid components. The suspension system is typically fabricated from factory-coated steel, with galvanized steel systems available for improved resistance to moisture. COMPONENTS The visible components of an exposed ceiling suspension system include interlocking main beams and cross tees, installed in a prescribed grid to accept the acoustical panels. Main beams are typically installed on hanger wires spaced at 4 ft (1,219 mm) on center along the beam. Angle or channel-shaped moldings are used for perimeter acoustical panel support. Hanger wires support the main and cross tees from the structure above and are spaced according to the manufacturer’s recommendations and as project conditions require. Many manufacturers are producing suspension systems with high recycled content (HRC). They are manufactured from hot-dipped, galvanized steel made from recycled steel produced in the United States. The recycled content is between 57 and 66%. LEED credits that apply to this are waste management, recycled content, and local materials. Contributors: Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. Keith McCormack, CCS, CSI, RTKL Associates, Baltimore, Maryland. Setter, Leach & Lindstrom, Inc., Minneapolis, Minnesota. Blythe + Nazdin Architects, Ltd., Bethesda, Maryland. Concealed suspension systems for acoustical tiles integrate above-ceiling access areas into the system. Access is upward or downward, depending on the system. Care should be taken to prevent damage to the ceiling tile during installation and maintenance of the system and above-ceiling elements. COMPONENTS The concealed suspension system is composed of interlocking 15/16 in. (24 mm) wide double-web main beams and cross tees. Main beams are typically installed on hanger wires spaced at 4 ft (1.2 m) on center along the beam. Angle or channel-shaped moldings are used for perimeter acoustical tile support. Hanger wires support the main and cross tees from the structure above and are spaced according to the manufacturer’s recommendations and as project conditions require. STRUCTURAL PERFORMANCE Ceiling suspension systems for acoustical panels are designated as light, intermediate, or heavy duty. Prior to specifying a suspension system, the anticipated loads on the ceiling should be reviewed to determine the most suitable type. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 219 INTERIOR F INISHES FIRE-RESISTANCE-RATED SUSPENSION SYSTEMS Fire-resistance-rated suspension systems conform to the UL design for fire-rated performance. Expansion points are provided at specific intervals to alleviate stresses on the grid in case of fire. Cross-tee end clips and other devices must be used as required by UL and local codes. The acoustical panels installed within the fireresistant suspension system must also be of a fire-resistive nature. SHADOW MOLD WITH TEGULAR-EDGED ACOUSTICAL PANEL 3/8 IN. (10 MM) 7.463 INTE R I O R CO N ST RU CT I O N 219 CROWN COFFER AND 9/16 IN. (14 MM) EXPOSED TEE SYSTEM 7.466 SEISMIC DESIGN For the installation of an acoustical panel ceiling in locations with seismic design requirements, review suspension systems. ACOUSTICAL CEILING PANEL INSTALLATION Source: Armstrong Ceiling Systems. There are many details for installation of suspended ceiling panel systems in ceilings of other materials, and for ceiling and wall intersections. In addition, various types of panel edges have their own suspension grid details. Coffered ceilings require specific edge designs. In addition, perimeter air returns necessitate details that integrate suspended ceilings with ceiling and wall construction. FLUSH ACOUSTICAL CEILING PANEL AT GYPSUM BOARD CEILING 7.461 PERIMETER SLOT AIR RETURN 7.467 SQUARE LAY-IN AND ALUMINUM CLEANROOM PANEL 7.464 Source: Armstrong Ceiling Systems. BEVELED TEGULAR DOUBLE REVEAL 7.465 L-MOLD WITH SQUARE-EDGED ACOUSTICAL PANEL 7.462 INTEGRATED ACOUSTICAL PANEL CEILING SYSTEM An integrated acoustical panel ceiling system consisting of a proprietary concealed extruded aluminum grid and panels that is 100% accessible is available. A unique torsion spring and butterfly plate permits individual panels to be hinged down or completely removed for access to mechanical and electrical services in the plenum space. The grid is suspended using hanger wires, rods, and similar suspension components. PANELS AND FINISHES All panels are fabricated in a variety of types, sizes, geometric shapes, vaults, thicknesses, and finishes. Panels can be covered with fabric or vinyl, an acoustically transparent finish that looks like gypsum board, or a unique metallic finish. Panels can also be perforated wood or wood plank sections. Source: Armstrong Ceiling Systems. Fabric panels have an aluminum concealed square edge, with 1/8 in. (3 mm) defined joint. The panel core has a density of 6 to 7 lb/cu ft (96 to 112 kg/cu m). Panel thickness is 1 in. (25 mm) or 1-1/2 in. (38 mm), with an NRC of 0.90 or 0.95, respectively. Panel sizes can be up to 120 by 60 in. (3,050 by 1,525 mm). Vinyl panels are framed like fabric panels. Vinyl corners are heat sealed, and a 1 mil clear vapor retarder is adhered to the back panel. Panel thickness is 2 in. (50 mm), with an NRC of 1.05. Panel sizes can be up to 120 by 48 in. (3,050 by 1,220 mm). Acoustically transparent panels are similar to fabric and vinyl panels with a 1/16 in. (1.5 mm) thick, 16 to 20 lb/cu ft (256 to 320 kg/cu m) high-density integral facer designed to receive a nonbridging acoustically transparent coating. A 1 mil clear vapor Contributors: Keith McCormack, CCS, CSI, RTKL Associates, Baltimore, Maryland. Setter, Leach & Lindstrom, Inc., Minneapolis, Minnesota. Blythe + Nazdin Architects, Ltd., Bethesda, Maryland. Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. Richard Riveire, AIA, DMJM/Rottet, Los Angeles, California. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 220 I N T E R IO R CO NST RU CTION retarder is adhered to the back panel. Panel thickness is 1-1/16 in. (27 mm), with an NRC of 0.90. Panel sizes can be up to 72 by 48 in. (1,830 by 1,220 mm). Wood finished panels are available in two types: • Natural wood veneer finish: Acoustical absorption is achieved by a patented perforation technology in combination with high-performance acoustical cores. • Wood edge panels consist of a density mat faced core, 6 to 7 lb/cu ft (96 to 112 kg/ cu m), laminated between a layer of 1/4 in. (6 mm) thick face and a 1/8 in. (3 mm) high-density fiberboard (HDF) perforated backing board, with internal fire-treated particleboard framing as required for edge conditions. MOUNTING SYSTEMS Page 220 INTERIOR F INISHES CEILING MATERIALS Translucent and perforated PVC membranes are available. Translucent PVC material can be backlit, creating a luminous appearance. Care should be taken to ensure that the frame profile is not projected onto the backlit surface, creating a shadow. Photographic-quality artwork can be printed on PVC membranes. PVC systems are available in more than 100 colors. Custom colors are also available, but typically only with a large order. Matte, satin, suede, metallic, and reflective finishes are available. The PVC fabric is virtually impermeable to air and moisture (waterstaining problems are eliminated), and can easily be cleaned with a soft cloth and liquid cleaner. However, PVC is a petrochemical and has problems with toxicity throughout its life cycle. In the panel system with all panels fully accessible, concealed extruded aluminum grids are suspended using hanger wires, rods, and similar suspension components. The panels are held apart from each other by the extruded aluminum grid by a ±1/8 in. (3 mm) defined joint. Using a special tool in that joint allows the panels to be pulled downward to gain access to the plenum space above the ceiling system. A minimum of 5 in. (127 mm) is required behind the panel for torsion spring clearances. Polyester stretched ceiling systems can resemble plaster or gypsum board ceilings. Textile ceiling finishes must have a Class A flame spread index and be protected by sprinklers. Directly suspended acoustical ceiling panels are installed to a concealed metal suspension system. This system allows for every other ceiling panel to be accessible. Stretched ceiling systems offer a quick, dust-free installation without odors or fumes. These systems are installed relatively quickly; however, experienced installers are required. All forms of penetrations and recessed or surface-mounted fixtures, including lighting, alarms, sprinklers, and ventilation equipment, can be accommodated. Penetrations are all cut in the field to ensure a proper fit. These systems can be installed over existing ceilings, commonly gypsum board or acoustical tile suspension systems, either with or without acoustical tile installed, depending on the acoustical characteristics required. For curved installations, wood or metal frames can be used at the perimeter. Panels can also be mounted using a mechanical Z-clip slide-andengage method of fastening directly to a firm substrate such as gypsum board, concrete, steel deck, or wood. CANOPIES AND CLOUDS Canopies and clouds appear to float above the space. They can be flat circles, ovals, rounded squares, and squares, or take on more vertical movement with serpentine forms, wave shapes, vaults, or domes. Clouds and canopies create acoustical absorbency or accent options in a system that is easy to specify and install. They create an ideal solution for acoustically challenging or open plenum space. They reduce acoustical reverberation time in the space, reduce noise levels, and increase speech intelligibility. Some manufacturers are producing these clouds in kits, with all panels, grid, and trim cut to length in the factory, so the contractor is only responsible for installing the cloud. Clouds and canopies can be many different colors, materials, and perforated or unperforated. DRYWALL CEILING WITH DRYWALL CLOUD— SECTION 7.469 Antimicrobial and antifungal treatments can be integrated into the ceiling material for applications such as hospital operating rooms, cleanrooms, laboratories, and food preparation spaces. Source: Armstrong Ceiling Systems. INSTALLATION ACOUSTICAL CEILING WITH ACOUSTICAL CLOUD FIXTURE—SECTION 7.470 Access to mechanical space behind the ceiling is achieved by temporarily removing the flexible material. Lights, sprinklers, and HVAC registers and grilles can be incorporated in the ceiling; penetrations are field cut. PENETRATION AT LIGHT FIXTURE 7.468 Source: Armstrong Ceiling Systems. METAL PANEL CEILINGS Metal ceiling panels are available in a variety of sizes, including 24 by 24 in. (610 by 610 mm), 48 by 24 in. (1,219 by 610 mm), and 72 by 16 in. (1,829 by 406 mm). Edge styles include beveled concealed, flush and square tegular, hook-on, nail-up, and lay-in. The panels are available in a wide variety of face patterns, including 3, 4, and 6 in. (76, 102, and 152 mm) square cells, diamonds, and many others. STRETCHED CEILING SYSTEMS Stretched ceiling systems utilize lightweight, long-span, continuous sheets of prefinished material to create a large, smooth ceiling plane or a warped, curved ceiling. The maximum span of a stretched ceiling system is dictated by the material. Spans of up to 16 by 40 ft (5 by 12 m) are typical. METAL PANEL WITH GYPSUM BOARD SPLINE 7.471 Stretched ceiling systems consist of three basic components: a flexible ceiling material, a perimeter rail, and a fitting that attaches the material to the rail. The material is either a polyvinyl chloride (PVC) membrane or a woven fabric, typically made of fireresistant polyester. The rail is mounted around the perimeter of the space in either straight or curved configurations. Intermediate supports are not commonly required because of the long spans that are possible with stretched ceiling systems. Rails can be either visible or fully concealed. Source: Armstrong Ceiling Systems. Contributor: Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 221 INTERIOR F INISHES ACOUSTICAL METAL PAN CEILINGS Acoustical metal pan ceilings are used where aesthetics, durability, and ease of maintenance are desired. Metal pan ceilings are available in many finishes and colors, providing a number of design options and aesthetics. Acoustical metal pan ceiling units enclose sound attenuation pads, which provide varying qualities of acoustical control at the ceiling plane. rying channels hung from the structure above. Both types are suspended from hanger wires, with the main tees usually located at 48 in. (1,219 mm) on center, maximum. Cross-connector clamps are installed at grid intersections of the main and cross tees to provide added strength. METAL PAN FEATURES 7.473 Metal pan ceilings are typically snapped or hooked in place on a concealed suspension system or are installed as lay-in units on traditional exposed ceiling suspension systems. Products are available that incorporate an exposed suspension system and metal pans with special edge details, providing a semiexposed, narrow reveal installation. Metal pan ceilings can be integrated with air diffusers and light fixtures, depending on the manufacturer’s product offerings. SIZES Linear metal panel dimensions vary by manufacturer, but a common module width range is from 2 to 8 in. (51 to 203 mm). Standard lengths are commonly 12 and 16 ft (3.6 and 4.8 m), but can be tailored to a particular installation with custom lengths. Depths of panels vary, with deeper panels providing a stronger linear effect to the ceiling. SIZES Sizes of metal pans range from 12 by 12 in. (305 by 305 mm) to 24 by 24 in. (610 by 610 mm). Large units are available from some manufacturers in square and plank-type pans. Standard metal pan size offerings vary by manufacturer. Custom sizes are available. MATERIALS The most common material for linear metal ceilings is roll-formed aluminum, with typical thicknesses of 0.020, 0.025, and 0.032 in. (0.5, 0.6, and 0.8 mm). Aluminum linear panels are preferred for high-humidity areas and in spaces where the environment fluctuates, as well as for exterior applications. Stainless steel performs well, but is typically more costly than aluminum or steel panels. THICKNESSES Metal pans are commonly offered in 20 and 24 gauge for steel pans, and 0.032 and 0.040 in. (0.8 and 1 mm) for aluminum. The numerous metal finishes available provide various aesthetic and design options. Steel pans can be galvanized, baked enamel, powder-coated, or electroplated. Aluminum pans can be mill finished, anodized, or painted. FINISHES There are numerous metal finishes available for linear metal ceilings. Aluminum panels are available mill finished, anodized, or colored with a baked-enamel finish. Steel panels are available with baked enamel, powder-coated, or electroplated finishes. Stainless steel panels are available with brushed or mirror finishes. Metal pans are available in standard flat panels, as well as in curved and corrugated units. INSTALLATION TYPES Suspension systems for metal pan ceilings are similar to those used for acoustical panel and tile installations. Classifications of the suspension systems are typically intermediate and heavy duty, depending on the type and weight of the metal pans. Direct-hung suspension systems are hung from the structure above. In indirect-hung systems, the main tees are attached to carMETAL PAN CEILING 7.472 Linear metal panels are available in smooth, perforated, or textured surfaces. ACOUSTICAL PROPERTIES The acoustical qualities of metal pan ceilings vary depending on the type of metal pan used, the perforation quantity and type, and the project conditions. Sound waves are transmitted through the perforations in the metal pan, so the use of sound attenuation pads reduces the sound transmitted. Sound is transmitted through the ceiling plenum if ceiling-height partitions are installed; therefore, sound attenuation panels will improve acoustics. Fiberglass is the most common material for sound attenuation pads. These pads are typically encapsulated so that no loose fiber can become airborne, thus compromising the indoor air quality. When perforated metal pans are installed without sound attenuation pads, a black backing scrim is installed inside the panel to eliminate any visible elements above the ceiling. Some manufacturers provide mineral fiber inserts in the metal pans to improve the ceiling attenuation class (CAC), which rates the ceiling’s capability as a barrier to sound transmission between spaces. The noise reduction coefficient (NRC), a measurement of the capability of an acoustical unit to absorb sound, is greater with fiberglass inserts in the metal panels, but the CAC is lower. Nonperforated metal panels are generally rated with a low NRC range of 0.00 to 0.10. NRCs for perforated metal panels range from 0.65 to 0.90. RECYCLED CONTENT Many manufacturers have integrated recycled materials into their metal pan ceiling fabrication, although the percentage of recycled content varies among manufacturers and products. Contributors: Keith McCormack, CCS, CSI, RTKL Associates, Baltimore, Maryland. Setter, Leach & Lindstrom, Inc., Minneapolis, Minnesota. Blythe + Nazdin Architects, Ltd., Bethesda, Maryland. Scott A. McAllister, AIA, LEED AP, Gensler, Dallas, Texas. Linear metal ceilings are distinctive in appearance and are used where strong linear aesthetics, durability, and ease of maintenance are desired. Metal surfaces are available with many finishes and colors, allowing for a number of design options for the metal ceiling. Special suspension systems allow installation of custom radius configurations, as well as flat horizontal ceilings. Linear metal ceilings are typically installed as snap-in units on a concealed suspension system, and some can accept companion integrated light fixtures. Linear metal ceilings are fabricated from aluminum, steel, or stainless steel. Options include metal panel (slat) sizes, metal coating types, colors, textures, and acoustical insulation. Linear baffle ceilings are also available, but typically are not installed with acoustical insulation. Acoustical metal pan ceilings are typically fabricated from steel or aluminum. Options include metal pan sizes, metal coating types, colors, textures, perforation patterns, and acoustical insulation pads. SUSPENSION SYSTEMS LINEAR METAL CEILINGS TYPES TYPES Three common installation types are snap-in, hook-on, and lay-in. Edge details are square, beveled, and reveal, and are shaped to ensure proper engagement and alignment within the suspension system. Perimeter tiles may be cut in the field, unless not recommended by the manufacturer. For integration of ceiling fixtures and devices, factory-provided cutouts can be located in metal pans. This requires the coordination of the entire reflected ceiling plan for areas with metal pan ceilings. INTE R I O R CO N ST RU CT I O N 221 Profiles of linear metal ceilings include flat pans and planks, tubular, blade, and baffle shapes. Edge details are formed to ensure proper engagement and alignment within the suspension system. Metal panels intended for interior applications have a roll-finished edge for added strength. LINEAR METAL CEILING WITH SOUND INSULATION 7.474 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 222 I N T E R IO R CO NST RU CTION LINEAR METAL CEILING—HEIGHT CHANGE 7.475 Page 222 INTERIOR F INISHES GRID TYPES Suspended decorative grids are composed of U-shaped blades rollformed from sheet metal, formed into modular grid units, and suspended by a ceiling suspension system similar to those used on typical acoustical ceiling installations. Some suspended grid products can support light fixtures, signage, speakers, and other devices typically installed at the ceiling plane. SHEET METAL AND STAMPED METAL CEILINGS Stamped metal ceilings are sometimes found in older buildings, where they may be hidden under a newer suspended ceiling. Older stamped metal ceilings can be rescued by carefully patching them with pieces of matching material retrieved from places that will not be seen in the new design. New stamped metal can be purchased in sheet or modular tile forms. Stamped metal ceilings can be painted; most are bordered by matching coves at the wall joints. ACOUSTICAL PROPERTIES Acoustical properties of linear metal ceilings vary depending on the type of metal pan used, type of sound attenuation used, and project conditions. Sound waves pass through the reveals between the panels, so the use of sound attenuation above these gaps will reduce the sound transmitted. Sound passes through the ceiling plenum if ceiling-height partitions are installed in areas with linear metal ceilings; therefore, sound attenuation batting above the ceiling will improve acoustics slightly. Microperforations are available on some metal panel products, which improve the acoustical qualities of the system, especially if used in conjunction with sound attenuation batting. NRC ratings average around 0.70 to 0.90, depending on installation conditions. Ceiling panels with wood veneer finishes are also available. Perforated wood-finished panels can have acoustically absorbent material inside. The panels are edge banded and some open downward for ease of access. Manufacturers of ceiling panels provide wood and faux wood options. Standard 2 by 2 ft (610 by 610 mm) metal ceiling panels can be inexpensively powder coated with realistic printed images of wood. Suspended wood linear ceilings are attached with clips to a rail. They are available in a variety of wood species, including oak, ash, maple, poplar, and red cedar, with factory-applied finishes. BEADBOARD PLANKS 7.478 Stamped metal ceiling products are highly sound reflective. They are available perforated for better sound absorption. Stamped metal ceiling tiles can be inserted into standard 24 in. (610 mm) square ceiling suspension systems. These tiles simplify installation and access for equipment. If the ceiling is to be painted, any grilles mounted in the grid can be painted to match. STAMPED METAL CROWN MOLDING 7.477 SUSPENSION SYSTEMS Concealed suspension systems for linear metal ceilings are similar to those used for acoustical tile installations. Classifications of the suspension systems are typically intermediate and heavy duty, depending on the type and weight of the linear metal panels. Carrier suspension systems are hung from the structure above by hanger wires, with main tees usually located at 48 in. (1,219 mm) on center, maximum. GLASS FIBER REINFORCED GYPSUM CEILING COMPONENTS SUSPENDED DECORATIVE GRIDS Suspended decorative grids are open-framework grids, used to provide definition to the ceiling plane and to screen above-ceiling elements. Grids do not enclose the ceiling plenum and are suspended from the structure above. Decorative grids allow for easy access to lighting, HVAC, and sprinkler systems installed above the ceiling plane. CELL PANELS 7.476 WOOD AND WOOD PRODUCT CEILINGS There are a variety of wood products used for ceilings, including beadboard, wood decking or planks, and wood-finished ceiling panels. Beadboard, 5/16 in. (8 mm) thick and around 3-1/2 in. (89 mm) wide, can be used for ceilings. A routed groove down the center of each plank creates the illusion of two narrow planks when installed. Beadboard is installed at right angles to the ceiling joists. Edges at walls are easily trimmed with molding. Due to its light weight, glass fiber reinforced gypsum (GFRG) is popular for use in the fabrication of domed, coffered, and vaulted ceilings. GFRG ceilings are suspended from integral fastening points inserted during the casting process. Larger ceiling areas may exploit the casting process by utilizing repeated forms from a limited number of molds. DOMED CEILING INSTALLATION 7.479 Wood decking or planks span beams to form the structural platform of a floor or roof. The underside of the planks may be left exposed as the finished ceiling. Wood planks are typically 5-1/4 in. (133 mm) wide and have V-shaped tongue-and-groove joints. Channel groove, striated, and other machined patterns are available. There is no concealed ceiling space with such a system. Wood ceilings are often finished with stains and varnishes. A dark ceiling finish, especially a shiny one, may appear lower than it actually is. Combined with a dark-colored floor, it can create the illusion of a flat, horizontal space. Wood ceilings made from light-colored or highly patterned woods, like knotty pine, can add warmth and character to a space. In some cases, wood ceilings are painted, either to reflect more light or to obscure unattractive wood. Wood ceilings are usually highly sound reflective. Sometimes designers use lattices or baffles of wood in an attempt to improve sound absorption. Such efforts may improve sound diffusion but must be topped with acoustically absorbent materials in order to significantly increase sound absorption. Contributors: Keith McCormack, CCS, CSI, RTKL Associates, Baltimore, Maryland. Setter, Leach & Lindstrom, Inc., Minneapolis, Minnesota. Blythe + Nazdin Architects, Ltd., Bethesda, Maryland. Corky Binggeli, ASID, Materials for Interior Environments, John Wiley & Sons, Hoboken, NJ, 2008. Source: Casting Designs, Inc., Fort Worth, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 223 BUILDING SERVICES COFFERED REFLECTED CEILING PLAN 7.480 INTE R I O R CO N ST RU CT I O N 223 CERAMIC TILE CEILINGS 7.481 COFFERED CEILING SECTION AT LIGHT COVE 7.482 Source: Casting Designs, Inc., Fort Worth, Texas. CERAMIC TILE CEILINGS Ceramic tile may be used for ceilings in showers and other small spaces where water is present. Ceramic tile installations on cementitious backer board can be heavy and cumbersome to install overhead. Source: Casting Designs, Inc., Fort Worth, Texas. BUILD ING SE RVICE S CONVEYING SYSTEMS tem are supported by the hoist machine. The elevator and its counterweight are connected with steel ropes. ELEVATORS Hydraulic elevators use an oil hydraulic driving machine to raise and lower the elevator car and its load. Lower speeds and the piston length restrict the use of this system to heights of approximately 55 ft (16 m). Although it generally requires the least initial installation expense, this elevator type requires more power to operate. Hoistway: This is a vertical shaft for the travel of one or more elevators. It includes a pit and usually terminates at the underside of the machine room in a traction system, and at the underside of the roof over the hoistway in a hydraulic system. SELECTION CRITERIA SYSTEMS An elevator system includes a hoistway, machine room, elevator car, and waiting lobbies. An elevator system is a major building component, and, as such, must be carefully considered throughout the design process. Decisions about the number, size, speed, and type of elevators for an installation are based on a variety of factors, including the handling capacity and quality of service desired. Proper selection also depends on the type of tenancy, number of occupants, and building design (number of floors, floor heights, building circulation, and other factors). In addition, passenger elevators on accessible routes should comply with the requirements of the 2010 ADA Standards for Accessible Design. Traction elevators are power elevators in which the energy is applied by means of an electric driving machine. Medium to high speeds and virtually limitless rise allow this elevator type to serve high-rise, medium-rise, and low-rise buildings. Machine room: For a traction elevator, this is usually located directly above the hoistway, but may also be situated below, to the side, or to the rear of it. The machine room contains elevator hoisting machinery and electronic control equipment. Service elevators in industrial, residential, and commercial buildings are often standard passenger elevator packages modified for service use. Elevators should be located where they can provide efficient and accessible service. The operational systems (hoistway pit and machine room) and passenger spaces (lobby and elevator car) must be accommodated as well. Freight elevators are usually classed as general freight loading, motor vehicle loading, industrial truck, or concentrated loading elevators. General freight loading elevators may be electric drum-type or traction or hydraulic elevators. Elevator car : Guided by vertical rails on each side, the car (also called a cab) conveys passengers or freight between floors. It is constructed within a supporting platform and frame. Design of the car focuses on ceiling, wall, floor, and door finishes, and the accompanying lighting, ventilation, and elevator signal equipment. TYPES Private residential elevators may be installed only in a private residence or to serve a single unit in a building with multiple dwelling units. By code, elevators in private residences are limited in size, capacity, rise, and speed. The car and frame of a hydraulic elevator system are supported by a piston or cylinder. The car and frame of a traction elevator sysContributors: Tile Council of America, Inc., Anderson, South Carolina. Jess McIlvain, AIA, CCS, CSI, Jess McIlvain and Associates, Bethesda, Maryland. Mark Forma, Leo Daly Company, Washington, DC. George M. Whiteside III, AIA, and James D. Lloyd, Kennett Square, Pennsylvania. Elevator waiting lobbies : These are designed to allow free circulation of passengers, rapid access to elevator cars, and clear visibility of elevator signals. All elevator lobbies must be enclosed, with the exception of those at the entry level of main buildings. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 224 I N T E R IO R CO NST RU CTION Page 224 BUILDING SERVICES GEARED TRACTION ELEVATOR 7.486 ELEVATOR TYPES 7.483 TRACTION ELEVATOR HOISTWAY TYPES 7.487 ELEVATOR TYPES BY USE 7.484 NEED/USE PRIVATE GEARED GEARLESS RESIDENTIAL HYDRAULIC TRACTION TRACTION Private residence, very low rise, low speed X — — — Low rise, low speed — X — — Medium rise, moderate speed — — X — High rise, high speed — — — X Low initial cost — X — — No penthouse, lightweight construction X X — — Freight, low rise — X X — Freight, high rise — — X — TRACTION ELEVATOR WITH BASEMENT MACHINE ROOM 7.485 TRACTION ELEVATOR DIMENSIONS RATED LOAD, LB (KG) NOTES 7.485 This is a very specialized application, so consultation with experts is advised. Traction elevators with basement machine rooms are used in new and existing buildings where overhead clearance is limited. 7.487 Side-mounted counterweights allow an optional rear entrance door. A B C D E 2,000 (907) 5-8 4-3 7-4 6-11 3-0 (1,727 mm) (1,295 mm) (2,235 mm) (2,108 mm) (914 mm) 2,500 (1,134) 6-8 4-3 8-4 6-11 3-6 (2,032 mm) (1,295 mm) (2,540 mm) (2,108 mm) (1,067 mm) 3,000 (1,361) 6-8 4-7 8-4 7-5 3-6 (2,032 mm) (1,397 mm) (2,540 mm) (2,261 mm) (1,067 mm) 3,500 (1,588) 6-8 5-3 8-4 8-1 3-6 (2,032 mm) (1,600 mm) (2,540 mm) (2,464 mm) (1,067 mm) 4,500 (2,041) 5-8 7-10 8-4 10-5 4-0 (1,727 mm) (2,388 mm) (2,540 mm) (3,175 mm) (1,219 mm) 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 225 BUILDING SERVICES HYDRAULIC ELEVATOR DIMENSIONS 7.488 ACCESSIBLE EMERGENCY COMMUNICATIONS Elevator cars must provide an emergency two-way communication system between the car and a point outside the hoistway. Controls must be located within accessible reach ranges. When the system includes a handset, the cord must be at least 29 in. (735 mm) long. The system must provide both audible and visible signals; it cannot be limited to voice communication. ACCESSIBLE CAR POSITION INDICATORS Within elevator cars, audible and visible signals are required to identify the location of the car. Visible signals at least 1/2 in. (13 mm) high must be provided for each floor the car serves; these signals must illuminate to indicate the floors at which the car stops or passes. Audible signals for new elevators must be automatic verbal announcements that indicate the floor at each stop. INTE R I O R CO N ST RU CT I O N 225 LIMITED-USE/LIMITED-APPLICATION ELEVATORS Limited-use/limited-application (LULA) elevators must comply with Part XXV of ANSI/ASME A17.1 and are permitted to be used as part of an accessible route in certain conditions. Section 408 of the 2010 ADA Standards for Accessible Design cover technical requirements for LULA elevators. Check applicable accessibility regulations for permitted installations. LULAs move more slowly than other passenger elevators and may not be appropriate when large numbers of people must be served. LULA ELEVATOR—NEW INSTALLATION 7.491 CONTROL PANEL HEIGHT 7.489 HYDRAULIC ELEVATOR DIMENSIONS LEGEND RATED LOAD, LB (KG) A B C D E 2,000 (907) 5-8 4-3 7-4 5-11 3-0 (1,727 mm) (1,295 mm) (2,235 mm) (1,803 mm) (914 mm) 2,500 (1,134) 6-8 4-3 8-4 5-11 3-6 (2,032 mm) (1,295 mm) (2,540 mm) (1,803 mm) (1,067 mm) 3,000 (1,361) 6-8 4-7 8-4 6-3 3-6 (2,032 mm) (1,397 mm) (2,540 mm) (1,905 mm) (1,067 mm) 3,500 (1,588) 6-8 5-3 8-4 6-11 3-6 (2,032 mm) (1,600 mm) (2,540 mm) (2,108 mm) (1,067 mm) 4,500 (2,041) 5-8 7-10 7-5 10-0 4-0 (1,727 mm) (2,388 mm) (2,261 mm) (3,048 mm) (1,219 mm) ACCESSIBILITY Elevators are often used to make buildings accessible to people with limited mobility and to those using wheelchairs. Requirements generally include the following: • Elevator doors must open and close automatically and have a reopening device that will stop and reopen the car and hoistway door if the door is obstructed. • Tactile designations at each jamb of the hoistway doors should be 2 in. (51 mm) high. Include a five-pointed star at the main entry level. • Audible hall signals should sound once for cars traveling in the up direction and twice for cars traveling down. ACCESSIBLE ELEVATOR CARS ANSI/ASME A17.1, Safety Code for Elevators and Escalators, covers general elevator safety and operational requirements. It has been adopted in virtually all jurisdictions. Consult the applicable accessibility regulations for elevator exceptions. Model codes, the Fair Housing Act, and the ADA/ABA Accessibility Guidelines may all have different thresholds for elevator requirements. Inside dimensions of accessible elevator cars must meet the following requirements: • A 5/8-in. (16-mm) tolerance is permitted at 36 in. (915 mm) elevator doors, allowing the use of industry standard 35.4 in. (900 mm) clear-width doors. • Any other car configuration that provides a 36-in. (914-mm) door and either a 60 in. (1,525 mm) diameter or T-shaped wheelchair turning space within the car is permitted. INSIDE DIMENSIONS OF ACCESSIBLE ELEVATOR CARS 7.490 DESTINATION-ORIENTED ELEVATOR SYSTEMS Destination-oriented elevator systems assign passengers to specific cars by requiring them to enter their destination floor at a keypad or by other means, such as use of a coded identification card. Accessibility requirements for destination-oriented elevator systems require both an audible signal/announcement and a visible signal to indicate the car assigned. Therefore, the elevators in the bank must be audibly and visibly differentiated, and the signals or announcements provided at the point of input must be the same as those provided at the car upon arrival. A visible display is required in the car to identify the registered destinations for each trip, and an automatic verbal announcement is required to announce the floor as the car stops. Tactile signs at hoistway jambs are required to identify not only the floor level but also each car. NOTES 7.488 a. A and B are clear inside dimensions. b. Rated speeds are 75 to 200 ft (23 to 61 m) per minute. 7.489 An exception to requirements for control panel height is provided for elevator cars serving 16 or more openings, for which controls as high as 54 in. (1,370 mm) are allowed. Contributors: Rippeteau Architects, PC, Washington, DC. Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, Hyattsville, Maryland. INTERIOR ACCESSIBLE ROUTES AND ELEVATORS Multilevel buildings and facilities require accessible routes between all levels, including mezzanines, unless exempted. Exemptions relating to elevators include: • ADA elevator exception: Buildings with only two floors are exempt from providing an accessible route to the upper or lower level. Buildings with less than 3,000 sq ft (279 sq m) per floor, regardless of height, are exempt from providing an accessible route to upper or lower floor levels. Neither exception applies to shopping centers, offices of professional healthcare providers, public transportation terminals, or state and local government facilities. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 226 I N T E R IO R CO NST RU CTION • Building code elevator exception: Building codes generally exempt a maximum aggregate area of 3,000 sq ft (279 sq m), regardless of the number of levels. Similar to the ADA restrictions, this exception cannot be used in offices of healthcare providers, passenger transportation facilities, or mercantile occupancies with multiple tenants. • Fair Housing Accessibility Guidelines (FHAG) elevator requirements: Accessible routes are required for buildings containing dwelling units, and not public or common-use spaces. FHAG does not require accessible routes to all levels. Instead, the existence or lack of an elevator determines the extent of units covered. When elevators are provided, they generally must serve all floors; an exception is provided for elevators serving only as a means of Page 226 BUILDING SERVICES access from a garage to a single floor. When elevators are not provided, only the ground floor units are subject to the FHAG requirements. In mixed-use construction, an accessible route is required to the first level containing dwelling units, regardless of its location. Consult FHAG for specific requirements. • Levels not containing accessible elements or spaces: For facilities in which only a percentage of the spaces provided are required to be accessible, such as assembly, residential, institutional, and storage facilities, building codes typically do not require an accessible route to serve levels not containing required accessible spaces. Separate requirements for dispersion of accessible elements and spaces may still require multiple accessible levels. Consult the applicable local code. Contributor: Lawrence G. Perry, AIA, Silver Spring, Maryland. An area of rescue assistance is defined in the 2010 ADA Standards or Accessible Design as “an area which has direct access to an exit, where people who are unable to use stairs may remain temporarily in safety to await further instructions or assistance during emergency evacuation.” For use as an area of rescue assistance, the elevator lobby and shaft must be pressurized for smokeproof enclosure, as required by the local building code. The pressurization system must be activated by smoke detectors in locations approved by the local building code. The system’s equipment and ducts must be of two-hour fire-resistant construction. ELEVATOR LOBBY DESIGNED AS AN AREA OF REFUGE 7.495 ELEVATOR LOBBY PLANNING 7.492 ELEVATOR PLANNING DETAILS 7.493 ELEVATOR LOBBY AS AREA OF RESCUE ASSISTANCE ELEVATOR LOBBY 7.494 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 227 BUILDING SERVICES RESIDENTIAL ELEVATORS Guidelines for selecting an elevator for a private residence can be simplified to a few parameters. By code, residential elevators are limited in size, capacity, rise, and speed, and can be installed only in a private residence or in a multiple dwelling as a means of access to a single residence. Pre-engineered systems generally offer only a few options for speed, capacity, aesthetic design, and electronic controls. GLASS-WALLED ELEVATOR CAR 7.497 LOAD CAPACITY The load capacity of drum-type machines is 500 lb (227 kg); the speed is 30 ft (9.1 m) per minute. The load capacity of traction and hydraulic machines is 750 lb (340 kg); the speed is 36 ft (11 m) per minute. PRIVATE RESIDENCE ELEVATOR 7.496 GLASS-WALLED ELEVATOR CARS Observation and glass-back elevators travel outside of a hoistway or in a hoistway open on one side. Machinery is concealed or designed to be inconspicuous. Elevators may be engineered for hydraulic, geared, or gearless use. Cabs can be custom designed with more than 75% of wall area as glass. Only the rear panel is glass in glass-back cabs. Safety barriers must be provided at floor penetrations and the ground floor, completely surrounding that part of the elevator not enclosed by the hoistway. Elevator interiors offer unique and challenging design opportunities for designers. Passenger elevator car proportions are wide and shallow to allow efficient movement into and out of the cab. Changing these proportions can be very expensive. A typical size is 35 sq ft (3.2 sq m), with interior cab measurements of 6 ft 8 in. by 5 ft 4 in. (2,032 by 1,625 mm). Elevator car interiors convey the design concept of the building they serve. An elevator in a corporate business setting will have a very different look from an elevator for a hotel, a hospital, a parking garage, or a high-rise residential building. Each particular car should be viewed in its context and with its unique requirements. Two types of elevator systems are commonly used in private residences: winding-drum machine and hydraulic elevators. Standard residential elevator car size is 36 in. (914 mm) wide, 48 in. (1,219 mm) deep, and 80 in. (2,032 mm) high. Other available car depths are 36 and 60 in. (914 and 1,524 mm). The dimensions given here are appropriate for most applications. Section 409 of the 2010 Standards for Accessible Design permits the use of private residence elevators in multistory dwelling and transient lodging units. CAB SIZE INTENDED USE ELEVATOR SYSTEMS FOR PRIVATE RESIDENTIAL USE • Winding-drum machine traction elevators employ a grooved drum around which the hoisting cable wraps as it operates. This elevator type does not require a counterweight or a machine room above the hoistway, making it more practical for small places than a standard traction system. • Hydraulic elevators in private residences employ either a standard holeless arrangement or a roped hydraulic machine. Both types eliminate major construction and drilling, making the system economical and an excellent selection for retrofit applications. INTE R I O R CO N ST RU CT I O N 227 FINISH SELECTION ELEVATOR CAB INTERIORS Elevators log more passenger miles than any other means of transportation. The design of elevator cab interiors must respond with durability, safety, and practicality. TYPICAL ELEVATOR CAR INTERIOR 7.498 Interior finishes are applied to the inside face of the steel cab walls. Manufacturers’ standard cab finishes are between 3/4 and 1 in. (19 to 25 mm) thick. The resulting inside clear cab dimensions are measured from the inside face of the finished cab walls. These dimensions, shown in the manufacturers’ literature as “cab size,” are the minimum clear dimensions governed by code. If the designer is using custom interior materials in the cab in lieu of the manufacturer’s standard finishes, the applied finishes should not exceed a thickness of 1 in. (25 mm). 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 228 I N T E R IO R CO NST RU CTION Page 228 BUILDING SERVICES TYPICAL ELEVATOR CAR INTERIOR 7.499 CEILINGS AND DOORS Certain steps may be taken at the early stages of a building’s elevator design that add a level of graciousness without adding a lot of cost. Increasing the height of the car interior dramatically improves the feel and is relatively inexpensive. However, increasing the height of the entrances, which are typically 7 or 8 ft (2.1 or 2.4 m), can have significant functional impacts that reduce elevator performance; higher, heavier doors must be propelled more slowly to be safe. The ceilings have to be securely fastened to the car top; they cannot come crashing to the floor during an emergency stop. Top emergency exits are required for use as last-resort removal of trapped passengers. The minimum interior headroom required is 80 in. (2,032 mm), even when movable ceiling panels are used to access the top emergency exit. In buildings where there is no separate freight elevator, passenger cars occasionally serve as the freight elevator. The car should be designed so that the ceiling (which can be much lower than the car top) can be lifted, allowing the transport of much larger materials. Pad pins on the walls allow users to hang protective coverings inside the cab. Providing pad pins is a good practice in all cabs, regardless of whether there is a freight elevator in the building, because when tenants move in, all elevators may be called upon to carry furniture. ESCALATORS Escalators are a very efficient form of vertical transportation for very heavy traffic where the number of floors served is limited, normally a maximum of five to six floors. Escalators are not usually accepted as a required exit. Moving passenger conveyors are particularly useful in transportation terminals, sports arenas, and exposition centers where large numbers of people must move long distances horizontally. The conveyors may be arranged in any combination of horizontal runs and inclines with a practical maximum of 12°. It is generally not economical to provide moving sidewalks for distances of less than 100 ft (30.5 m); for distances greater than 300 ft (91.4 m), as their slow operating speed invokes passenger frustration. Narrower 26-in. (660-mm) units accommodate one adult; 40-in. (1,016-mm) widths allow for both walking and standing passengers. DURABILITY Elevator cars are some of the most heavily trafficked areas in commercial interiors. Therefore, the materials used in elevators must be as durable and tamper resistant as possible. Floor material selection should consider eventual replacement. The standard floor recess is 1/2 in. (13 mm). Hard-surface materials, including tile, terrazzo, and thinset stone, can be used with high initial cost but very high durability. Vinyl composition tile (VCT) is often used in cars requiring high durability and low cost, such as in parking garage elevators; linoleum may be a more environmentally acceptable alternative. Diamond-plate metal flooring is a good option for freight elevators due to its hard surface and almost indestructible nature. Carpet is the most widely used flooring material in elevator cars because of its capability to dampen sound and its comfort underfoot; moreover, it has a relatively low initial cost when compared to stone, tile, or terrazzo. Carpet in an elevator requires replacement nearly once every six months in areas subject to high traffic. LIGHTING The lighting for elevator cars requires particular attention, because these are close environments where people, usually strangers, have to stand fairly close to one another for up to two minutes. Too much bright light is unflattering to skin and makes Contributors: Karen Gunsul, AIA, Zimmer Gunsul Frasca Partnership, Seattle, Washington. John A. Tornquist Jr., CEI, Lerch Bates and Associates, Inc., Snohomish, Washington. people psychologically uncomfortable in such close quarters. To prevent this discomfort, good lighting design requires a balance between having the elevator cab bright enough so that passengers can see into the elevator and feel safe entering it, yet low enough to soften the view within the space. The light levels in elevators do not need to be as bright as in an office environment or a hotel corridor. Minimum car lighting is 5 footcandles (50 lux) measured at the car sill. Studies show that using a standard parabolic-type lens fixture in the car ceiling is not a good lighting solution. The lighting level, while meeting the minimum 5-footcandle (50-lux) requirement, is not enough to adequately illuminate the floor. The result, when the car door opens, is that it can look dark, as if the lights in the car had been turned off and the elevator is out of commission. Placing fixtures that wash the walls of the car with light avoids this problem. A balance of downlighting and sidelighting creates the best environment. Providing a soft wash of light along the walls gives a nice reflected light on the passengers and highlights the handrail, giving focus and sparkle to the car interior. The lights remain on in many cars much of the time, so low-voltage lighting is a good idea for energy savings. Any exposed lamps, whether fluorescent or incandescent, must be shielded to prevent broken glass falling on passengers below. Finally, lamps in elevator cars must be easily accessible when it comes time to replace them. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 229 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 229 ESCALATOR PROFILE 7.500 ESCALATOR DIMENSIONS NOMINAL ESCALATOR WIDTHS SYMBOL DESCRIPTION 32 (813 MM) 2-9 to 2-10-1/8 (838 to 864 mm) 40 (1,016 MM) 48 (1,219 MM) 3-4-7/8 to 3-5-7/8 (1,038 to 1,064 mm) 4-3/4 to 4-1-11/16 (1,238 to 1,262 mm) A Centerline to centerline of handrail B Nominal step width 24 (610 mm) 32 (813 mm) 40 (1,016 mm) C Wellway rough opening 3-11-1/4 to 4-1-1/16 (1,200 to 1,251 mm) 4-7-1/8 to 4-8-7/8 (1,400 to 1,445 mm) 5-3 to 5-4-5/8 (1,600 to 1,641 mm) T Working point (WP) to end of lower truss 7-1/2 to 7-8-3/4 (2,146 to 2,356 mm) Same Same U Top of handrail 3-3-3/8 (1,000 mm) Same Same V Depth of lower pit 3-5-5/8 to 4-0 (1,057 to 1,219 mm) — — W Top of handrail 2-7 to 2-10-1/8 (787 to 867 mm) Same Same X Depth of truss 2-11-3/8 to 3-2-11/16 (899 to 983 mm) Same Same Y Depth of upper pit 3-3-3/4 to 3-5-5/8 (1,010 to 1,057 mm) Same Same Z Working point (WP) to end of upper truss 8-2-1/2 to 8-5 (2,502 to 2,565 mm) Same Same 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 230 I N T E R IO R CO NST RU CTION WHEELCHAIR LIFTS Wheelchair lifts are suitable for retrofits of buildings that are not barrier-free. Lifts are generally permitted as part of an accessible route in alterations to existing buildings. Verify applicable regulations before selecting a specific type of lift. Lifts are not generally permitted to be used as part of an accessible means of egress in new construction; therefore, in nonsprinklered buildings, horizontal exits or areas of refuge may be required in spaces served by lifts. When lifts are used in new construction, accessible means of egress may be required from the spaces served by the lifts. Lifts are generally permitted to be used as part of an accessible route in new construction only to reach performing areas in assembly occupancies, wheelchair spaces in assembly occupancies, spaces not open to the public with an occupant load of no more than 5, and spaces within a dwelling unit. Page 230 BUILDING SERVICES INCLINED WHEELCHAIR LIFT REQUIREMENTS 7.503 TYPICAL RESIDENCE PRIVATE RESIDENCE 42 (1,067 mm) high self-closing door: solid construction, mechanical/electrical interlock, lower landing 36 (914 mm) high self-closing door: solid construction, mechanical/electrical interlock, upper landing 42 (1,067 mm) platform side guard: not used as exit; solid construction 36 (914 mm) high platform side guard: not used as exit; solid construction 6 (152 mm) guard: permitted in lieu of side guard 6 (152 mm) guard: permitted in lieu of side guard 6 (152 mm) retractable guard: to prevent wheelchair rolling off platform 6 (152 mm) retractable guard: to prevent wheelchair rolling off platform Door required at bottom landing Underside obstruction switch bottom landing Travel: three floors maximum Travel: three floors maximum Push-button operation by rider Push-button operation by rider CHAIR LIFT 7.504 STAIR LIFT OR PLATFORM (STRAIGHT RUN) 7.505 TYPICAL VERTICAL WHEELCHAIR LIFT 7.501 WHEELCHAIR LIFT 7.502 NOTE 7.504 The compact size of this chair lift may make this lift type more feasible than others for residential use. Contributor: Alan H. Rider, AIA, DMJM, Washington, DC. Eric K. Beach, Rippeteau Architects, PC, Washington, DC. Wilkinson Company, Inc., Stow, Ohio. Cutler Manufacturing Corporation, Lakeland, Florida. Mark J. Mazz, AIA, Hyattsville, Maryland. STAIR LIFT OR PLATFORM—SIDE ELEVATION 7.506 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 231 BUILDING SERVICES DUMBWAITERS Dumbwaiters are small elevators typically used for conveying material in both commercial and residential applications. Capacity is determined by the maximum weight of the contents to be transported and the size of the dumbwaiter car. Maximum capacity is 500 lb (227 kg). Normal speed is 50 ft (15.2 m) per minute. The car platform may not exceed 9 sq ft (0.84 sq m). Car heights may not exceed 4 ft (1.2 m). Machines may be located above, below, or adjacent to the hatchway. Drum-type machines have a maximum rise of 35 to 40 ft (10.7 to 12.2 m); traction-type machines have unlimited range of travel. DUMBWAITER 7.507 CAPACITY, LB (KG) Buildings also affect our water supply when they endanger wetlands. Runoff from pavement and buildings interferes with the natural cycle that returns precipitation to the ground for purification and reuse. 18 (457 mm) 18 (457 mm) 24 (610 mm) 25 to 75 (11 to 34) Designers and architects should consider the following: 20 (508 mm) 20 (508 mm) 30 (762 mm) 100 (45) 28 (711 mm) 24 (610 mm) 36 (914 mm) 150 to 250 (68 to 113) DUMBWAITER CAR SIZE AND CAPACITY 7.508 WIDTH DEPTH HEIGHT 32 (813 mm) 30 (762 mm) 42 (1,067 mm) 300 to 350 (136 to 159) 36 (914 mm) 36 (914 mm) 48 (1,219 mm) 400 to 500 (181 to 227) PLUMBING SYSTEMS CONSIDERATIONS A plumbing system is used to safely transfer liquids and gases to and from a building and its site. Water supply, plumbing fixtures, and waste piping may be the most common type of plumbing system within a building, but other types of plumbing systems may be required, including plumbing for gas service, and, depending on the facility type, services such as medical gases in a hospital. Determining the fixture count, space requirements, and location of toilet rooms within the building should be an early planning consideration of the design team. Other issues that should be considered in the design of the facility plumbing system include the control of noise, vibration, and piping condensation. The potential flow of unhealthy and dangerous sewer gases back into the building requires the use of water-filled traps at each fixture, as well as a system of venting to open air. There are code requirements for the location of exterior vent openings. Plumbing fixtures provide the most visible design elements in this system; they are the parts of the building that occupants actually touch and feel. Most other plumbing components are concealed within the building construction. WATER SUPPLY SUSTAINABILITY The quality and quantity of clean water available for building use is a major environmental issue. Decreases in water supplies have already affected residents of the southwestern United States. Clean water is unavailable to many of the world’s people, and is predicted to become even scarcer in the near future. Less than 2% of the earth’s water is fresh and available for use in groundwater, lakes, and rivers. Six times the amount of water is used today than a century ago, and population demands are expected to continue to grow. Climate change affects water quantity as patterns and intensity of precipitation change, and floods and droughts increase. Rising sea levels increase saltwater intrusion into freshwater supplies, and increased precipitation leads to runoff of toxins and pollutants. Drought and temperature increases raise the demand for water for irrigation and livestock use. Water and energy use are related. Water treatment and wastewater plants use energy to process and transport water used in buildings. In addition, water is used to extract, refine, and process fuels and run energy-producing equipment. Manufacturing requires water to produce building products and interior finishes and furnishings. Although we do not need to, we use expensive and energy-intensive drinking-quality (potable) water to flush wastes out of buildings. Contributors: Eric K. Beach, Rippeteau Architects, PC, Washington, DC. Atlas Elevator Company, Chicago, Illinois. INTE R I O R CO N ST RU CT I O N 231 • Specify ultralow-flow faucets with aerators and automatic shutoff sensors. • Specify toilets that meet or exceed Energy Policy Act of 1992 (EPAct) specifications. • Specify waterless urinals. CODES AND STANDARDS Plumbing codes establish minimum acceptable standards for the design and installation of plumbing systems and the selection of the components they comprise. Requirements for plumbing system design should be based on the adopted code of the jurisdiction of the project. Tables and charts provided in this chapter are for preliminary planning purposes and should not be used for actual design. TOILET ROOMS The spacing and location of plumbing fixtures and toilet rooms should respond to occupant needs and code requirements. The design professional should be aware of how water is piped to plumbing fixtures and how waste is plumbed from fixtures, along with general venting requirements. Additional design issues needing to be considered include coordination of plumbing fixture location with toilet compartments and urinal screens, toilet and bath accessories, and tub and shower doors. ACCESSIBILITY Dimensional criteria for this section on accessible toilet rooms are based on the 2010 ADA Standards for Accessible Design and on adult anthropometrics except as noted. In new construction, all public and common-use toilet rooms are generally required to be accessible. Where multiple single-user toilet rooms or bathing rooms are clustered in a single location, no more than 50%, of the rooms for each use at each cluster must be accessible. The accessible room(s) must be identified by appropriate accessible signage where all rooms are not accessible. Single-user toilet and bathing rooms provided within a private office are permitted to be adaptable, rather than fully accessible. Replacement of the water closet and lavatory, changing the swing of the door, and installing grab bars in previously reinforced walls are steps permitted to make the room accessible. Doors in accessible toilet compartments are not permitted to swing into the required clear floor space at any fixture, except in singleuser rooms, where a clear floor space is provided beyond the swing of the door. Where toilet compartments are provided, at least one must be wheelchair accessible. Where six or more toilet compartments and urinals are provided in a toilet room, in addition to the wheelchairaccessible compartment, a 36 in. (914 mm) wide ambulatoryaccessible compartment is required for persons who can walk short distances or with assistance. Toe clearance 9 in. (229 mm) high and 6 in. (152 mm) deep is required at the front and at least one side of accessible toilet compartments. Toe clearance is not required when the compartment size exceeds the minimum dimension by 6 in. (152 mm) or more. Left- or right-handed configurations are permitted. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 232 I N T E R IO R CO NST RU CTION WOMEN’S TOILET ROOM WITH OPEN VESTIBULE 7.509 Source: Bobrick Washroom Equipment, Inc., North Hollywood, California. Page 232 BUILDING SERVICES 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 233 BUILDING SERVICES MEN’S TOILET ROOM WITH DOUBLE OPEN VESTIBULE 7.510 Source: Bobrick Washroom Equipment, Inc., North Hollywood, California. LOCATION OF ACCESSIBLE FIXTURES AND ACCESSORIES 7.511 NOTE 7.511 The particular configuration of clear floor space affects the maximum and minimum heights of the controls. If the partition is greater than or equal to 2 ft (610 mm) deep, the urinal clear floor space must be 3 ft (914 mm) wide. If the partition is less than 1 ft 5 in. (430 mm) deep, it may be 29 in. (737 mm) wide. INTE R I O R CO N ST RU CT I O N 233 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 234 I N T E R IO R CO NST RU CTION Page 234 BUILDING SERVICES TOILET COMPARTMENTS 7.512 UNISEX TOILETS The 2010 ADA Standards for Accessible Design allow the use of unisex (or single-user) toilet rooms in alterations when technical infeasibility can be demonstrated. Unisex rooms must be located in the same area and on the same floor as the existing inaccessible facilities. SINGLE-USER TOILET ROOM—OUT-SWING 7.513 SINGLE-USER TOILET ROOM—RECESSED SINK 7.515 SINGLE-USER TOILET ROOM—IN-SWING 7.514 SINGLE-USER TOILET ROOM — T-SHAPED TURN SPACE 7.516 Unisex toilet rooms are very helpful to a person with a personal care assistant of the opposite sex, and the 2010 ADA STandards for Accessible Design encourage their use in addition to accessible single-sex toilet rooms in new facilities. Unisex toilet rooms may be required by some codes in certain assembly and mercantile occupancies; this requirement applies when a total of six or more water closets (or water closets and urinals) is provided in the building. Unisex facilities must be located within 500 ft (152 m), and within one floor, of separate-sex facilities. Doors to unisex toilet and bathing rooms must be securable from within the room. ACCESSIBLE TOILET ROOM LAYOUTS Some of the toilet room layouts shown are similar; variations are in the direction of the door swing and based on whether the width or depth is the more constraining dimension. Dimensions show comfortable minimums and preferred dimensions. Overall room dimensions include a 2 in. (51 mm) construction tolerance. Each layout shows the required clear floor space for the fixtures and the doors. For door maneuvering clearances, see the 2010 ADA Standards for Accessible Design for various requirements and conditions. Variables include direction of swing, direction of approach, size of door, and door hardware. Doors to bathrooms are assumed to be 36 in. (914 mm) wide, with a closer and latch for privacy. Maneuvering clearances at the base of water closets and below lavatories may vary due to fixture design. Confirm actual water closet and lavatory dimensions for other makes and models. ICC/ANSI 117.1, published by the American National Standards Institute, requires the water closet clearance to be unobstructed by lavatory or other fixtures. In order to facilitate side transfers, the 2010 ADA Standards for Accessible Design do not permit lavatories to overlap clear floor space at water closets, except in covered residential dwellings. Accessibility requirements for toilet rooms vary; check the state and local code requirements. Contributors: Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, Hyattsville, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 235 BUILDING SERVICES PAIRED TOILET ROOMS—OUT-SWING 7.517 WATER CLOSETS 7.519 RESIDENTIAL ACCESSIBILITY STANDARDS Residential bathrooms and single-use toilet rooms can be divided into two general categories: private facilities such as those located in single- or multifamily dwellings, and public or institutional facilities such as those located in nursing homes, hospitals, dormitories, or hotels. PAIRED TOILET ROOMS—RECESSED SINKS 7.518 Wheelchair bathroom standards for dwellings are included in the ICC/ANSI A117.1. 2010 ADA Standards for Accessible Design. In multifamily projects with mobility features 5% of the total dwellings must meet the ICC/ANSI or 2010 ADA Standards for Accessible Design standards for full wheelchair accessibility. ADAPTABLE BATHROOMS ICC/ANSI A117.1 defines adaptability as the capability of certain elements to be altered or added so as to accommodate the needs of persons with or without disabilities, or to accommodate the needs of persons with different types or degrees of disabilities. Some codes and civil rights laws require provisions in certain residential bathrooms for adaptable features. For single-family custom homes or remodeling projects, bathroom designs should be specially tailored to the individual homeowners. If a master bathroom is planned for a wheelchair user, for example, the design should reflect that person’s individual capabilities and preferences. MANEUVERING SPACE All of the standards permit required floor space for fixtures to overlap with required maneuvering space. 2010 ADA Standards for Accessible Design permit the bathroom door (in single-user facilities) to swing into any fixture clearance, if a clear floor space at least 30 in. by 48 in. (762 by 1,219 mm) is provided outside of the door swing. BATHROOM ENTRY DOORS ICC/ANSI and the 2010 ADA Standards for Accessible Design require installation of at least a 36-in. (914-mm) door to provide the full 32 in. (813 mm) clear opening. Contributors: Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, Hyattsville, Maryland. INTE R I O R CO N ST RU CT I O N 235 CONVENTIONAL BATHROOM LAYOUTS—NOT ACCESSIBLE 7.520 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 236 I N T E R IO R CO NST RU CTION ACCESSIBLE RESIDENTIAL BATHROOM LAYOUTS 7.521 Page 236 BUILDING SERVICES GRAB BARS 2010 ADA Standards for Accessible Design require grab bars on the side wall closest to the water closet and on the rear wall. Reinforcement must be provided for the installation of grab bars fully meeting all accessibility requirements, including length, installation height, and structural strength. Grab bar arrangement can influence the floor plan of an accessible bathroom. • Material: Stainless steel or chrome-plated brass with knurled finish (optional). • Installation: Concealed or exposed fasteners; return all ends to the wall, intermediate supports at 36 in. (914 mm) maximum. Use heavy-duty bars and methods of installation. Other grab bars are available for particular situations. Consult ICC/ANSI and ADA requirements, as well as applicable local and federal regulations. Grab bar criteria include: • Size: 1-1/2 in. (38 mm) or 1-1/4 in. (32 mm) outside diameter with 1-1/2-in. (38-mm) clearance at wall. TOILET REAR WALL GRAB BAR 7.524 TOILET SIDE WALL GRAB BAR 7.522 ADA ACCESSIBILITY GUIDELINES FOR CHILDREN’S WATER CLOSETS 7.523 DIMENSION AGES 5 THROUGH 8 AGES 9 THROUGH 12 12 (305 mm) 12 to 15 (305 to 381 mm) 15 to 18 (381 to 457 mm) Toilet seat height 11 to 12 (279 to 305 mm) 12 to 15 (305 to 381 mm) 15 to 17 (381 to 432 mm) Grab bar height 18 to 20 (457 to 610 mm) 20 to 25 (508 to 635 mm) 25 to 27 (635 to 686 mm) Dispenser height 14 (356 mm) 14 to 17 (356 to 432 mm) 17 to 19 (432 to 483 mm) Water closet centerline AGES 3 AND 4 CHILDREN’S TOILET ROOMS 2010 ADA Standards for Accessible Design consider spaces and elements specifically designed for use primarily by children to refer to people 12 years old and younger. Plumbing elements and facilities for children covered by these standards include toilet compartments, drinking fountains, lavatories and sinks, and grab bars. Grab bar heights for children are required to be a minimum of 18 in. (457 mm) and a maximum of 27 in. (686 mm) to the top of the grasping surface from the finished floor. Water closets and toilet compartments for children’s use vary depending on the size, stature, and reach ranges of children aged 3 through 12. Wheelchair accessible toilet compartments for children’s use are required to be a minimum of 60 in. (1,524 mm) wide, measured perpendicular to the side wall, and 59 in. (1,499 mm) minimum deep, measured perpendicular to the rear wall, for wall-hung and floormounted water closets. Toe clearance at the front partition is not required for children where the toilet compartment is greater than 65 in. (1,651 mm) deep. NOTES 7.521 a. ICC/ANSI Accessible refers to ICC/ANSI A117.1 accessible units. Contributors: Kim A. Beasley, AIA, and Thomas D. Davies Jr., AIA, Paralyzed Veterans of America Architecture, Washington, DC. Mark J. Mazz, AIA, Hyattsville, Maryland. Virginia A. Greene, VGA Architect, PC, Huntington, New York. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 237 BUILDING SERVICES LOCKER ROOMS AND SHOWERS SHOWER ROOM DESIGN The shower room should be directly accessible to the drying room and locker room that it serves. When a shower room is designed to serve a swimming pool, the room should be located so that all must pass through showers before reaching the pool deck. Separate wet and dry toilet areas are recommended. Wet toilets should be easily accessible from the shower room. When designed for use with a swimming pool, wet toilets should be located so that users must pass through the shower room after use of the toilets. INDIVIDUAL SHOWERS AND DRESSING ROOM PLANS 7.525 WATER SUPPLY PIPING 7.527 Contributor: BFS Architectural Consulting and Interior Design, YMCA of the USA, Chicago, Illinois. American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. TYPICAL SHOWER AND DRESSING ROOM DIMENSIONS 7.526 MINIMUM OPTIMUM Showers 3-0 3-6 (914 1,066 mm) 3-6 3-6 (1,066 1,066 mm) Dressing rooms 3-0 3-6 (914 1,066 mm) 3-6 4-0 (1,066 1,219 mm) DRYING AND WET TOILET AREA The drying room should have about the same area as the shower room. Provision for drainage should be made. Heavy-duty towel rails, approximately 48 in. (1,219 mm) from the floor, are recommended. A foot-drying bench 18 in. (457 mm) high and 8 in. (203 mm) wide is desirable. An adjacent wet toilet is suggested. Avoid curbs between a drying room and the adjacent space. The size of the towel service area (which can be used for distributing uniforms) varies with the material to be stored; 200 sq ft (18.6 sq m) is usually sufficient. INTE R I O R CO N ST RU CT I O N 237 DOMESTIC WATER DISTRIBUTION AND PIPING RESIDENTIAL PLUMBING DESIGN Observe the following guidelines when designing plumbing for a residence: 1. Do not exceed the number of drainage fixture units (DFUs) allowed in a pipe. 2. The inside diameter of piping within and below a poured concrete floor cannot be less than 2 in. (51 mm). 3. Polyvinyl chloride (PVC) and acrylonitrile butadiene styrene (ABS) piping transmit water noise, so they should not be used above areas such as a dining room or living room. For these areas, consider cast-iron piping, which is quieter. 4. Minimize the use of 1-1/4 and 1-1/2 in. (31 and 38 mm) pipe as drain line pipe, even if allowed by code. Such pipe, over the long term, tends to clog, especially when used as a kitchen drain. 5. Maintain the pitch of the pipe at 1/4 in./ft (6 mm/305 mm) minimum. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 238 I N T E R IO R CO NST RU CTION PLUMBING FIXTURES A plumbing fixture is a device or appliance that is designed to supply water or receive waterborne waste, and may discharge into a sanitary waste system. Ideal fixture materials should be nonabsorbent, nonporous, nonoxidizing, smooth, and easy to clean. Plumbing codes usually mandate the number and type of fixtures that must be provided for specific occupancy based on the capacity. Provisions for people with disabilities have been made an integral part of code requirements mandating the quantity and design of spaces utilizing plumbing fixtures. TYPICAL PLUMBING FIXTURE WATER SUPPLY AND DRAINAGE 7.528 Page 238 BUILDING SERVICES Off-the-floor plumbing fixtures are often preferred because installation is done at the floor; floor-mounted installation is done at the ceiling below the fixture, making it more labor intensive. Because the waste piping is horizontal, the number of core drills required is reduced. In addition, cleaning costs are lower. A standard 3-1/2 in. (89 mm) wide partition may not be wide enough to support common plumbing fixtures such as lavatories, sinks, and drinking fountains. Placement of pipes prior to construction of the partition may not have been within required tolerances, or a structural member might be located beneath the chase. There may be additional plumbing fixtures on the same wall, or the supply pipes for fixtures may serve other floors. WATER CLOSETS Water closets, urinals, and bidets generally have two parts: a receptor for waste, which includes the drain trap, and a flushing or water supply mechanism. Most are made of vitreous china. These plumbing fixtures are generally grouped according to their flushing action, which affects the bowl type, flushing mechanism, and mounting method. Special toilet types are sometimes used, such as vacuum vented, composting, and chemical toilets. FIXTURE FLUSHING ACTION TYPES Current code requires that water closet flush valves and tanks be limited to 1.6 gal (61 L), maximum, per flush of water. One way to meet this requirement is with an exposed, battery-powered, sensor-activated electronic dual-flush water closet flushometer for floor-mounted or wall-hung bowls. When installing some electronic flushometers in handicapped accessible stalls, the manufacturer may recommend that grab bars be split or shifted to the wide side of the stall. PLUMBING FIXTURE COUNTS 7.529 FACILITY TYPE NUMBER OF PEOPLE Stadiums, arenas, convention halls, terminals 1 to 100 1 101 to 200 2 Churches, auditoriums, theaters Restaurants Sports clubs, country clubs Stores, malls, office buildings Dormitories FIXTURE COUNTS Guidelines for the number of fixtures required include the following: • In stores, malls, and office buildings, if employee facilities are available for customer use, no additional lavatory fixtures are necessary. • Sports clubs and country clubs require one shower for each 40 persons up to 150, and an additional one shower for each 30 people over 150. • Some codes require double or triple the number of water closets for women in stadiums, arenas, convention halls, and terminals. The same is true for churches, auditoriums, and theaters. Consult local plumbing codes for exact requirements. • Stores, malls, and office buildings with 16 to 75 employees are required to have a minimum of one service sink per floor. • Dormitories are required to have one laundry tray for each 20 people. FIXTURE SUPPORTS When a floor-mounted support cannot be installed, wall-mounted supports can be used if the wall structure is strong enough to support the entire weight of the fixture. In such installations, the support arms are attached to a plate that is bolted directly into the wall structure. Wall support is not necessary when the fixture is freestanding. NOTES 7.529 a. Some plumbing codes permit half of the required water closets to be urinals. Verify local code requirements. b. Some plumbing codes permit half of the lavatories required to be water closets. Verify local code requirements. Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. WATER CLOSETS 201 to 400 4 Additional 300 1 1 to 50 1 51 to 300 2 Additional 300 1 1 to 50 2 51 to 100 3 101 to 200 4 Additional 200 1 1 to 40 1 Additional 40 1 1 to 15 employees 1 16 to 40 employees 2 41 to 75 employees 3 Additional 60 employees 1 1 to 15 customers 1 16 to 40 customers 2 41 to 75 customers 3 Additional 60 customers 1 1 to 20 2 LAVATORY, TOILET, AND URINAL MOUNTING HEIGHTS 7.530 DRINKING FOUNTAINS 1/1,000 people 1/1,000 people 1/200 people 1/75 people 1/100 employees 1/1,000 customers — 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 239 BUILDING SERVICES ONE-PIECE TOILET 7.531 TWO-PIECE TOILET 7.532 INTE R I O R CO N ST RU CT I O N 239 WALL-MOUNTED TOILET 7.533 Source: Duravit AG. HIGH-EFFICIENCY TOILET—FLOOR MOUNTED 7.534 Source: Duravit AG. Source: Duravit AG. Source: Sloan Valve Company. Contributors: Nader Dubestani, PE, Sazan Group, Inc., Bellevue, Washington. American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 240 I N T E R IO R CO NST RU CTION Page 240 BUILDING SERVICES HIGH-EFFICIENCY TOILET—WALL MOUNTED 7.535 WALL-HUNG WATER CLOSET PLUMBING CHASE SIZES 7.537 Source: Sloan Valve Company. BACK-TO-BACK TOILET FIXTURES 7.538 MOUNTING TYPES AND CLEARANCES Water closet flush valves and tanks can be installed on either floormounted or wall-mounted water closets. For rough-in dimensions for water supply and sanitary waste, refer to the fixture manufacturer. WATER CLOSET MOUNTING TYPES 7.536 BIDETS AND WASHLETS A bidet is a low, basin-like plumbing fixture designed to be straddled, for bathing the posterior of the body. It is often designed to sit next to the water closet. Although a bidet looks something like a toilet, it functions more like a washbasin or bathtub. Bidets are nearly universal in Arabic countries, popular in southern Europe, and common in some parts of Latin America, North Africa, and Asia. They are less well known in North America. In the 1980s, paperless toilets were introduced in Japan. Called washlets, these combination toilets and bidets are designed to dry the user after washing. They are often equipped with seat warmers. Toilet seat and bidet units are also available for converting existing toilets. Washlets can be helpful to people with limited mobility. Special units with higher toilet bowls benefit persons using wheelchairs. Electronic remote controls are also available. BIDET 7.539 NOTE 7.537 Flush valve, fixture support independent of wall, horizontal waste arrangement with no-hub cast-iron pipe. Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. Jacqueline Jones, American Standard, Piscataway, New Jersey. Philip Kenyon, Kohler, Kohler, Wisconsin. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 241 BUILDING SERVICES URINALS Urinals require flush valves as the source of the water supply. Install urinals 21 to 24 in. (533 to 610 mm) on center, except for accessible urinals. If used, urinal tanks should be 92 to 94 in. (2,337 to 2,388 mm) above the floor. Stall-type urinals are more easily accessed by a broader range of persons, including those of short stature. ADA/ABA Accessibility Guidelines 2004 for urinals require that the rim of either stall-type or wall-hung urinals be a maximum of 17 in. (430 mm) above the finish floor. The minimum depth from the outer face of the urinal rim to the back of the fixture is 13-1/2 in. (345 mm). Clear floor space positioned for forward wheelchair approach is required. Either hand-operated or automatic flush controls that meet the 2010 ADA Standards for Accessible Design are acceptable. Waterless, touch-free urinals do not require supply plumbing, but do require a wall outlet. They use proprietary technology, such as a biodegradable sealant liquid in a replaceable sealed locking cartridge, to provide odor-free removal of urine to waste plumbing. According to the 2010 ADA Standards for Accessible Design, men’s toilet rooms with only a single urinal are not required to have an accessible urinal, but are required to provide an accessible toilet compartment. INTE R I O R CO N ST RU CT I O N 241 Lavatories often have a raised back ledge that serves as a backsplash; deep ledges may serve as a shelf. They may be mounted on brackets or concealed arms. Exposed arm fixture supports are typically used with vitreous china lavatories. When using lavatories of the flat-slab type (i.e., without a backsplash), manufacturers typically require a space of 2 to 6 in. (51 to 152 mm) between the wall finish and the rear of the lavatory to prevent water accumulation. EXPOSED ARM FIXTURE SUPPORT 7.543 URINAL PLUMBING CHASE 7.541 URINALS 7.540 LAVATORIES AND SINKS Lavatories have a shallow receptor designed primarily for washing hands, arms, and face; sinks are generally deeper and designed for general washing and disposal of liquid waste. Sinks can include residential, commercial, and service applications. Lavatories are generally one of three types: wall hung, installed in or as part of a countertop, or pedestal. Vitreous china is the most common material used in lavatories, though they are also available in cast acrylic resin and enameled cast iron, enameled steel, stainless steel, and other metals. Sink materials include stainless steel, enameled iron or steel, and cast resin. The underside of stainless steel sinks typically is coated with a sound-deadening material. Sink accessories may include pull-out faucets, instant hot or chilled water dispensers, soap dispensers, and garbage disposers. WALL-HUNG LAVATORIES Wall-hung lavatories are available in many sizes, shapes, and designs; exact dimensions and design will vary by manufacturer. WALL-HUNG LAVATORY PLUMBING CHASE SIZES 7.542 NOTES 7.541 Wall hung, flush valve, fixture support independent of wall, horizontal waste arrangement, no-hub cast-iron pipe. 7.542 Fixture support independent of wall, no-hub cast-iron pipe. Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. Jacqueline Jones, American Standard, Piscataway, New Jersey. Philip Kenyon, Kohler, Kohler, Wisconsin. WALL-HUNG SERVICE SINK 7.544 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 242 I N T E R IO R CO NST RU CTION Page 242 BUILDING SERVICES LAVATORY SPACE REQUIREMENTS 7.549 WALL-HUNG LAVATORIES 7.545 WASH AND SERVICE SINKS Hand-washing sinks are used in food service and other facilities. Stainless steel hand-washing sinks are available with infrared (IR) sensors that turn water flow on and off when a person’s hands are detected. Industrial wash sink materials include stainless steel, terrazzo, and cast resin. Most sinks have foot controls; some have hand controls or sensors. Water is supplied from above, below, or through the wall. Floor service sinks are available in stainless steel and terrazzo. ACCESSIBLE LAVATORIES Exposed pipes and water supply pipes located beneath accessible lavatories must be insulated or located so as to protect users from contact. The FHAA does not require knee space, but the other standards do. BUILT-IN LAVATORIES Built-in (drop-in) lavatories come in a variety of sizes and shapes, typically oval, rectangular, or circular. Built-in sinks may include single-, double-, and triple-bowl sinks. More specialized fixtures include corner bowl sinks, and units with integral drainboards. Drainboard areas may be used with single-, double-, and triple-bowl sinks. Institutional kitchen sinks may have longer drainboards. Consult manufacturers for exact dimensions, configurations, and options. PEDESTAL LAVATORY 7.547 ACCESSIBLE FAUCETS The 2010 ADA Standards for Accessible Design require faucets and other operable parts to be accessible from a clear floor space, and placed within reach ranges specified. They must be operable with one hand, and without tight grasping, pinching, or twisting of the wrist. The force required to operate the controls is limited to 5 lb (22.2 N) maximum. Hand-operated metering faucets are required to remain open for at least 10 seconds. Both lavatories and sinks may be self-rimming, where the rim is integral to the unit; rimless units are available for undercounter installations. Lavatory bowls may also be mounted on top of a countertop, although this is typically a residential application. Builtin lavatories and sinks may meet building code requirements for accessibility if placed in an accessible counter. ADA-compliant lavatory faucets are available with electronic controls, including ones with light-emitting diode (LED) color temperature indicators. Sensor-controlled faucets obviate the need for hand operation. PEDESTAL LAVATORIES Pedestal lavatories may be either wall mounted or freestanding. Consult manufacturers for specific designs, forms, and dimensions. BUILT-IN LAVATORY 7.546 Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. Mark J. Mazz, AIA, Hyattsville, Maryland. Lawrence G. Perry, AIA, Silver Spring, Maryland. All accessibility standards except the FHAA standards include requirements for a maximum sink depth. 2010 ADA Standards for Accessible Design and ANSI also include requirements for faucets, mirrors, and medicine cabinets. ACCESSIBLE LAVATORY 7.548 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 243 BUILDING SERVICES BATHTUBS Bathtubs are available in many shapes and installation types, and are made of the following materials: Fiberglass: An economical and common choice, gel-coated fiberglass (also known as fiber-reinforced plastic [FRP]) is lightweight and easy to install. A polyester gel coat is a pigmented coating that is applied to the inside surface of a mold, becoming an integral part of the finished piece. Because the material can be molded, fiberglass bathtubs are available in a variety of shapes. Although not as durable as cast iron or acrylic, fiberglass can easily be repaired. Acrylic: Acrylic bath fixtures are usually reinforced with fiberglass. Because acrylic is light and easily formed into different shapes, it is a good choice for whirlpools and other large tubs that would be too heavy in cast iron. Acrylic also is a good insulator and thus keeps the water warmer longer. Cast iron: Very heavy and extremely durable, traditional enamel-coated cast iron resists staining and scratching. It cannot be molded as freely as acrylic or fiberglass, so there are fewer shapes and styles from which to choose. Enameled steel: This is a lighter-weight, less expensive alternative to cast iron. Built-in bathtubs have an integral apron and tiling flange, for installation in a three-wall alcove. Drop-in designs are intended for deckmounted installations and typically have integral feet that support the weight of the unit. Many whirlpool bathtubs are drop-in units, although manufacturers may offer built-in units with a removable apron for access to the pump. power (0.4 to 2.2 kW), and the intensity of the flow varies accordingly. In-line heaters are recommended to keep the water warm without refilling the tub. DROP-IN WHIRLPOOL BATHTUB 7.552 The bathtub clear floor space requirements are similar to those for water closets in that an approach direction is indicated (either perpendicular or parallel). FHAA offers two different clear-space requirements; the designer may choose to comply with either. Of these alternatives, Alternate B is stricter because it requires clear space adjacent to the foot of the tub. Tub enclosures must not obstruct controls, interfere with transfer from a wheelchair to the tub, or have tracks mounted on the tub rim. For tubs with a built-in seat at the head of the tub, the seat must be 15 in. (381 mm) wide, and clear floor space must be provided in front of the seat. CERAMIC TILE TUB ENCLOSURE 7.553 FREESTANDING BATHTUB WITH LEGS 7.550 ACCESSIBLE BATHTUBS 7.554 Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. Mark J. Mazz, AIA, Hyattsville, Maryland. Lawrence G. Perry, AIA, Silver Spring, Maryland. Tile Council of America, Inc., Anderson, South Carolina. Whinnie Cheng, Rhode Island School of Design, Providence, Rhode Island. Jess McIlvain, AIA, CCS, CSI, Jess McIlvain and Associates, Bethesda, Maryland. ACCESSIBLE BATHTUBS Bathtub controls, other than drain stoppers, must be located on an end wall between the tub rim and grab bar and between the open side of the tub and the midpoint of the tub width. A 59 in. (1,499 mm) minimum length shower spray unit is required. In whirlpool bathtubs, air mixed with water streams through jets in the side of the tub, giving the whirlpool its soothing, therapeutic character. Models may have 3 to 10 jets, including some aimed to massage feet, back, and neck. Jet direction can usually be adjusted; some jets can also be adjusted to deliver a pulsating or steady stream or to regulate intensity. Pumps range from 1/2 to 3 horse- BUILT-IN BATHTUB 7.551 INTE R I O R CO N ST RU CT I O N 243 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 244 I N T E R IO R CO NST RU CTION SHOWERS Materials for shower bases include acrylic with fiberglass reinforcement, enameled steel, and terrazzo. They may be manufactured units or built on-site. Page 244 BUILDING SERVICES SHOWER RECEPTOR CONSTRUCTION 7.557 COMMON SHOWER SIZES AND CONFIGURATIONS 7.559 Chrome-plated showerheads are available in a variety of finishes. Volume controls adjust the flow to a maximum of 2.5 gal/min (9.4 L/min) to conserve water. The 2010 ADA Standards for Accessible Design require that shower spray controls have an on/off control and deliver water no hotter than 120 degrees F. TYPICAL SITE-BUILT SHOWER CONSTRUCTION 7.555 MANUFACTURED ONE-PIECE SHOWER STALL 7.558 SHOWERHEAD AND CONTROL HEIGHTS 7.560 SHOWER RECEPTORS 7.556 ACCESSIBLE SHOWERS Accessible showers include both transfer stalls (where a bather moves from a wheelchair to a bench or portable seat) and roll-in stalls (where a bather remains seated in a special shower chair and is either pushed by an attendant or self-propelled into the stall). All accessibility standards require either wall reinforcing or grab bars inside a shower. Seats may be fixed or foldable. Requirements that apply to accessible showers include: • Shower compartment thresholds are not generally permitted to exceed 1/2 in. (13 mm). The design should anticipate water escaping from the compartment. • A fixed, folding, or removable seat is required in transfer-type compartments. Seats in roll-in showers, where provided, should be located on the wall adjacent to the control wall, and should be folding-type seats. Seats can be rectangular or L-shaped; see ICC/ANSI A117.1 for details. Contributors: Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, Hyattsville, Maryland. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 245 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 245 Treatment can be carried out either by a public utility or on-site with a private treatment plant approved by the local jurisdiction. ACCESSIBLE SHOWERS 7.561 The building drain is the lowest portion of the drainage system inside a building; it is the main line that carries effluent outside the building. The building sewer is a continuation of the building trap that runs from outside the building to the point of disposal. A stack is a vertical pipe more than three stories high. A branch line is any drainage line connecting to a stack or the building drain. In the absence of public sewers, a private sewage disposal system must be provided. The most commonly used is a facility septic tank, which depends on bacterial action to change most solids into a liquid, which is then discharged into an underground absorption field. The basic principle is to have the volume of effluent conditioned by the septic tank and the discharge from the tank absorbed into the ground as quickly as it is discharged. Laundry appliances should be routed to separate dry wells, because the soap and other chemicals retard or stop bacterial action in a septic tank. Grease should be disposed of separately. • A 59 in. (1,499 mm) minimum length shower spray unit is required. • Shower enclosures, where provided, must not obstruct controls or interfere with transfer from a wheelchair. • In transfer-type showers, ICC/ANSI A117.1 requires a vertical grab bar on the control wall a minimum of 18 in. (457 mm) long, and 3 to 6 in. (76 to 151 mm) maximum above the horizontal grab bar. The horizontal grab bar is 4 in. (102 mm) maximum inward from the front edge of the bathtub. Other regulations may not have these requirements. DRAINAGE AND VENT PLUMBING 7.562 Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. Lawrence G. Perry, AIA, Silver Spring, Maryland. Mark J. Mazz, AIA, Hyattsville, Maryland. SANITARY WASTE DRAINS AND VENTS Sanitary waste systems convey waterborne effluent from plumbing fixtures and other equipment to an approved point of disposal that discharges into a facility sanitary sewer. The sanitary sewer system receives all liquid waste (sanitary waste) except storm water or unacceptably treated process or chemical waste. Effluent that contains bodily waste is referred to as soil. Clear water waste, such as that from equipment, sinks, or showers, is referred to as waste. Untreated waste containing chemical effluent must be treated before discharge into the sewer system or the environment. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 246 I N T E R IO R CO NST RU CTION TYPICAL CLEANOUT INSTALLATION 7.563 Page 246 BUILDING SERVICES DECORATIVE WATER FEATURES INTERIOR FOUNTAINS Although interior fountains can be built with concrete or flexible membrane pool bases, prefabricated fountain systems with fiberglass pools are easier to work with. Fiberglass pools are available with dimensions from 4 to 24 ft (1.2 to 7.3 m) in an almost unlimited variety of standard and custom shapes. Pools up to 8 ft (2.4 m) in diameter can be shipped ready to install; larger sizes must be assembled before installation. Pools can be installed on a level substrate, raised above grade, or recessed below the surface. Pool components include, at a minimum, a pump, a light source, and a nozzle. Typically, equipment includes a nozzle manifold, manual control valves, a junction box with penetration kit, and a control panel. More elaborate components can include multiple pumps for animated and musical systems. The appearance of the fountain’s spray depends on whether the nozzle produces a clear stream or an aerated spray, and whether the nozzle is level dependent or independent. WATERFALL SYSTEMS There are many types of manufactured waterfalls available, including: FIXTURE TRAPS A fixture trap is a U-shaped section of pipe that is deep enough to prevent the passage of sewer gas into a fixture. All fixtures directly connected to the sanitary drainage system must be trapped and vented, unless waived by local codes. Traps must be capable of draining a fixture rapidly, be self-cleaning, and have an accessible cleanout. They must provide a liquid seal of at least 2 in. (51 mm), or larger when required, and conform to local code requirements regarding minimum size. TYPICAL PLUMBING FIXTURE TRAP 7.564 VENT PIPING The purpose of a vent system is to equalize the pneumatic pressure (both positive and negative) within a facility sanitary sewage system to plus or minus 1 in. (25 mm) of water column. Vent systems terminate in the outside air and connect indirectly to every fixture trap. Each individual fixture vent must rise above the flood level of the fixture served before being connected to another vent line, so as not to act as a waste line in the event the drain line becomes blocked. Contributors: American Society of Plumbing Engineers, Westlake, California. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. • Freestanding waterfalls that may be completely self-contained, without a water line or drain • Translucent waterfalls with tempered, patterned, colored, cast, or textured glass on both sides of cascading water • Seamless water panels that can be used as surfaces for lightprojection of logos, images, or messages • Built-in water features set into walls as focal points • Custom-finished water panels with lighting, mechanical, and water purification equipment concealed by finishes • Three-dimensional waterfalls in many custom forms, including stainless steel columns, granite towers, and glass-walled structures TYPICAL INTERIOR DRINKING FOUNTAINS 7.565 DRINKING FOUNTAINS AND WATER COOLERS Drinking fountains (DFs) only use water at ambient temperatures; electric water coolers (EWCs) use an integral or remote chiller to cool water for drinking. Design guidelines include: • Use air-cooled condensers for normal room temperatures and water-cooled units for high room temperatures and larger capacities. Many models are available with hot and cold water supplies, a cup-filling spout, or refrigerated compartments. • Install half of the required fountains or water coolers as accessible, but design the layout so accessible fountains do not obstruct movement of the visually impaired. • Consult local building codes for the number of drinking fountains or water coolers required. The 2010 ADA Stndards for Accessible Design for drinking fountains include the following: • Clear floor space centered on the unit is required for a forward approach. • A parallel approach is permitted at units for children’s use where the spout is 30 in. (762 mm) maximum above the finish floor and 3-1/2 in. (89 mm) maximum from the front edge of the unit, including bumpers. • Toe and knee clearances are also required. • The spout outlet height is required to be 36 in. (914 mm) maximum above the finish floor, with the spout located 15 in. (381 mm) minimum from the vertical support and 5 in. (127 mm) from the front edge of the unit, including bumpers. • Accessible spout fountains for standing users are required to be 38 in. (965 mm) and 43 in. (1,092 mm) maximum above the finish floor. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 247 BUILDING SERVICES The water flow of accessible drinking fountains is regulated by the 2010 ADA Standards for Accessible Design to allow a cup to be used. • Water flow for accessible drinking fountains should be at least 4 in. (102 mm) high and be located 5 in. (127 mm) from the front of the unit. • Where the spout is less than 3 in. (76 mm) from the front of the unit, the water stream angle is required to be 30° maximum. • Spouts between 3 and 5 in. (76 and 127 mm) from the front edge must have a maximum 15° water stream angle. TYPICAL INTERIOR ELECTRIC WATER COOLERS 7.566 DRINKING FOUNTAIN OR ELECTRIC WATER COOLER MOUNTING HEIGHTS 7.567 INTE R I O R CO N ST RU CT I O N 247 AQUARIUMS Aquariums, which are most commonly known for housing aquatic life, are typically larger tanks used for public, commercial, or residential applications. All aquatic enclosures must provide an environment that continually controls and monitors water quality and temperature. Primary considerations for any aquatics or aquarium facility include water and air quality. • Water quality : Whether it is municipal water, groundwater, or surface water, water quality is paramount to the survival of all species. Monitoring systems provide logging of data and alarm notification. Control systems measure and control the pH and salinity levels of the water. • Air quality : Building ventilation is important in maintaining the proper room temperature that will stabilize the water temperature of the aquatic tanks. This is crucial to preventing the growth or spread of mold and fungi, which can have a negative impact on air quality. COMMERCIAL AQUARIUMS The primary enclosure of an aquarium is a shatterproof tank. Plastic tanks are lightweight and seamless, and available in various sizes up to 60 gal (227 L) or more. Depending on the size, some aquariums are capable of being stand-alone systems that do not require building service support. Stand-alone units are provided with the pumps, tanks, filtration, and chillers required to maintain the water quality and temperature. Tanks must be capable of withstanding temperatures up to 212°F, allowing for cleaning through a cage washer and/or autoclave. STAND-ALONE SHOWCASE TANK 7.568 MECHANICAL SYSTEMS HEATING SYSTEMS SOLAR HEATING Solar heat continues to be developed as an energy source for heating buildings. Solar radiation reaches the earth’s surface in the form of electromagnetic radiation. Solar thermal collection systems can be used to provide heat for space heating, domestic (potable) water service, and/or space cooling. Of these applications, heating systems are common and cooling systems are rare. A solar heating system consists of an array of collectors, a storage subsystem, and another subsystem, generally a very conventional one, for distributing the heated fluid to points of use and returning it to storage. Pumps or fans are used to circulate the heat transfer fluid, and control devices are used to start and stop these circulators. Auxiliary or standby heat sources are generally needed to carry part of the load when demand is exceptionally heavy and/or the thermal storage is depleted due to long periods of unfavorable weather. Contributors: K. Shahid Rab, AIA, Friesen International, Washington, DC. Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey Chris Czenszak, GPR Planners, Inc., Purchase, New York. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 248 I N T E R IO R CO NST RU CTION FLAT-PLATE COLLECTORS Solar radiant energy can be put to use for low- and moderate-temperature applications with flat-plate collectors, in which a blackened sheet of metal is used to absorb the incoming radiation and convert it to heat. This heat is then conducted to a fluid that passes through tubes or passages integral with or attached to the plate. Single or double glazing of glass or a heat-resistant plastic minimizes heat loss from the absorber plate by reducing convection and suppressing longwave radiation exchange with the sky. The rear surface of the collector plate is insulated carefully, preferably with glass fiber that can withstand the relatively high temperatures (300 to 400°F) that can exist when the collector is exposed to full sunshine with no heat transfer fluid flow. The entire unit is contained within a weatherproof box, and connecting pipes or ducts are provided to bring the transfer fluid to the collector and to carry it away after it has been heated. Evacuated tube collectors are also available; these consist of assemblies of glass cylinders and can provide higher-efficiency performance TYPICAL FLAT-PLATE COLLECTOR—LIQUID COOLED 7.569 Page 248 BUILDING SERVICES than flat-plate collectors. Details of many types of solar collectors can be found in the ASHRAE Handbook—HVAC Applications. Performance test methods are given in ASHRAE standards. WARM-AIR FURNACES Warm-air furnace units are designed primarily for residential, small commercial, or classroom heating. Cooling can be added to these units by installing a cooling coil downstream from the furnace, with refrigerant compressor and condenser located remotely outside the building. A duct system from the furnace unit can be installed above the ceiling or in a furred-down soffit. Distribution systems above the ceiling are usually the radial type with high wall registers. Duct systems also may be installed below living spaces, in a crawl space, or in a basement. Two- or three-story buildings using similar warm-air furnace and cooling-coil combinations are centrally air conditioned via vertical extension of the branch ductwork through walls and partitions. All variations of warm-air heating and cooling systems recirculate their air within the building envelope, making it a crucial design requirement to leave adequate return air passage from each space supplied with air to the furnace room. HYDRONIC SYSTEMS Active heating and cooling systems for buildings use either air or water as the heat transfer medium. Heating systems that use water are referred to as hydronic systems. Cooling systems that use water are often referred to as chilled-water systems. Water is a very efficient means of transmitting heat to different areas of a building. Hot water carries almost 3,500 times more heat than the same volume of air. Compactness is the principal advantage of a hydronic system. Although varied in design, all hydronic heating systems contain the following basic components: • • • • Hot water boiler and its controls and safety devices Expansion tank, also referred to as a compression tank Water pump, also called a circulator Terminal devices that transfer heat from the circulating water to the various building spaces • Piping • Controls that regulate the system Types of hydronic heating systems are often commonly referred to by their terminal units, which include the following: • • • • • • Fin-tube radiation units Convectors Fan-coil units Radiant floor and ceiling systems Cast-iron radiators Steel panel radiators FINNED TUBE RADIATION Finned tube radiation units typically consist of a copper pipe on which are mounted square aluminum or copper fins. Hot water passes through the pipe, heating the pipe and, in turn, the fins. This finned tube assembly is installed in a metal enclosure designed to encourage convective air current over the hot pipe and fins. Cool air enters the baseboard enclosure at the bottom, is heated as it passes over the hot finned-pipe assembly, and exits the top of the enclosure to heat the space. The heated air rises, is cooled by the room’s heat loss, drops to the floor, and re-enters the finned tube radiator to be reheated. HYDRONIC SYSTEM 7.570 CONVECTORS Convectors consist of one or more vertical tiers of finned tube radiation. They differ from the finned tube radiators only in that convectors have a much larger capacity. Convector units installed on outside walls should have rear insulation to prevent significant heat loss through the wall. This is especially important for recessed convector units, because the R-value of the wall may be reduced by the recess. FINNED TUBE RADIATORS 7.571 Contributors: Walter T. Grondzik, PE, Florida A&M University, Tallahassee, Florida. John I. Yellott, PE, and Gary Yabumoto, College of Architecture, Arizona State University, Tempe, Arizona. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 249 BUILDING SERVICES CONVECTORS 7.572 RADIANT HEATING FLOOR LAYOUT 7.573 RADIANT HEATING MAT WITH CERAMIC TILES 7.574 Source: Corky Binggeli, Building Systems for Interior Designers, 2nd ed., John Wiley & Sons, Hoboken, NJ, 2010. Radiant ceiling installations are less common in commercial interiors because a blanket of heated air forms at the ceiling and remains there, which leads to a condition of stagnant air in a closed room. Overhead radiant panels are often used to heat loading docks and other partially exterior spaces that do not require a fine temperature control. FAN-COIL UNITS Fan-coil units can provide heating, cooling, or both. A fan-coil unit is essentially a cabinet containing a hydronic coil assembly and a motor-driven blower. Hot or cold water is piped to the unit. Control of the blower is often given to the user. Fan-coil units do not usually provide dehumidification. Dehumidification occurs when the room air is cooled below its dew point as it passes over the cooling coil. A condensate pan and drain line is often provided to collect and remove the condensate. Recirculated room air can be filtered as it passes through the return air filter at the base of the unit. RADIANT FLOOR AND CEILING SYSTEMS Radiant heating systems transfer heat from hot water tubing or electric cables embedded in the floor or ceiling to a medium that will distribute heat to the specified space. Hydronic radiant heating is expensive because of the large amount of pipes and valves involved. These systems are more popular in residential projects than in commercial projects. Radiant floors induce convective air currents in the room because of the natural tendency of heated air to rise. Finish floors should not be made of a thermal insulating material; ceramic tile and wood flooring are suitable. Contributors: William R. Arnquist, AIA, Donna Vaughan & Associates, Inc., Dallas, Texas. Larry O. Degelman, PE, Texas A&M University, College Station, Texas. Walter T. Grondzik, PE, Florida A&M University, Tallahassee, Florida INTE R I O R CO N ST RU CT I O N 249 RADIATORS The classic rib-type cast-iron radiator was originally developed for use in steam systems and later adapted to hydronic hot water systems. Each unit is connected to a water supply and return branch and is normally equipped with an air vent. Hot water passes through the unit and heats the cast-iron ribs, which then heat the room by a combination of radiation and convection. The thermal mass of the radiator itself, plus the contained water, provide a thermal lag that acts to smooth out rapid temperature variations. The size and unsightliness of the classic ribbed radiator and the hazard of an exposed high heat source were two of the factors that led to the development of flat steel radiators. The ribs of these units are flat steel rectangular panels, arranged either vertically or horizontally. These units have a smaller thermal mass than cast-iron radiators. Some radiators are also available made from slender tubes, rather than flat panels. Finishes are typically chrome or painted. Towel warmer radiators range from about 26 to 61 in. (660 to 1,599 mm) in height, and are available 16, 20, 24, 30, and 36 in. (406, 508, 610, 762, and 914 mm) wide. Most electric types are available either hard wired or in plug-in models. Hydronic models are typically closed loop, although stainless steel models may also be used with open (domestic) systems. ELECTRIC HEATING SYSTEMS Electric heating systems for commercial use most commonly produce heat at the point of use. These systems, sometimes referred to as space heating systems, have a number of advantages. Installation costs are low because there is no need for a boiler or furnace, and expensive piping or ductwork is not required. Electric heat is also clean and quiet. However, electric heat is expensive in most parts of the United States, and a separate cooling system is required. Electricity used in these heating systems may come from hydroelectric or coal-fired power plants or, less commonly, from solar or wind sources. Electric energy is ideally suited for local space heating because it is simple to distribute and control. Electric heating systems are widely used in residences, schools, and commercial and industrial facilities. Heating units are placed in individual rooms or spaces and may be combined into zones with automatic temperature controls. Electric in-space heating systems may utilize natural convection, radiant, or forced-air units. • Natural convection units must be installed so that airflow across the resistor will not be impeded. • Radiant heaters are designed primarily to heat objects rather than space. Current flowing through a high-resistance wire heats up the element or surface of the unit. Heat is transferred from the unit to surfaces or occupants primarily by radiation. For an effective system, it is important to locate radiant heating units carefully in relation to the objects being heated. • Forced-air units combine convection heating with fan-powered air circulation. Such units are available in a wide range of capacities to suit a variety of heating loads and occupancy types. Unit ventilators are commonly used on an outside wall, where they have access to outdoor air intake and can prevent cold air downdrafts from window areas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 250 I N T E R IO R CO NST RU CTION Page 250 BUILDING SERVICES NATURAL CONVECTION UNITS 7.575 RADIANT HEATING UNITS 7.576 FORCED-AIR UNITS 7.577 HVAC SYSTEMS The two major considerations in the design of a commercial heating, ventilating, and air conditioning (HVAC) system are the source of energy (fuel) to be used and the method of distribution within the building. Heat can be distributed in a building by air, water (hydronic systems), or electricity. Energy efficiency is a major concern with HVAC systems, and new buildings and those undergoing major renovations are moving away from large ducted systems isolated within the building interior and toward natural ventilation and other alternatives. HEATING DISTRIBUTION SYSTEMS 7.578 SYSTEM ADVANTAGES DISADVANTAGES Air Can also perform other functions, such as ventilation, cooling, humidity control, and filtering. Prevents stratification and uneven temperatures by mixing air. Very quick response to changes in temperature. No equipment required in rooms being heated. Very bulky ducts require careful planning and space allocation. Can be noisy if not designed properly. Very difficult to use in renovations. Zones are not easy to create. Cold floors result if air outlets are high in the room. Hydronic Compact pipes are easily hidden within walls and floor. Can be combined with domestic hot water system. Good for radiant floor heating. For the most part, can only heat, not cool (exceptions: fan-coil units and valance units). No ventilation. No humidity control. No air filtering. Leaks can be a problem. Slightly bulky equipment in spaces being heated (baseboard and cabinet convectors). Radiant floors are slow to respond to temperature changes. Electricity Most compact. Quick response to temperature changes. Very easily zoned. Very expensive to operate (except heat pump). Wasteful. Cannot cool (except heat pump). Source: Norbert Lechner, Heating, Cooling, Lighting: Design Methods for Architects, 2nd ed., John Wiley & Sons, New York, 2001. Contributors: William R. Arnquist, AIA, Donna Vaughan & Associates, Inc., Dallas, Texas. Larry O. Degelman, PE, Texas A&M University, College Station, Texas. Walter T. Grondzik, PE, Florida A&M University, Tallahassee, Florida. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 251 BUILDING SERVICES AIR SYSTEMS There are dozens of different all-air comfort conditioning systems, each addressing the complex requirements of larger commercial buildings. In large buildings, there is often a simultaneous demand for heating, cooling, and ventilation. Rooms on the sunny side of a building need cooling, rooms on the shaded side need heating, and rooms in the building core require ventilation. Air circulates through ducts with the aid of a blower. INTE R I O R CO N ST RU CT I O N 251 AIR SYSTEM 7.580 Of the many year-round all-air systems in use, the most common are: • • • • • Single zone Multizone Single duct or terminal reheat Single-duct variable air volume Dual duct Because of their large size, air ducts require the most forethought in design and planning, while electrical heat requires the least. An air heating system requires 1 to 5% of the building’s volume for ducts and air-handling equipment. Underfloor air distribution systems are being used increasingly in commercial office spaces with raised access floors. COMMON DUCT SYSTEM LAYOUTS 7.579 VARIABLE AIR VOLUME AIR DISTRIBUTION 7.581 UNDERFLOOR AIR DISTRIBUTION SYSTEMS Underfloor air distribution (UFAD) systems used with raised access flooring are becoming the preferred way to distribute conditioned air in many buildings. They offer improved thermal comfort, more efficient ventilation, and better indoor air quality. The use of raised access flooring for air distribution as well as cabling improves flexibility and reconfiguring of spaces. With smaller ceiling plenums and floor plenums 8 in. (18 mm) or even lower, floor-to-ceiling heights are increased. In addition, UFAD systems are being shown to promote energy savings, and occupant satisfaction appears to improve with better user control over the interior environment. UFAD systems use the open space between the structural concrete floor slab and a raised access flooring system to circulate conditioned air to supply outlets. Typically, conditioned air from an airhandling unit is ducted to the underfloor plenum, and then flows openly to the supply outlets. The supply outlets are usually at floor level, but can also be installed at desktop level or in partitions. Air returns are usually at ceiling level, where return air can be carried in an unducted plenum. Contributor: Jeff Haberl, PE, Texas A&M University, College Station, Texas. William R. Arnquist, AIA, Donna Vaughan & Associates, Inc., Dallas, Texas. Larry O. Degelman, PE, Texas A&M University, College Station, Texas. Walter T. Grondzik, PE, Florida A&M University, Tallahassee, Florida. The central air handler can deliver air in several ways: • Through a pressurized underfloor plenum and into the occupied space through passive grilles or diffusers • Through an unpressurized underfloor plenum and into the space with fan-driven supply outlets working in conjunction with the central air handler • Through ducts in the underfloor plenum to supply outlets; this method is less energy and cost efficient In humid climates, it is necessary to dehumidify outside air for use as supply air to avoid condensation on cool structural slab surfaces. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 252 252 I N T E R IO R CO NST RU CTION BUILDING SERVICES A noticeable amount of air movement across the body when there is perspiration on the skin is experienced as a pleasant, cooling breeze. When surrounding surfaces and room air temperatures are 3°F or more below the normal room temperature, that same air movement can be experienced as a chilly draft. When the moving airstream is relatively cooler than the room air temperature, its velocity should be less than the speed of the other air in the room to avoid the sensation of a draft. Air motion is especially helpful for cooling by evaporation in hot, humid weather. UNDERFLOOR AIR DISTRIBUTION SYSTEMS 7.582 MECHANICAL VENTILATION Mechanical ventilation uses mechanical equipment to bring fresh air into a building and exhaust stale air and contaminants. Fans, either as stand-alone equipment or integrated into more complex systems, are used for supplying, circulating, and exhausting air. Unit ventilator fans on the outside wall of each room circulate room air and replace a fraction of it with outdoor air. Window or throughwall air conditioning units can also be run as fans. A central heating and cooling system with coils of hot or chilled water tempers the air in room ventilation units. Fixed location fans can provide a reliable, positive airflow to an interior space. Any time that air is exhausted from a building, makeup air must be supplied. This can be done in a limited manner by infiltration through the building envelope. Opening windows and doors can also provide a supply of fresh air. When mechanical equipment exhausts a large volume of air, makeup air is traduced through vents in the building envelope and directed to the equipment through ducts. ROOM FANS Fans can effectively cool small buildings. A person perceives a decrease of 1°F per 15 ft per minute increase in the speed of air past the body. The air motion produced varies with the fan’s height above the floor; the number of fans in the space; and the fan’s power, speed, and blade size. A slow-turning, ceiling-mounted paddle fan can extend a comfort range of 72 to 78°F up to about 82°F. Ceiling fans range from 29 to 72 in. (737 to 1,829 mm) in diameter. Spaces over 400 sq ft (37 sq m) may be best served by more than one fan. CEILING FAN SIZING 7.583 ROOM SIZE, SQ FT (SQ M) Up to 75 (7) Source: © Center for the Built Environment, University of California, Berkeley. DIFFUSERS, REGISTERS, AND GRILLES The air supply and return devices are often the only element of an HVAC system seen by building occupants. They have a direct impact on thermal and acoustical comfort, as well as on indoor air quality. Selection and specification of these devices are important parts of the design process. Three types of devices are used to supply and return air: • Diffusers are generally intended for ceiling-mounted supply air applications and are designed to provide good mixing of supply air with room air. • Registers are used for supply or return air applications and may be appropriate for ceiling, side wall, or floor installations. • Grilles are less sophisticated devices primarily intended for return air applications. Diffusers and registers are selected to deliver a specified airflow with appropriate throw (in terms of both distance and direction) and acceptable noise generation. Diffusers, manufactured of steel or aluminum, are available in a wide range of shapes, sizes, surface appearances, finishes, and installation detailing. Registers come in a more restricted range of shapes and sizes. Grilles are generally square or rectangular in shape. VENTILATION Ventilation is critical to human health. Fresh air supplies building occupants with oxygen and removes carbon dioxide. It also aids in the removal of contaminants from the interior environment and can help to maintain thermal comfort. Air motion may be caused by natural convection, may be mechanically forced, or may be a result of the body movements of a space’s occupants. NATURAL VENTILATION Natural ventilation occurs without the use of fans and other mechanical equipment. Convection will cause warm air to rise and cooler air to descend. As long as there are openings in a building’s envelope, differences in air pressure will bring in fresh air from outside and allow indoor air to escape. A well-insulated building with operable windows can aid in balancing the needs for fresh air, energy conservation, and thermal comfort. The natural convection of air over human bodies dissipates body heat without additional air movement. When temperatures rise, air movement must be increased to maintain thermal comfort. Insufficient air movement is perceived as stuffiness as air stratifies, with cool air near the floor and warmer air near the ceiling. FAN DIAMETER 29 to 36 (737 to 914 mm) 75 to 144 (7 to 13) 36 to 42 (914 to 1,067 mm) 144 to 225 (13 to 21) 44 to 48 (1,118 to 1,219 mm) 225 to 400 (21 to 37) 48 to 52 (1,219 to 1,321 mm) Over 400 (37) 54 to 72 (1,372 to 1,829 mm) 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 253 BUILDING SERVICES FAN HEIGHT 7.584 EXHAUST AIR SYSTEMS Exhaust fans remove odorous or overly humid air from bathrooms, kitchens, and process areas. They create negatively pressurized space that helps control the spread of odors. Exhaust fans may be very noisy. Energy-efficient models are available. In addition to ceiling mounts, exhaust fans come in models for mounting through the wall without ducting, with a concealed intake behind a central panel that can be decorated to match the room. Other models move air from one room to another through the intervening wall via grilles on both sides. LOCALIZED EXHAUST SYSTEMS Industrial process areas, laboratories, and critical medical care areas may require one or more fans and ductwork to the outside. Kitchens, toilet rooms, smoking rooms, and chemical storage rooms also should be directly exhausted to the outside. Photocopiers and other equipment may need localized exhaust ventilation. Healthcare and laboratory buildings often have “clean” and “dirty” zones. High air pressure in clean areas and lower air pressure in dirty areas help contain contaminants. Buildings with many exhausts have greater heating and cooling loads. In open offices with few walls, a designer can erect a barrier around contamination-producing copying machines and provide mechanical ventilation to task-ventilate the area immediately. BATHROOM EXHAUST FANS A bathroom fan should be located in the ceiling over the tub and shower, or high on the exterior wall opposite the door. It should discharge directly to the outside, at a point at least 3 ft (0.9 m) from any opening that allows outside air to enter the building. Residential bathroom fans are often combined with a lighting fixture, a fan-forced heater, or a radiant heat lamp. They should be UL listed and connected to branch circuits protected by ground fault BATHROOM VENTILATION 7.586 Source: Corky Binggeli, Building Systems for Interior Designers, 2nd ed., John Wiley & Sons, Hoboken, NJ, 2010. CEILING FANS 7.585 ENERGY STAR VENTILATION FAN 7.587 Source: Courtesy of RenewAire LLC. Contributors: Alfred Greenberg, PE, CEM, Murray Hill, New Jersey. American Gas Association, Washington, DC. National Kitchen and Bath Association, Hackettstown, New Jersey. INTE R I O R CO N ST RU CT I O N 253 circuit interrupters (GFCIs). Models are available with a high-efficiency centrifugal blower that provides virtually silent performance, and an illuminated switch that indicates when the fan is on. Some models are available that activate automatically to remove excess humidity, and some are designed to be easy to retrofit. PUBLIC TOILET ROOM VENTILATION Public toilet room plumbing facilities must be coordinated with the ventilation system to keep odors away from other building spaces while providing fresh air. The toilet room should be downstream in the airflow from other spaces. The air from toilet rooms should be exhausted outdoors, not vented into other spaces. By keeping slightly lower air pressure in the toilet rooms than in adjacent spaces, air flows into, rather than out of, the toilet room, thereby containing odors. Exhaust vents should be close to and above toilets. RESIDENTIAL KITCHEN VENTILATION HOODS Residential kitchen hoods work best when located directly over a range, catching the hot air as it rises. Fans that pull from several inches above the burner surface at the back of the stove and downdraft fans, including those on indoor grills, require significantly more airflow to be effective. In general, wall-mounted hoods are more effective than freestanding island hoods because there are fewer air currents to blow fumes away from the hoods. Range hoods vent through filters back into the room (self-venting) or through ducts and filters to the outdoors. Accessories such as fans, filters, and lights vary greatly in design configuration. It is best to install a fan that is no larger than needed. Some ranges and cooktops are equipped with downdraft venting, which may eliminate the need for an overhead range hood. Fans typically vent from 50 to 350 CFM (1.4 to 9.9 cu m/min) of air for standard residential cooktop use. TYPICAL KITCHEN HOOD INSTALLATION 7.588 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 254 I N T E R IO R CO NST RU CTION RANGE HOOD 7.589 Page 254 BUILDING SERVICES greater resistance to physical abuse, air erosion, high humidity, and deterioration from weather, ultraviolet (UV) light, and chemical exposure. COATING SELECTION The primary consideration in selecting products for both concealed and exposed applications is anticipating which exposure conditions will prevail during the life of the structure. CONCEALED APPLICATIONS Applications whose removal is unlikely during the life of the building, or in locations not requiring access for servicing of building environmental systems, appreciably reduce the risk of abrading or damaging the sprayed fire-resistive material. EXPOSED APPLICATIONS COMMERCIAL KITCHEN EXHAUST HOODS Commercial kitchen hoods collect grease, moisture, and heat at ranges and steam tables. Outside air may be introduced at or near the exhaust hood with minimal conditioning and then quickly exhausted; this saves heating and cooling energy. Exhaust hoods remove air, water vapor, grease, and food odors from the kitchen area, and air and water vapor from dishwashing areas. Ovens and steam-jacketed kettles only require hoods that remove air, heat, and water vapor; however, if large amounts of grease from a broiler, charbroiler, fryer, or grill are present, the hood system must extract this pollutant before the air is drawn outside by fans. This is done with grease “cartridges” or with stainless steel extractors, both of which violently blow the exhausted air around. The grease particles are collected in a trough for easy removal, or are run out a drain. TYPICAL EXHAUST HOOD REQUIREMENTS 7.590 Exposed applications present considerations that differ from those for concealed applications. For interior applications, select products that have not only the desired finished appearance but also the appropriate physical properties needed to resist deterioration from physical abuse, high humidity, air erosion, and corrosive atmospheres. A sealer or a topcoat may be recommended or required by manufacturers to protect exposed products. ENVIRONMENTAL CONSIDERATIONS Many of the raw materials used in making sprayed fire-resistive materials are obtained by mining, often from open pit mines. Mines, especially open pit mines, and mining operations are environmentally costly. They cause erosion; pollute water, air, and soils; and negatively alter and destroy ecosystems over large areas. Mining operations and transportation of mined raw materials require large amounts of energy. Wastes generated by mining, such as quantities of excavated soils and rocks, tailings, and toxic leachate, are difficult to dispose of. Tailing ponds, toxic leachate, and mine runoff may need long-term containment and monitoring, and are potential causes of pollution disasters. Indoor air quality issues related to sprayed fire-resistive materials include particulate inhalation, particulate eye and dermal irritation, volatile organic compound (VOC) emissions and absorption, and contamination by biological agents. Sensitive environments may have stringent requirements for the control of particulate matter in indoor air, VOC emissions, and potential pathogens. The removal and replacement of sprayed fire-resistive materials can be a significant source of indoor air pollution. FIRE ALARM AND DETECTION SYSTEMS SMOKE AND FIRE DETECTORS A fire progresses through four stages: incipient, smoldering, flame, and heat. Different types of fire and smoke detectors are designed to indicate problems at each stage. medium- to high-velocity airflow, and in closed areas with little airflow. In addition, they can be shielded against dirty, corrosive, humid, very hot, and very cold conditions. • Scattered-light photoelectric smoke detectors (Tyndall effect detectors): A pulsed light-emitting diode (LED) light beam is reflected from smoke particles and strikes the alarm cell. This type of detector is used in commercial and high-quality residential applications. They have a low sensitivity to normal dust and dirt accumulation or lamp aging, and require less maintenance than other types. • Laser beam photoelectric smoke detectors: This very high sensitivity laser diode source gives early warning. Laser beam photoelectric smoke detectors react to light scattered by particles; they can differentiate between smoke and dust particles. They are used in clean environments. • Air-sampling detection systems: These systems draw air through holes in pipes laid parallel to the ceiling plane over the protected area. Air passes a sensitive optical device, often a solid-state laser. Flame stage detectors include: • Ultraviolet (UV) radiation detectors: These UV long-range, very sensitive detectors react in milliseconds and respond to most types of fires. They detect reflected UV radiation from walls and ceilings, but can be blinded by thick black smoke. They are used in highly flammable or explosive storage and work areas and to detect fires of organic materials. Their use requires provisions for rapid fire suppression and building evacuation. • Infrared (IR) radiation detectors: IR radiation detectors detect rapid flaming combustion and carbon dioxide production; they react in seconds. They are used in enclosed spaces such as sealed storage vaults. IR radiation detectors have less range and lower sensitivity than UV detectors. • Combined UV/IR radiation detectors: This hybrid type reduces the number of false alarms. They are used in aircraft hangars, fueling stations, and flammable storage areas. • Spot units: These are mounted in the center of a protected area to respond to hot air convection from a fire. • Linear units: These respond to hot air convection from a fire along the entire length of the unit. Linear units detect overheating of a surface without the presence of fire. They are used in cable trays and bundles and for large, long equipment. The effectiveness of smoke detectors is measured by the effect of smoke on reducing visibility, or obscuration. Photoelectric detectors have the highest obscuration levels, followed by ionization detectors. Residential smoke detector use is covered by state and local codes, which may require hard-wired, rather than battery-operated, detectors. The NFPA recommends smoke detectors in each bedroom, outside each sleeping area, and on every level of a residence. Check the local codes for specific requirements. Incipient stage detectors include: FIRE PROTECTION SYSTEMS APPLIED FIRE PROTECTION Several methods, both active (sprinklers) and passive, are possible for protecting building structures from fire. Designing for fire protection might include dividing a building into isolated modules with a limited number of penetrations for fire-rated doorways, electrical conduits, and ducts. Modules could be protected with sprayed fire-resistive materials, sprinklers, or both, depending on use, occupancy, potential exposure to abusive environments and individuals, and requirements of authorities having jurisdiction. SPRAY-APPLIED FIRE-RESISTIVE COATINGS Sprayed fire-resistive materials protect structural steel in both concealed and exposed applications. They include low-density cementitious and sprayed-fiber products, used predominantly for concealed locations, and a variety of medium- and high-density products, used for exposed locations that require a more finished appearance and Contributors: Alfred Greenberg, PE, CEM, Murray Hill, New Jersey. American Gas Association, Washington, DC. National Kitchen and Bath Association, Hackettstown, New Jersey. Syska and Hennessy, Consulting Engineers, New York, New York. Warren D. Bonisch, PE, Schirmer Engineering, Richardson, Texas. • Ionization smoke detectors: These provide early warning with instantaneous response once particles are detected. They are used indoors to detect large particles in areas with low airflow. Ionization smoke detectors are not used where warm air collects, or where particles are usually present. They require periodic cleaning and recalibration. • Gas-sensing fire detectors: These are an early-warning type often used with particulate detectors to detect combustion gases. • Wilson cloud chamber detectors: This is a very sensitive earlywarning type used in museums, data-processing spaces, libraries, cleanrooms, and facility control rooms. Wilson cloudchamber detectors detect microscopic particles with few false alarms. They require the expense of installing piping. SMOKE DETECTORS 7.591 Smoldering stage detectors include: • Projected-beam photoelectric smoke detectors: A beam transmitter and beam receiver on opposite sides of a space detect particles in smoke; this requires unobstructed view. Projected beam smoke detectors have a slower response than incipient stage detectors. They are used in high-ceiling areas such as atriums, churches, malls, and auditoriums. They can be used with Source: Corky Binggeli, Building Systems for Interior Designers, 2nd ed., John Wiley & Sons, Hoboken, NJ, 2010. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 255 BUILDING SERVICES PROJECTED-BEAM SMOKE DETECTORS 7.592 fire doors and shutters, releasing locked doors, capturing elevators, and transmitting voice messages. The simplest fire alarm system is a self-contained, UL-approved residential smoke detector. It senses products of combustion, sounds an alarm, and signals when the battery needs replacement. Most municipalities require the use of smoke detectors in houses, apartments, and motel or hotel rooms. Check local codes for requirements. SMOKE ALARM PLACEMENT 7.593 More complex systems are needed in buildings where public safety is an issue, such as schools, hospitals, office buildings, and other commercial establishments or institutions. Although there are still applications for small hard-wired and relay-operated alarm signaling systems, the trend is to use microprocessor-based digital multiplex systems that not only signal the presence of a fire but also initiate other measures, including conditioning fans and dampers for smoke control, closing fire doors and shutters, releasing locked doors, capturing elevators, and transmitting voice messages. Voice communication is required in high-rise buildings of specific group occupancies. It is also recommended for large low-rise buildings to enhance life safety. AUDIBLE ALARMS Audible alarms must have an intensity and frequency capable of attracting the attention of those with partial hearing loss. Such alarms should produce a sound that exceeds either the prevailing sound level in the space by at least 15 dBA or the maximum sound level with duration of 60 seconds by 5 dBA, whichever is louder. Sound levels should not exceed 120 dBA. VISUAL ALARMS Visual alarms should be placed 80 in. (2,032 mm) above the highest floor level within the space, or 6 in. (152 mm) below the ceiling, whichever is lower. In any space required to have a visual alarm, generally all areas must be within 50 ft (15.2 m) of the signal (measured horizontally). In large spaces, such as auditoriums, exceeding 100 ft (30.5 m) across, with no obstructions over 6 ft (1.8 m) high, devices may be placed around the perimeter, spaced a maximum of 100 ft (30.5 m) apart, in lieu of suspending devices from the ceiling. INTE R I O R CO N ST RU CT I O N 255 ATRIUM SMOKE MANAGEMENT An atrium can be considered a large space of two or more stories. Other large open spaces include enclosed shopping malls, arcades, sports arenas, exhibition halls, and airplane hangars. The term atrium is used in a generic sense to mean any of these large spaces. Atrium smoke management is regulated by building codes. Currently, most codes prescribe atrium smoke protection that is based on the zone fire model concept. Consult with a fire and smoke consultant and mechanical engineer to review project conditions relating to atrium smoke management. • Smoke control is reserved for systems that provide smoke protection by use of pressurization, such as a pressurized stairwell. • Smoke management refers to systems that use any technique, including compartmentalization, pressurization, airflow, and buoyancy of hot smoke. Using this terminology, atrium exhaust systems are smoke management systems because they rely on the buoyancy of hot smoke. For smoke management purposes, smoke consists of the airborne products of combustion plus the air that is mixed with them. The airborne products are combustion gases and solid and liquid particulates. The smoke being generated, exhausted, or vented is actually air mixed with relatively small quantities of particulates and combustion gases. Because the concentrations of these other quantities are relatively small, engineering design analysis for these smoke management systems considers the specific heat, gas constant, and other properties of smoke to be the same as those of air. STRATIFIED SMOKE IN ATRIUM 7.596 MANUAL PULL STATION 7.594 PLUGHOLING 7.597 HORN/SPEAKER/VISUAL SIGNAL 7.595 FIRE ALARM SYSTEMS Fire alarm systems protect the environment they serve by sensing products of combustion (smoke detectors) through the utilization of manual alarm-initiating devices (pull stations), by sprinkler system activation (water flow switches), or by detecting sudden increases in temperature (heat detectors). Fire alarm systems can vary in size and complexity. They range in size from a single, self-contained, residential smoke detector to a microprocessor-based, digital multiplex system serving a complete facility. A fire alarm system not only signals the presence of a fire but also initiates other measures, including control of the fan and damper systems for smoke containment and evacuation, closing Contributors: Richard F. Humenn, PE, Joseph R. Loring and Associates, Consulting Engineers, New York, New York. JRS Architect, Mineola, New York Warren D. Bonisch, PE, Schirmer Engineering, Richardson, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 256 I N T E R IO R CO NST RU CTION STAIR PRESSURIZATION Stair pressurization is regulated by the building code. Generally, it is limited to those enclosed exit stairs that serve normally occupied floors (a) 75 ft (22.9 m) or higher above and (b) 30 ft (9.1 m) or lower below the level of fire department access to a building. Fire department access is generally defined as the elevation of the fire lane serving the building. The purpose of stair pressurization is to create a protected space for firefighter operations. Essentially, air is added to the stair enclosure via supply air fans, which creates a positive pressure within the stair relative to the adjacent spaces served by that stair. Hence, when activated, the air flows from the stair toward the adjacent spaces. This airflow reduces the probability that smoke will enter the exit stair. The design parameters related to stair pressurization are many and complex. (Refer to Principles of Smoke Management by Klote and Milke.) Several, however, impact the project interior design. Longer (i.e., taller) stair shafts may require the injection of supply air at multiple levels of the stair enclosure. This will necessitate an adjacent air supply shaft. This supply air shaft must be dedicated to the stair pressurization system serving that stair, as it cannot be shared or used to supply other mechanical needs. One type of stair pressurization system requires vestibules located between the stair enclosure and adjacent spaces served by that stair. The vestibule is typically a one-hour rated enclosure of specific height and width, and is provided with either mechanical supply/exhaust air or is open directly to the exterior. The theory is that smoke from the adjacent space would enter the vestibule and be vented mechanically or exhausted naturally through the opening to the exterior, thereby reducing the probability of smoke entering the stair enclosure. POSITIVE PRESSURIZATION 7.598 Page 256 BUILDING SERVICES ESCALATOR AND NONREQUIRED STAIRWAY OPENINGS A common building feature is to connect one or more levels with either an escalator and/or a nonrequired stairway. The floor opening created thereby is permitted to be open, provided the area of the floor opening does not exceed twice the horizontal projected area of the escalator or stairway and the opening is protected by a draft curtain and closely spaced sprinklers in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems. The number of stories that can be open is limited by the occupancy of the connected spaces. NFPA 13 requires an 18 in. (457 mm) noncombustible draft curtain with sprinklers 6 to 12 in. (152 to 305 mm) away from the draft curtain, spaced 6 ft (1.8 m) on center around the opening. The theory is that the heat and hot gases from a fire would reach the draft curtain and be delayed, thereby activating the fire sprinklers. Without the draft curtain, the heat and hot gases could pass between two normally spaced sprinklers about 15 to 20 ft (4.6 to 6 m) apart, and rise up through the floor opening unchecked. FIRE SUPPRESSION SYSTEMS Three things are necessary for a fire to be maintained: fuel, oxygen, and a temperature high enough to start ignition or maintain combustion. All fire-extinguishing methods remove one or all of these elements, causing the fire to be extinguished. Fires are classified as Class A, B, C, or D: • Class A fires occur in solid, combustible materials, such as wood and paper. • Class B fires occur in combustible liquids, such as oil and gasoline. • Class C fires are electrical in nature, such as a short circuit that causes a spark capable of igniting other substances. • Class D fires occur in metals with their own fuel supply. Building occupancy and other specific areas within a building are classified as light, ordinary, or extra hazard, according to the potential for fire. Light hazard occurs in office buildings, schools, and public buildings. Ordinary hazard is found in warehouses and stores with large amounts of combustible material. Extra hazard occurs where there is considerable potential for easily started, large fires. These classifications are more fully explained in the applicable NFPA standards. FIRE SUPPRESSION SYSTEM TYPES Three general types of systems are used for suppression of fires: water based, chemical based (either liquid or powder), and gas based. • Water-based systems use either water mixed with chemicals that add fire-extinguishing characteristics or undiluted water to cool the fire below ignition temperature or deprive it of oxygen. • Chemical-based systems interfere with the combustion process and deprive the fire of oxygen. • Gas-based systems interfere with the combustion process and deprive the fire of oxygen. SPRINKLER SYSTEMS A sprinkler system uses water distributed through a network of valves, piping, and nozzles whose primary purpose is to set off an alarm and mitigate the effects of a fire, not necessarily to extinguish it. When a fire condition is present, the heat of the fire melts the element of a closed sprinkler head, allowing water to discharge automatically onto the fire. ESCALATOR FIRE SAFETY 7.599 ELEVATOR LOBBY ENCLOSURES AND PRESSURIZATION The requirement for elevator lobby enclosures resides in the building code. Enclosures are generally required for elevators in high-rise buildings, even if the building is protected by fire sprinklers. (The exceptions to the requirement for lobbies include low-rise buildings, open parking garages, street floor lobbies, and elevators that are not located in an elevator shaft.) The requirement for enclosed elevator lobbies has recently been expanded to include fire department access elevators and occupant evacuation elevators. Elevator lobbies are generally enclosed with 1 hour fire-rated construction and 45 minute opening protectives. The size of the elevator lobby’s enclosure will be dictated by accessibility, fire department access elevator, and occupant evacuation elevator requirements. Contributors: John H. Klote, John H. Klote, Inc., McLean, Virginia. Warren D. Bonisch, PE, Schirmer Engineering, Richardson, Texas. Source: Based on drawing by Francis D. K. Ching in Building Codes Illustrated, 2nd ed., John Wiley & Sons, Hoboken, NJ, 2007. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 257 BUILDING SERVICES TYPICAL SPRINKLER CONNECTION 7.600 INTE R I O R CO N ST RU CT I O N 257 SPRINKLER HEAD SELECTION CHART 7.602 SPRINKLER HEAD TYPE STANDARD COVERAGE HIGH EXTENDED PRESSUREa COVERAGE RESIDENTIAL DRY FOAM WATER INSTITUTIONAL Upright X X X — X X — Standard response X — — — — — — Quick response X — — — — — — Pendant X X X X X X X Recessed pendant X X X X — — — Concealed pendant X — — X — — — Flush pendant X — — — — — — Horizontal side wall X X X X X — X Recessed horizontal side wall X X — X X — — Vertical side wall X — — — — — — Pendant with deep escutcheons — — — — X — — SPRINKLER HEAD TYPES 7.603 Sprinkler system types include the following: • Wet pipe : This automatic system uses piping filled with water under pressure and closed heads. When a fire condition exists, the heat melts (fuses) a temperature-sensitive element in the head, causing the head to open and water to flow. • Dry pipe : This automatic system uses piping filled with air under pressure and closed heads. The operating valve assembly is called a dry pipe valve. An air compressor is required to make up air lost through leakage. Both water and compressed air are supplied only to the dry pipe valve. When a head fuses due to a fire condition, it lowers the air pressure, opens the valve, and permits water to enter the piping; the water then flows only from the open heads. • Preaction : This automatic system uses closed heads and piping filled with air under atmospheric pressure. Water is supplied to the operating valve assembly, called a preaction valve. An ancillary smoke or fire detection system initiates a signal upon detection of heat, fire, or smoke. The signal causes the preaction valve SPRINKLER SYSTEM TYPES 7.601 NOTE 7.601 a. 300 psi (210,900 kg/sq m). Contributors: Michael Frankel, CIPE, Utility Systems Consultants, Somerset, New Jersey. Jeffrey Meese, AIA, Cambridge, Massachusetts. to open, allowing water to enter the piping system. Water will not flow out of the heads unless they fuse due to a fire condition. • Deluge : Used to protect high-hazard areas and specific equipment, this automatic system uses piping filled with air under atmospheric pressure and open heads. An ancillary smoke or fire detection system is required to initiate a signal upon detection of heat, fire, or smoke at the hazard being protected. • Antifreeze : A wet pipe automatic system is filled with an antifreeze solution instead of water to protect areas subject to freezing but too small for a dry pipe system. Operations are similar to those of the standard wet pipe system. • Water mist : This automatic system uses high-pressure water flowing through nozzles designed to discharge very small droplets of water directly onto a fire. A water pump is required to produce the high system pressure. TYPICAL SPRINKLER HEAD SPRAY PATTERNS 7.604 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 258 I N T E R IO R CO NST RU CTION FIRE SUPPRESSION CODE REQUIREMENTS Fire detection and suppression refers to any fire alarm or fireextinguishing system that is designed and installed to detect, control, or extinguish a fire, or to alert the occupants or the fire department that a fire has occurred. For dwelling units, the system may be limited to smoke detectors. In commercial buildings, the system may include many elements, such as smoke and heat detectors, sprinklers, portable fire extinguishers, standpipes, smoke control systems, manual alarms, and smoke and heat vents. Page 258 BUILDING SERVICES TYPES OF FIRE EXTINGUISHER AGENTS OBSTRUCTION CONDITIONS 7.606 The agent within a fire extinguisher is usually one of the following: • Carbon dioxide : This colorless, odorless, electrically nonconductive inert gas is suitable for Class B and C fires. • Wet chemical: This is an aqueous solution of organic or inorganic salts. • Dry chemical : Powder of sodium bicarbonate, potassium bicarbonate, and other chemicals similar to baking soda. It is commonly used for Class A, B, and C fires, but results in a mess once discharged • Water : Common, inexpensive, sustainable agent, but limited to Class A fires. Water is used in nonfreezing locations. • Halon and halocarbon : Clean agent that leaves little to no residue. These agents can be listed for Class A, B, and C fires. Higher costs than some agents. Halon is banned in Europe and sent to the United States for reuse; new supplies cannot be produced. Alternative related materials are available. • Film forming : Aqueous film-forming foam (AFFF) or film foamforming fluoroprotein foam (FFFF). Film forming agents are limited to Class A and B fires and used in nonfreezing locations. The purpose of a fire suppression system is to extinguish or mitigate the effects of a fire. Selection of the extinguishing medium most appropriate for a project is based on availability, compatibility, cost, and code requirements. Although the design and layout of a sprinkler system is the responsibility of the mechanical engineer or fire protection contractor, the preferred location of the heads is often based on the designer’s reflected ceiling plan. LOCATING SPRINKLER HEADS For light-hazard occupancies such as offices, stores, and restaurants, one sprinkler head is required for each 225 sq ft (21 sq m) of floor area if the system is hydraulically designed. LOCATING FIRE EXTINGUISHERS If obstructions are present, such as beam enclosures, dropped ceilings, tall bookshelves, or high office system partitions, certain horizontal and vertical dimensions must be maintained. DEFINITIONS • Noncombustible : A material that meets the requirements of ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 °C. This means that the material will not ignite or burn when subjected to fire. Noncombustible also includes composite materials, such as gypsum wallboard, that are composed of a surfacing not more than 0.125 in. (3 mm) thick and that have a flame spread index not greater than 50, as long as the structural base is noncombustible. • Flame resistant : A material that restricts the spread of flame in accordance with NFPA 701, Standard Methods of Fire Tests for Flame Propagation of Textiles and Films. This test is commonly referred to as the Vertical Ignition Test. • Trim : Picture moldings, chair rails, baseboards, handrails, door and window frames, and similar decorative or protective materials used in fixed applications. • Combustible : A material that will ignite and burn, either as a flame or glow, and that undergoes this process in air at pressures and temperatures that might occur during a fire in a building SPRINKLER HEAD LOCATIONS 7.605 COMMERCIAL COOKING FIRE SUPPRESSION The need for fire suppression systems to protect commercial cooking appliances is found in the fire code. Commercial cooking appliances are those that heat or cook food which results in the production of grease vapors, steam, fumes, smoke, or odors that are required to be removed through a local exhaust ventilation system. Examples include deep fat fryers, griddles, broilers, kettles, ranges, and other equipment. A hood over such an appliance is an air intake device used to capture grease and similar contaminants before they enter a duct system. Due to the production of grease, smoke, and other products, the kitchen hood is required to be protected by an automatic fire suppression system. Portable fire extinguishers are required also, to serve as a secondary backup. FIRE EXTINGUISHERS Fire extinguishers are intended to be the first line of defense in the early stages of a fire, when the fire is just starting and therefore limited in size and intensity. The requirement for fire extinguishers comes from the fire code. CLASSIFICATION OF EXTINGUISHERS Fire extinguishers are labeled based on the type of fire they are designed to extinguish. It is difficult to anticipate each and every use of a building and its associated fire hazard. Therefore, it is best to specify multipurpose fire extinguishers. (Multipurpose fire extinguishers are those extinguishers with one or more classification as listed above.) FIRE EXTINGUISHER CLASSIFICATIONS 7.607 FIRE CLASSIFICATION Contributor: Warren D. Bonisch, PE, Schirmer Engineering, Richardson, Texas. FIRE HAZARD Class A General combustibles, such as paper, wood, and cloth Class B Flammable and combustible liquids, such as paints, oils, and solvents Class C Energized electrical equipment Class D Combustible metals, such as magnesium and titanium Class K Cooking appliances that can cause vegetable or animal oil fires Fire extinguishers need to be mounted off the floor by placing them within a cabinet or on a mounting bracket securely attached to a wall. An important goal is for the fire extinguisher to be readily visible in a normal path of travel. Locating it behind a door or around a corner, for instance, defeats the purpose of providing a fire extinguisher. A uniform spacing of fire extinguishers, especially from floor to floor and within common areas, increases the likelihood that the extinguisher will be found when needed. It also helps during inspections and maintenance. With greater concern for security, there are more locked doors. Make sure fire extinguishers are located on the secured side of a doorway so that travel back through a locked door is not required to get a fire extinguisher and return to the fire location. Fire extinguishers should be placed so that the top of the extinguisher is no more than 60 in. (1,524 mm) above the floor when the extinguisher weighs no more than 40 lb (18.1 kg), and no more than 42 in. (1,067 mm) above the floor when the extinguisher weighs more than 40 lb (18.1 kg). In no case can the extinguisher bottom be less than 4 in. (102 mm) above the floor. With the exception of the special hazards listed below, fire extinguishers are typically located based on travel distance and area of coverage. Travel distance to a fire extinguisher can vary based on the fire hazard, fire extinguisher size, and so on, but it should not exceed 75 ft (22.9 m) for a Class A rating. Lay the fire extinguisher locations out on a floor plan, with the radius of the circle not exceeding 75 ft (22.9 m). Make sure the circles overlap so that no floor area is greater than 75 ft (22.9 m) of travel to a fire extinguisher. The maximum area per fire extinguisher with a Class A rating is 11,250 sq ft (1,045 sq m). Class B fire extinguishers are limited to either 30 or 50 ft (9.1 or 15.2 m) of travel, based on the type of hazard. FIRE EXTINGUISHER MOUNTING HEIGHTS 7.608 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 259 BUILDING SERVICES FIRE EXTINGUISHER FLOOR PLAN 7.609 INTE R I O R CO N ST RU CT I O N 259 ELECTRICAL SYSTEMS SURFACE RACEWAY SYSTEMS 7.610 WIRING DEVICES ELECTRICAL BOXES A junction box is an enclosure for housing and protecting electrical wires or cables that are joined together when connecting or branching electrical circuits. Junction boxes may be round, square, or octagonal. Boxes are mounted to wood floor structures (nonadjustable) or cast-in-place concrete with leveling screws. Concrete boxes include cast-iron, stamped-steel, or nonmetallic materials. Metallic and nonmetallic boxes are available. Flush mounting in concrete requires a concrete-tight box and rigid conduit and tubing. In concrete masonry unit (CMU) construction, raceway tubing that is expressly designed to hold and protect electrical wires and cables is threaded through cavities in the blocks. Three common electrical box types include the following: • Octagonal boxes are commonly used for flush ceiling outlets. They may also be used as floor boxes for monument receptacles. • Flush floor boxes are mounted to a wood floor structure (nonadjustable) or cast-in-place concrete with leveling screws. Concrete boxes include cast-iron, stamped-steel, or nonmetallic materials. This is a heavy-duty box, in comparison to a standard octagonal floor box for monument receptacles. • Utility electrical boxes are available in metallic and nonmetallic versions. Knockout locations vary. Utility and exterior boxes are not gangable; switch and masonry boxes may be. Flush mounting in concrete requires a concrete-tight box and rigid conduit and tubing. In CMU construction, a raceway or tubing is threaded through the cavities. Contributors: Warren D. Bonisch, PE, Schirmer Engineering, Richardson, Texas. William G. Miner, AIA, Architect, Washington, DC. Charles B. Towles, PE, TEI Consulting Engineers, Washington, DC. Richard F. Humenn, PE, Joseph R. Loring & Associates, Inc., Consulting Engineers, New York, New York. Gary A. Hall, Hammel Green and Abrahamson, Minneapolis, Minnesota. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 260 I N T E R IO R CO NST RU CTION ELECTRICAL BOXES 7.611 Page 260 BUILDING SERVICES STANDARD MOUNTING HEIGHTS FOR ELECTRICAL DEVICES 7.612 RECEPTACLES AND SWITCHES 7.613 NOTES 7.613 a. The outlets and switches are those most commonly used. The number of gangs behind one wall plate depends on the type of devices used. b. Symbols used are ANSI standard Y32.2. c. Interchangeable (miniature) devices are available in various combinations using any of the following in one gang: switch, convenience outlet, radio outlet, pilot light, bell button. Combined gangs are available. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 261 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 261 GANG SIZE 7.614 GANG HEIGHT WIDTH 2 4-1/2 (115 mm) 4-9/16 (116 mm) 3 4-1/2 (115 mm) 6-3/8 (162 mm) 4 4-1/2 (115 mm) 8-3/16 (208 mm) 5 4-1/2 (115 mm) 10 (254 mm) 6 4-1/2 (115 mm) 11-13/16 (298 mm) SWITCH AND OUTLET LOCATIONS 7.615 DISTRIBUTION SYSTEMS POKE-THROUGH SYSTEMS Poke-through systems are used in conjunction with overhead branch distribution systems that run in accessible suspended ceiling cavities to outlets in full-height partitions. When services are required at floor locations without adjacent partitions or columns, as in open-plan offices, they must either be brought down from a wireway assembly (known as a power pole) or up through a floor penetration containing a fire-rated insert fitting and flush or abovefloor outlet assembly. To install a poke-through assembly, the floor slab must either be core drilled or contain preset sleeves arranged in a modular grid. Poke-through assemblies are used in conjunction with cellular deck and underfloor duct systems when the service location required does not fall directly above its associated system raceway. With one floor penetration, the single poke-through assembly can serve all the power, communications, and computer requirements of a workstation. Distribution wiring in the ceiling cavity can be run in raceways. The more cost effective method is to use armored cable (BX) for power and approved plenum-rated cable for communications and data when the ceiling cavity is used for return air. To minimize disturbance to the office space below when a pokethrough assembly must be relocated or added, a modular system of prewired junction boxes for each service can be provided, although it is more common to elect this option for power only. A different type of working system must be selected for a floor slab on grade, above a lobby or retail space, above mechanical equipment space, or above space exposed to the atmosphere. The low initial cost of a poke-through system makes it both viable and attractive for investor-owned buildings where tenants are responsible for future changes, and for corporate buildings with limited construction budgets. Poke-through systems are effective when office planning includes interconnecting workstation panels containing provisions (base raceways) to extend wiring above the floor, reducing the number of floor penetrations needed for services. Contributors: Charles B. Towles, PE, TEI Consulting Engineers, Washington, DC. Richard F. Humenn, PE, Joseph R. Loring & Associates, Inc., Consulting Engineers, New York, New York. Gary A. Hall, Hammel Green and Abrahamson, Minneapolis, Minnesota. Robert T. Faass, Consulting Engineer, Seabrook, Maryland. Richard J. Vitullo, AIA, Oak Leaf Studio, Crownsville, Maryland. POKE-THROUGH HARDWARE SYSTEM/ZONE JUNCTION BOX 7.616 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 262 I N T E R IO R CO NST RU CTION RAISED-ACCESS FLOOR SYSTEM A raised-access floor system provides maximum flexibility and lowest cost to relocate or add service. When used in conjunction with a modular system of power, communications and data wiring plugin receptacles, and cable connector sets, changes can be made without an electrician or wiring technician. Access flooring systems have the highest initial cost of distribution system types. Access floors can be provided with or without stringers, which are used to minimize the “creep” effect. For a custom installation without ramps or steps, the base floor is depressed. Access floors do not necessarily require an increase in floor-tofloor height, and if so, the height added is at a much lower per unit cost than for the rest of the building. When special attention is given to coordinating lighting with other elements in the suspended ceiling, or when lighting is provided below (as from the workstations), the cavity can be compressed to compensate for the raised floor. Page 262 BUILDING SERVICES RAISED-ACCESS FLOOR SYSTEM WITH MODULAR PLUG-IN DISTRIBUTION 7.617 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 263 BUILDING SERVICES FLAT-CABLE WIRING SYSTEM Flat cable originates at transition boxes located at various intervals along core corridor walls and columns that are individually served from distribution centers in utility closets. Boxes can also be cast in the floor or atop a poke-through insert. Cables are not permitted to pass under fixed partitions and must be carefully mapped out to minimize crossovers and clutter. FLAT-CABLE WIRING SYSTEM 7.618 To install a service fitting, an interface base assembly must first be secured directly to the concrete floor at the flat-cable location. The base assembly stabs into conductors of the flat cable and converts them to round wire. When the service fitting is attached, it is activated and ready for use. Careful consideration must be given to the application of this system based on limitations that may or may not be acceptable under different conditions. For example, it may be ideal for small areas or renovation of existing buildings where the poke-through or power pole systems are unacceptable or cannot be used. In new construction where poke-through has been chosen as the base building standard system, the flat-cable system is a viable solution in areas where poke-through outlets cannot be installed, such as slab on grade. Carpet tiles are required by most building codes as the floor covering to be used over flat-cable installations to facilitate access to the flat cable. Where frequent changes and additions are anticipated, the resulting wear and tear on expensive, glued-down carpet tile may be a disadvantage. Flat-cable systems are labor intensive to install. Actual installed initial costs and outlet relocation costs are comparable to cellular deck with trench header ducts. RESIDENTIAL ELECTRICAL WIRING The general requirements for residential electrical wiring systems include: 1. A minimum of one wall switch–controlled lighting outlet is required in every habitable room, hallway, stairway, attached garage, and outdoor entrance. An exception is in habitable rooms other than kitchens and bathrooms, where one or more receptacles controlled by a wall switch are permitted in lieu of lighting outlets. 2. In every kitchen, family room, dining room, den, breakfast room, living room, parlor, sunroom, bedroom, recreation room, and similar rooms, convenience outlets must be installed so TYPICAL RESIDENTIAL ELECTRICAL LAYOUT—SCHEMATIC DIAGRAM 7.619 NOTE 7.619 A wide variety of UPS systems are available for smaller applications, ranging from desktop models for single microcomputers to floor models that can supply several computers or other equipment. Contributors: Richard F. Humenn, PE, Joseph R. Loring & Associates, Inc., Consulting Engineers, New York, New York. Gary A. Hall, Hammel Green and Abrahamson, Minneapolis, Minnesota. Charles B. Towles, PE, TEI Consulting Engineers, Washington, DC. INTE R I O R CO N ST RU CT I O N 263 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 264 I N T E R IO R CO NST RU CTION that no point along the floor line is farther than 12 ft (3.7 m) measured horizontally from an outlet, including any wall space 2 ft (0.61 m) or more wide, and the wall space occupied by sliding panels in exterior walls. 3. A minimum of two #12 wire 20 A small-appliance circuits are required to serve small convenience outlets exclusively, including refrigeration equipment, in the kitchen, pantry, dining room, breakfast room, and family room. Both circuits must extend to the kitchen; the other rooms may be served by one or both of them. No other convenience outlets may be connected to these circuits, except a receptacle installed solely for an electric clock. In kitchen and dining areas, convenience outlets must be installed at each and every counter space wider than 12 in. (305 mm). 4. A minimum of one #12 wire 20-A circuit must be provided to supply the laundry receptacle(s), and it may have no other convenience outlets. 5. At least one convenience outlet must be installed in the bathroom near the basin and must be provided with ground fault circuit interrupter (GFCI) protection. 6. Code requires sufficient 15- and 20-A circuits to supply 3 W of power for every square foot of floor space, not including garage and open porch areas. Minimum code suggestion is one circuit per 600 sq ft (55.7 sq m), but one circuit per 500 sq ft (46.5 sq m) is desirable. 7. A minimum of one exterior convenience outlet is required (two are desirable) and must be provided with GFCI protection. 8. A minimum of one convenience outlet is required in the basement and garage, in addition to the one in the laundry. In attached garages, it must be provided with GFCI protection. 9. Many building codes require a hard-wired smoke detector in the hallway outside bedrooms or above the stairway leading to upper-floor bedrooms. 10. Disconnect switches are required for equipment. Page 264 BUILDING SERVICES FIRST-FLOOR AND BASEMENT PLANS OF ELECTRICAL EQUIPMENT AND DEVICES 7.620 LEGEND A. Mount convenience outlets at countertop locations 2 in. (51 mm) above backsplash. B. Mount convenience outlets 48 in. (1,219 mm) above finish floor (AFF). C. Range and oven outlet boxes should be wall mounted 36 in. (914 mm) AFF. Use flexible connections to units. D. Switch and outlet for exhaust fan. The switch should be cover mounted adjacent to the fan wall opening. A separate switch may be omitted if the fan is supplied with an integral switch. E. Dishwasher outlet is wall mounted behind unit, 6 in. (152 mm) AFF. F. Equipped with self-closing waterproof cover with gasket. G. Mount 42 in. (1,067 mm) AFF. NOTES 7.620 a. Wiring shown as exposed indicates absence of finished ceiling in basement level. All BX cable is run through framing members. Attachment below ceiling joists is not permitted. b. Connect to two incandescent porcelain lamp holders with pull chain. Mount two evenly spaced ceiling fixtures in crawl space. c. Connect to shutdown switch at top of stairs. d. Boiler wiring safety disconnect switch should have red wall plate, clearly marked “BOILER ON/OFF.” Contributor: Charles B. Towles, PE, TEI Consulting Engineers, Washington, DC. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 265 BUILDING SERVICES LIGHTING LOADS, CIRCUITS, AND RECEPTACLES FOR RESIDENTIAL ELECTRICAL EQUIPMENT 7.621 APPLIANCE TYPICAL CONNECTED, VA VOLTS WIRES CIRCUIT BREAKER OR FUSE, A OUTLETS ON CIRCUIT NEMA DEVICE AND CONFIGURATION KITCHEN Range 12,000 115/230 3 #6 60 1 14-60R Oven (built-in) 4,500 115/230 3 #10 30 1 14-30R Range top 6,000 115/230 3 #10 30 1 14-30R Dishwasher 1,200 115 2 #12 20 1 5-20R Garbage disposer 300 115 2 #12 20 1 5-20R Broiler 1,500 115 2 #12 20 1 or more 5-20R Refrigerator 300 115 2 #12 20 1 or more 5-20R Freezer 350 115 2 #12 20 1 or more 5-20R 5-20R LAUNDRY Washing machine 1,200 115 2 #12 20 1 or more Dryer 5,000 115/230 3 #10 30 1 14-30R Hand iron 1,650 115 2 #12 20 1 or more 5-20R LIVING AREAS Workshop 1,500 115 2 #12 20 1 or more 5-20R Portable heater 1,300 115 2 #12 20 1 5-20R Television 300 115 2 #12 20 1 or more 5-20R Fixed lighting 1,200 115 2 #12 20 1 or more 5-20R Air conditioner, 3/4 hp 1,200 115 2 #12 20 or 30 1 5-20R Central air conditioner 5,000 115/230 3 #10 40 1 — FIXED UTILITIES Sump pump 300 115 2 #12 20 1 or more 5-20R Heating plant, forced-air furnace 600 115 2 #12 20 1 — Attic fan 300 115 2 #12 20 1 or more 5-20R TYPICAL WIRING IN WOOD CONSTRUCTION 7.622 INTE R I O R CO N ST RU CT I O N 265 Light allows us to see, grow food, experience emotion, and perform daily functions. Windows, clerestories, and skylights were the lighting tools used for most building types since we have been using buildings for shelter. Since Edison’s bulb, light source efficiency has improved over 100 times; today, 100 times more light can be produced using the same amount of power. Lamp life has improved thousands of times, allowing us to change a lightbulb every 50,000 hours (15 years) instead of every 100 hours (10 days). New light sources such as light-emitting diodes (LEDs) are silicon based and can be computer programmed to change intensity, distribution, and color. Every 6 months, a new lighting technology “leapfrogs” an old one, similar to the way the computer industry has grown in the last two decades. These technological advancements allow designers to illuminate spaces more effectively than ever before. Basic principles of good lighting design have not changed, but the available tools have changed dramatically. A new awareness of design sustainably influences all components of a project. Lighting uses approximately 20% of all energy within a building, and there are many opportunities through careful design to minimize lighting energy use without sacrificing quality. It is a simple task to reduce lighting energy without considering the impact on quality. Lighting standards have traditionally been identified in a quantitative approach of determining how many footcandles are needed. There is a movement in the lighting industry toward more qualitative metrics such as: • How bright should this be? • What happens if I change that wall to a darker color? • How much daylight should I allow into a space before it starts causing too much glare? The challenge for anyone designing lighting for a project is to understand the basic principles and important qualitative issues and apply these in a logical fashion. Light must enhance the environment, allow individuals to perform their tasks, and make our world a safer and better place. QUALITATIVE DESIGN ISSUES Qualitative design issues are as follows: • • • • • • • • • • • • • • • Appearance of the space Color of the space Daylight integration Direct glare Flicker Light distribution on surfaces Light distribution on the task plane Luminance (brightness) of room surfaces Modeling of faces or objects Points of interest Reflected glare Shadows Source/task/eye geometry Surface characteristics Lighting system control Depending on the project, some of these factors may be more important than others. For example, the appearance of a hotel lobby is extremely important, while an industrial factory’s appearance may not be. The color quality of the light in an office space will be more critical than that in a parking garage. Uniform light distribution in a library stack is key, whereas nonuniform lighting in a restaurant is desirable. Answers to these questions usually lead a design in a specific direction. NOTE 7.622 Figure shows typical wiring in wood construction. In metal stud construction, cables are passed through precut openings in place of field-drilled holes. Contributor: Charles B. Towles, PE, TEI Consulting Engineers, Washington, DC. Stephen Margulies, IES, IALD, One Lux, New York, New York. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 266 I N T E R IO R CO NST RU CTION QUANTITATIVE DESIGN RECOMMENDATIONS Qualitative recommenations address the following issues: • • • • Illuminance levels Uniformity Luminance (brightness) Glare ILLUMINANCE LEVELS Illuminance is the measure of incident light on a surface. It is measured in lumens per square foot (footcandles [fc]) or lumens per square meter (lux [lx]). This measure of light is easily calculated using the lumen method or, more accurately, using the pointby-point method. There are also computer programs that are relatively easy to use for more accurate analysis. Illuminance does not determine how bright the surface will appear. If the surface is light in color, then it will appear bright. If the surface is dark in color, then that same amount of incident light will make it appear dark. This surface characteristic is called reflectance and is measured as a percentage of light that is reflected from the surface divided by the light that is incident on the surface. A white surface such as a ceiling tile may be 80% reflective while a medium-dark carpet may be 25% reflective. The higher the surface reflectance the brighter a space will look. How much light we actually need for a specific task has been a difficult question to answer. There are many factors that have an impact on this decision. For example, when reading a document, text size, glossiness of the paper, contrast between the typeface and the paper, and the visual acuity of the individual reading the document all influence how much light needs to be delivered to the document in order to read it. Our aging population usually requires more light because of their loss in visual acuity. This is why the present recommended practice indicates a range of illuminance levels for given tasks, and it is left to the designer to decide how much is right. The current illuminance categories with their associated light level recommendations include: Orientation and simple visual tasks: Visual performance is largely unimportant. These tasks are found in public spaces where reading and visual inspection are only occasionally performed. Higher levels are recommended for tasks where visual performance is occasionally important. Common visual tasks: Visual performance is important. These tasks are found in commercial, industrial, and residential appliILLUMINANCE CATEGORIES AND ASSOCIATED LIGHT LEVEL RECOMMENDATIONS 7.623 ILLUMINANCE CATEGORY LEVEL Orientation and simple visual tasks Common visual tasks Special visual tasks DESCRIPTION LIGHT LEVEL, FC (LX) A Public spaces 3 (30) B Simple orientation for short visits 5 (50) C Working spaces where simple visual tasks are performed 10 (100) D Performance of visual tasks of high contrast and large size 30 (300) E Performance of visual tasks of high contrast and small size, or visual tasks of low contrast and large size 50 (500) F Performance of visual tasks of low contrast and small size 100 (1,000) G Performance of visual tasks near threshold 300 to 1,000 (3,000 to 10,000) NOTE 7.624 The values joined by lines illustrate the maximum recommended luminance ratios between various surfaces. Contributor: Stephen Margulies, IES, IALD, One Lux, New York, New York. Page 266 BUILDING SERVICES cations. Recommended illuminance levels differ because of the characteristics of the visual task being illuminated. Higher levels are recommended for visual tasks with critical elements of low contrast or small size. Special visual tasks: Visual performance is of critical importance. These tasks are highly specialized, including those with very small or very low contrast critical elements. Recommended illuminance levels should be achieved with supplementary task lighting. Higher recommended levels are often achieved by moving the light source closer to the task. The eye adapts to varying brightness very quickly. One can experience this adaptation when exiting a movie theater. When an individual walks out of a dark theater into a brighter lobby, it takes several seconds for the eye to adjust to the new environment. Sometimes this causes momentary discomfort and a loss of visual acuity. The same thing can happen when sitting at a desk viewing a computer screen or reading a paper document. Finishes of walls, furniture, desks, flooring, and ceilings are all affected by this relationship. Other space types that warrant significant contrast ratios include restaurants and hotels; the higher the contrast, the greater the drama. UNIFORMITY Lighting for various visual tasks can be enhanced by lighting uniformity, which is effected by luminaire distribution and spacing. Within any lighted space, the light levels will vary. Spaces that are too uniform lack visual interest, whereas spaces that are extremely nonuniform will look dramatic, which may or may not be appropriate. Even within a single room, the lighting intensity can vary. Uniformity criteria are usually expressed in maximum to minimum values or average to minimum values. This does not determine if the space is bright or not but is an easy method to determine if there will be underlighted areas. Looking at average light levels is not good enough; it is important to look at the distribution of the light. Light levels can vary by as much as 50%, and as long as that variation is gradual, a viewer will probably not perceive the difference. It is not uncommon to have an office space designed to an average of 35 fc (350 lx), with the levels varying from a high of 50 fc (500 lx) to a low of 25 fc (250 lx). This is perfectly acceptable as long as the higher light levels correspond to desk locations and the lower levels correspond to circulation or fringe areas. RECOMMENDED LUMINANCE RATIOS FOR DESK TASKS 7.624 TASK RATIO Between paper task and adjacent computer screen 3:1 Between task and adjacent surroundings 3:1 Between task and nonadjacent areas 10:1 MAXIMUM LUMINANCE RATIOS RECOMMENDED FOR COMPUTER WORKSTATION 7.625 Certain tasks such as those in a library stack or an open-plan office area require very uniform illumination. The lighting at the bottom shelf of a library stack is often found to be 10 times less than the lighting at the top shelf. Systems have been designed to solve this challenging design problem and minimize the variation. Open office areas should have reasonably uniform lighting so that when workstations are moved, a similar light level is produced at all locations. Lighting in a restaurant or hotel lobby should have some variation to create drama and visual interest. Sometimes what is selected to receive less light is as important as what is given more light. Illuminating a wall feature or a table in a restaurant and providing less light in circulation areas is important. Providing uniform lighting for a hotel check-in desk so the guests can easily see the transactions is just as important as providing feature lighting on a piece of artwork or another object or finish. This play of light and shadow is what makes a space successful. LUMINANCE Luminance (brightness) is probably the most important criterion to consider when designing a space. Luminance is what we see. This is the amount of light energy that is reflected off a surface and interpreted by our visual system. Although the analysis of luminance is somewhat complex, it is also very intuitive. If the design of a project uses light-color finishes, then the space will appear brighter than a space with darker finishes given the same amount of produced illumination. It is possible to design for less light and lower power with light finishes. At the same time, it is always desirable to have some variation of brightness in a space to create visual excitement. This factor, called the luminance ratio, is the measure of one surface’s brightness as compared to adjacent surfaces. This is also known as contrast. There are recommendations for luminance ratios for common types of spaces such as offices, but the designer must consider this factor for all types of spaces. The standards established for office lighting are geared more toward visual acuity issues. GLARE There are two different types of glare the lighting designer needs to be concerned about. Direct glare occurs when the light source distributes light directly into the eye of the individual. Extreme cases of this type of glare are experienced when driving at night. The oncoming car’s headlights can cause severe discomfort and at times blinding. Most interior luminaires (lighting fixtures) are designed to minimize direct glare. Some luminaires have significant output at angles greater than 40° above horizontal, and care should be taken to determine how much. Brightness in this high-angle zone should be limited to 100 times the brightness of the zone surrounding it. The best way to avoid the problem is to view all luminaires under consideration; looking at the photometric test of a specific luminaire is also helpful. Reflected glare is not as obvious but just as detrimental as direct glare. This type of glare occurs when light reflected off a specular (reflecting light like a mirror) surface is seen by the eye. A common example of this occurs when reading a glossy magazine with the light source reflected in the page, causing what appears to be a veil in front of the document. This is sometimes referred to as a veiling reflection and reduces the ability to see the task. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 267 BUILDING SERVICES Reflected glare has influenced office lighting solutions for decades because lighting systems were designed to minimize reflections in computer monitors. Low-brightness light fixtures were used that produced light only on the horizontal work plane without any higher-angle lighting. These types of luminaires were effective in reducing reflected glare, but they also produced spaces that appeared dark and unappealing. Most computer screens today are now diffuse; they can even be used outdoors and are less sensitive to the light within the room. This technology advancement has allowed the industry to improve the equipment used for office lighting and provide users with spaces that look brighter and are aesthetically more pleasing. These systems are even more efficient than their predecessors because inefficient louvering systems are no longer required. Another example of reflected glare occurs when illuminating a shiny surface such as a polished marble wall in a public space. It is nearly impossible to light these types of walls without seeing the reflection of the light sources in the stone. It is important to minimize this reflection; that can be done by studying where the light sources are relative to observer locations. DIRECT AND REFLECTED GLARE 7.626 LIGHTING DEFINITIONS • Efficacy: The measurement of the relationship between the • • • • • • • • • • • • • • amount of light and the amount of heat produced by both daylight and electric light sources; measured in lumens per watt (lm/W) Footcandle (fc): A unit of illuminance equivalent to the illumination produced by a source of 1 candle at a distance of 1 foot; equal to 1 lumen incident per square foot Illuminance: The measure of light striking a surface, in footcandles. Illuminance can be measured and predicted using calculations; also called illumination Lamp: The electric bulb or tube within a luminaire Lumen: A measure of the amount of light emitted by a light source or falling onto a surface, regardless of directionality Lumen method (zonal cavity system): A calculation method based on the definition of average footcandles over an area Luminaire: A structure that holds an electric lamp and its socket, wiring, and auxiliary equipment, such as ballasts Luminance: Brightness Luminance ratio: The measure of one surface’s brightness as compared to adjacent surfaces Lux (lx): A unit of illumination equivalent to 0.0929 fc Photometry: The measure of light, especially with respect to a luminaire Photometric report : A report that describes the manner in which light is emitted from a luminaire, presented in an industry standard format Point-by-point method (inverse-square method): A variety of methods used to determine maintained illuminance at a point on a vertical or horizontal surface Reflectance: The ratio of reflected light to incident light Specular reflection: Reflection that occurs on a smooth surface, such as polished glass, stone, or metal INTE R I O R CO N ST RU CT I O N 267 ENERGY CODES All projects must comply with local energy codes. The basis for most energy codes is ASHRAE/IES 90.1. Versions 2001, 2004, and 2007 have been adopted by specific states. It is important to understand which version of this code is required for the project as the requirements have changed over the years. To see which energy code has been adopted by a specific state, go to www.energycodes.gov, where there is a current listing by state. The energy code mandates code minimum lighting controls and allowable power densities for a particular space. Energy codes regulate the amount of power and the duration lights are in use. Most codes require that lights be turned off when spaces are not occupied by use of automatic controls such as occupancy or vacancy sensors and time-controlled circuits. A lighting power budget reduces the wattage of lighting installed in a building. The formula is: Energy Use (kWh) = Power (W) Time (hr) There are two methods of energy code compliance: • Whole-building method: This method assigns a single value to a particular building type and uses that number for the entire gross area of the building. For example, an office building is allowed 1 W/sq ft for a building of 1 million square feet, yielding an allowable interior power allowance of 1 million watts. • Space-by-space method: Each area is calculated, and a unique power allowance is allocated for that area. For example, corridors are allowed 0.5 W/sq ft, open-plan areas are allowed 1.1 W/sq ft, conference rooms are allowed 1.5 W/sq ft, and so forth. Usually, the allowances used in the space-by-space method yield a higher power budget, but this method also requires more analysis. The space-by-space method also has additional power allowances for decorative lighting, visual display terminal (VDT) lighting, casework lighting, and multiple-system lighting as found in conference rooms. According to the ASHRAE 90.1 – 2004 Building Area Method of calculation, office space is permitted 1.0 W/sq ft. NOTE 7.625 Direct glare occurs with a head-up position, while reflected glare happens when eyes are looking down at reading matter. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 268 I N T E R IO R CO NST RU CTION Page 268 BUILDING SERVICES ASHRAE SPACE-BY-SPACE METHOD 7.627 SPACE-BY-SPACE METHOD KEY SPACE NAME AREA TYPE WATTS/ SQUARE ALLOWED FOOT AREA WATTS Office Enclosed 1 Office—enclosed 1.1 227 250 Office Enclosed 2 Office—enclosed 1.1 187 206 Office Enclosed 3 Office—enclosed 1.1 184 202 Office Enclosed 4 Office—enclosed 1.1 183 201 Office Enclosed 5 Office—enclosed 1.1 199 219 Office Enclosed 6 Office—enclosed 1.1 128 141 Office Enclosed 7 Office—enclosed 1.1 127 140 Office Open 1 Office—open plan 1.1 91 100 Office Open 2 Office—open plan 1.1 59 65 Elec/Mech 1 Electrical/ mechanical 1.5 108 162 Elec/Mech 2 Electrical/ mechanical 1.5 18 27 Corridor/ Transition 1 Corridor/transition 0.5 800 400 Corridor/ Transition 2 Corridor/transition 0.5 184 92 Restroom 1 Restroom 0.9 105 95 Restroom 2 Restroom 0.9 139 125 Lounge Lounge/recreation 1.2 149 179 Office Enclosed 8 Office—enclosed 1.1 158 174 SUSTAINABLE LIGHTING DESIGN Lobby 1 Lobby 1.3 240 312 The U.S. Green Building Council (USGBC) has developed the LEED (Leadership in Energy and Environmental Design) project certification process that rates each project for its efforts toward sustainable design. In order for a project to achieve LEED certification, it must satisfy specific prerequisite requirements. The prerequisite for lighting is complying with all of the requirements as stated in ASHRAE 90.1P 2004. Additional voluntary strategies can be pursued to achieve even greater energy savings. Lobby 2 Lobby 1.3 100 130 Conference 1 Conference/meeting/ 1.3 multipurpose 476 619 Conference 2 Conference/meeting/ 1.3 multipurpose 239 311 Total Allowed Watts: 1.01 W/ sq ft — 4,148 Potential Decorative Lighting Allowance: ADDITIONAL VOLUNTARY ENERGY-SAVING STRATEGIES 7.628 CATEGORY Potential VDT Allowance: STRATEGY LEED CREDITS Sustainable sites Light pollution reduction: Prevent spill of light into sky or onto neighbor’s property Use luminaires that produce lighting in a downward orientation. Most decorative lantern fixtures will not comply with this requirement 1/2 to 1 Energy and atmosphere energy use Optimize energy performance Reduce below limits set by ASHRAE 90.1-2004 1 to 6 Commercial interiors: Lighting power 15% below standard 1 New construction: Building energy Total Watts with Special Allowances: 0 1.27 W/ sq ft — 5,203 DAYLIGHT FACTOR 25% below standard 2 30% below standard 3 10.5% below standard 1 14% below standard 2 17.5% below standard 3 21% below standard 4 24.5% below standard 5 28% below standard 6 Indoor environmental quality: Controllability of systems Provide 90% of occupants with control over their lighting; can usually be achieved with user-controllable task lighting at desk 1 Indoor environmental quality: Daylight and views Daylight factor of 2% and direct view of vision glazing (window or skylight) for 75% of floor area 1 Daylight factor of 2% and direct view of vision glazing (window or skylight) for 90% of floor area Add 1 Lamp ratings of mercury content within lamps and analysis tools on manufacturer Web sites can determine whether this LEED point can be achieved — Innovation in design: Low-mercury lamps 1,055 Contributor: Stephen Margulies, IES, IALD, One Lux, New York, New York. Daylight can reduce the amount of electrical energy used for lighting. In meeting the ASHRAE standard requirements, the daylight factor is influenced by: • Size, shape, and transmittance of glazing • Shading from exterior or interior • Ceiling height • Interior finishes • Space planning Blinds, drapes, and shades have no impact on the daylight factor, although they are important in controlling energy use. Geographic location and building orientation are also not considered for the daylight factor. Some spaces may not have usable daylight because of location, but the analysis still needs to be done. ULTRAVIOLET WAVES Ultraviolet (UV) light waves are responsible for skin cancers in human beings. Daylight, which contains UV light, offers positive physical and psychological benefits in interiors, but the amount of direct UV from sunlight should be limited. Some lamp sources, including fluorescent and HID, also emit UV. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 269 BUILDING SERVICES MERCURY All high-efficiency lamps incorporate mercury, which is a neurotoxin that is regulated by the U.S. Environmental Protection Agency (EPA) and various states. When lamps are disposed of in landfills, mercury can find its way into the water supply. It accumulates in the tissue of fish and moves up the food chain, eventually reaching humans. Lamp manufacturers have dramatically reduced the mercury content in their lamps, but significant differences still exist from one product to the next. Local collection for recycling is available for used lamps containing mercury. INTE R I O R CO N ST RU CT I O N 269 FLUORESCENT TUBE LAMP 7.629 LIGHT SOURCES DESIGN CONSIDERATIONS Even though color rendering, lamp life, and efficacy ratings will normally dictate the general choice among incandescent, fluorescent, high-intensity discharge (HID), and LED lamp families, there remain other detailed factors to consider when selecting a specific lamp. SMALL LIGHT SOURCES In general, smaller light sources are much easier to focus, whereas large diffuse sources such as fluorescent tubes are quite difficult to direct. For example, the filament of a low-voltage halogen multifaceted reflector (MR) lamp can be combined with a reflector profile to produce anything from a very narrow spot to a very wide flood. Small lamps with small filaments are usually better suited to task lighting applications where precise control of beam pattern is important. Larger light sources are more appropriate for ambient background and illumination where light levels are fairly even. STRAIGHT-TUBE FLUORESCENT LAMP SHAPES AND TYPICAL NOMINAL LENGTHS 7.630 LUMEN MAINTENANCE AND LAMP LIFE Lamp life is influenced by various factors depending on the lamp technology being considered. Lamp position, operating voltage, operating temperature, and hours per on/off operating cycle also may have a significant impact. Dimming can be used to compensate for lamp lumen depreciation, where lamp power is increased over time. LABEL DESIGNATIONS All lamps have a great deal of information coded into their labeling, but different lamp families use different coding. This information may variously include the lamp shape, wattage, base type and size, lamp tube length in inches, lamp diameter in 1/8-in. (3-mm) increments, reflector shape, color temperature, and beam spread pattern. Here are some examples: • An incandescent A-19 is the common 2.375 in. (60 mm) diameter lamp. • An F25T8SPX30 is a 25 W fluorescent lamp with a T-pin base and a 1 in. (25 mm) diameter bulb operating at a correlated color temperature (CCT) of 3,000 K. • A halogen 250PAR38SP coding designates a 250-W lamp with a parabolic aluminized reflector, a diameter of 4.75 in. (121 mm), and a spot-beam spread pattern, as opposed to a flood pattern. Because manufacturers use slightly different coding, and new products are constantly being introduced, appropriate technical information should always be consulted. Some manufacturers also offer a comparison chart of competing product brand equivalencies. FLUORESCENT LAMPS Fluorescent lamps combine good efficacy, good color, and long lamp life at a reasonable first cost. A high-voltage starting current from the fixture ballast starts a general fluorescent lamp. Each time the lamp is started, an electrical current passes through an inert and electrically nonconductive gas by first evaporating a small drop of mercury held within the tube. The resulting photons of ultraviolet (UV) light are then absorbed by phosphor coatings on the lamp bulb, giving off visible light. The ballast then provides reduced current that maintains the discharge of light. Compact fluorescent lamps (CFLs) come in a wide variety of sizes and shapes, as well as base mounting configurations, and may be either self-ballasted or require an external ballast. The use of triphosphors in CFLs gives them satisfactory color rendering with a color rendering index (CRI) over 80 and CCT in the general range of 2,700 to 5,000 K. CFLs are popular replacements for incandescent lamps because they offer light of about 4 times the efficacy and 10 times the lamp life. They are increasingly competitive on cost, efficiency, and color, even compared with some high intensity discharge (HID) lamp technologies. Fluorescent and HID lamps emit ultraviolet radiation at much lower levels than are found in daylight but still should have UV filters. Fluorescent lamps contain mercury and require special recycling procedures. Consider LEDs as an alternative. INCANDESCENT LAMPS Incandescent lamps generate light by heating a thin tungsten metal filament with electrical current. To prevent oxidation, the filament is sealed in a bulb of inert gas. The typical A-lamp incandescent has a color temperature range from 2,750 to 3,200 K, which is warm and emphasizes reds while dulling blue tints. They have a short life of about 750 to 1,500 hours, but are inexpensive and easy to replace. Incandescent lamps are much less energy-efficient than some other types, and their use is increasingly being regulated. Because incandescent lamps have a small point source of light generated at the filament, effective reflector profiles can be designed into a reflective lamp bulb enclosure or into the fixture housing. This ease of control translates into a good match of beam spread and beam pattern for task and display lighting because light can be placed more specifically where it is wanted. Incandescent lamps can be readily dimmed; dimming reduces the efficacy and color temperature of incandescent nonhalogen lamps slightly, but it greatly increases lamp life. Halogen lamps are a form of incandescent lamp, but differ in the type of inert gas used within the bulb, contributing to extended lamp life. Halogen lamps have a rated life of about 2,000 to 3,000 hours, with very low lamp lumen depreciation. They offer a CRI of 100 at CCTs of 2,600 to 3,600 K. Halogen lighting is most appropriate in applications where precise control and ease of dimming are important, such as display and accent lighting. Fluorescent and other gas discharge lamps have a higher efficacy, so halogen lamps should normally not be used where energy consumption and general room lighting are priorities. Incandescent lamps come in several sizes and shapes. Their generic label takes the form WWSDDBB. Other terms may be used for colored lamps, lamp base, or manufacturer-specific features. • W: Wattage • S: Shape, including general-service A lamps, reflector lamps, elliptical reflectors, PAR (pressed aluminum reflector), candle, globe, and decorative shapes • D: Diameter of the lamp bulb in eighths of an inch • B: Beam spread characteristic (spot or flood), if applicable HIGH-INTENSITY DISCHARGE LAMPS High-intensity discharge (HID) lamp technology includes mercury, metal halide, and sodium gas discharge lamps. In general, they have high efficacy and low to average color rendering. Their most common applications are industrial, commercial, roadway, and security lighting. Metal halide lamps were developed from mercury vapor lamp technology; they are now an excellent match of color, efficacy, and lamp life. CRIs of 70 and 90 are common at CCTs of 2,500 to 5,000 K. Metal halide lamps are appropriate for high-ceiling spaces where lamps are turned on and off at long intervals. Metal halide lamps require relatively long start times. Pulse-start lamps start faster than probe-start metal halides, with a strike time of 1 to 4 minutes and restrike time of 2 to 8 minutes, compared to probe-start times of 2 to 15 minutes and 5 to 20 minutes, respectively. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 270 270 I N T E R IO R CO NST RU CTION LIGHT-EMITTING DIODE LAMPS Light-emitting diodes (LEDs) are less than 1 sq mm (0.0015 in.) in area. They radiate very little infrared (IR) heat and are highly energy efficient. LEDs can be designed to focus light. As replacements for incandescent and fluorescent lighting, LEDs are termed solid-state lighting (SSL) devices and are clustered in arrays of several semiconductors to form a single lamp. Highpower white-light LEDs are used for illumination. LED lamps operate on direct-current voltage and are polarity sensitive; improper connection can destroy them. Otherwise, they have an extremely long life, typically about 10 years. LEDs usually fail by gradual dimming rather than sudden burnout. They are insensitive to vibration and temperature and are shock resistant. Unlike some other highly efficient lamps, LEDs contain no mercury and emit no UV energy. BUILDING SERVICES Induction lamps resemble general-service incandescent A-lamps, but operate like gas discharge lamps. Induction lamps have no strike or restrike time, no color shift with age, and low sensitivity to operating temperature. They do require special fixtures, are not currently dimmable, and may have a pink hue in the first few minutes of operation. At the end of the rated 100,000 hours of life, it may be necessary to replace the entire induction system with its lamp, power coupler, and high-frequency generator. Light source standards include: • • • • Color rendering index (CRI) Correlated color temperature (CCT) Lamp life Efficacy The color rendering index (CRI) has been established to assist the designer in selecting light sources. The CRI rating system is on a scale from 0 to 100. Historically, the more efficient a light source was, the lower the CRI. Halogen light sources have the highest CRI, while low-pressure sodium sources have the lowest CRI. There has been a movement to improve the CRI of all light sources so that good color rendering can be achieved with efficient light sources. MINIMUM LAMP COLOR RENDERING INDEX 7.632 CRI 2,700 Halogen 3,000 Fluorescent 2,700 to 6,500 Metal halide 3,000 to 4,000 LED 2,700 to 6,000 Daylight 5,500 to 7,500 MINIMUM CCT LEVELS 7.634 LAMP CCT, K APPLICATIONS <2,500 Bulk industrial and security (HPS) lighting 2,700 to 3,000 Low light levels in most spaces (<10 fc [100 lx]); general residential lighting; hotels, fine dining and family restaurants, theme parks 2,950 to 3,200 Display lighting for retail and galleries; feature lighting 3,500 to 4,100 General lighting in offices, schools, stores, industry, medicine; display lighting; sports lighting 4,100 to 5,000 Special application lighting when color discrimination is very important; not commonly used for general lighting 5,000 to 7,500 Special application lighting when color discrimination is critical; uncommon for general lighting APPLICATION <50 Noncritical industrial, storage, and security lighting 50 to 69 Industrial and general illumination when color is of minor important 70 to 79 Most office, retail, school, medical, and other work and recreational spaces 80 to 89 Retail, work, and residential spaces when color quality is important 90 to 100 Retail and work spaces when color rendering is critical INDUCTION LAMPS Induction lighting is a rapidly emerging and revolutionary lighting technology. It is essentially fluorescent technology without lamp cathodes. Induction lighting provides approximately 100,000 hours of lamp life, which is about 10 times the life of HID sources, at about 3 times the cost. They offer good efficacy and CRIs of 80 or better at CCTs of 3,600 to 4,000 K. CCT, K Incandescent Some light sources have better color rendering properties than others. The monochromatic spectral distribution of yellow high-pressure sodium (HPS) lighting, which is generally used only outdoors, can make it difficult to determine the color of objects in the field of view. In a retail establishment that is illuminated with halogen track fixtures, all of the colors seem to be vibrant due to the well balanced fullspectrum spectral distribution of this lamp type. Organic light-emitting diodes (OLEDs) are used in television, computer, and small mobile device screens. They are also used as light sources for general space illumination, and for large-area lightemitting elements. Although currently OLEDs emit less light per unit than LEDs, they are likely to become a valuable light source in the near future CCTS ASSOCIATED WITH COMMON LIGHT SOURCES 7.633 LIGHT SOURCE STANDARDS COLOR RENDERING INDEX LED 7.631 The correlated color temperature (CCT) is a reference standard that correlates to a standard color and is identified in kelvins (K). The higher the number, the cooler is the color of light source; the lower the number, the warmer is the color of light source. LAMP LIFE Different light sources reach the end of their useful life at different times. A traditional screw-in incandescent lamp lasts only 750 hours, whereas a new LED light source can last up to 50,000 hours. If the lamps burn 10 hours per day, the incandescent lamp will have to be replaced every 75 days (0.2 year), and the LED light source every 5,000 days (13.7 years). Linear fluorescent lamps generally last 20,000 hours, whereas compact fluorescent lamps last around 12,000 hours and metal halide lamps last 12,000 to 16,000 hours, depending on the specific lamp. Historically, light sources were classified as “warm” or “cool” colors. Certain light sources, such as incandescent and halogen, are only available in a single color. However, there are a variety of light sources for which the apparent color of the light source can be selected from a wide range; these include fluorescent, metal halide, and LED lamps. The selection of light sources depends mostly on the application. Even though LEDs last a long time, they may not be appropriate because of output or cost, although both of these considerations are improving. Specific projects, such as exterior roadway or parking area lighting, require light sources with a long life, because the cost of lamp replacement is extremely high. Most office lighting COLOR RENDERING LUMEN MAINTENANCE CORRELATED COLOR TEMPERATURE LIGHT SOURCE COMPARISON 7.635 SOURCE BALLAST/ TRANSFORMER OPERATING POSITION RESTRICTIONS EFFICACY, LM/W LIFE, HR OPTICAL CONTROL START TIME TO FULL OUTPUT Incandescent No None to few Very good Low 750 to 1,000 Good Good Instant Tungsten halogen No None to few Good to very good Low 2,000 to 3,000 Good Very good Instant Fluorescent Yes None Fair to very good High to very high 18,000 to 24,000 Fair to good Fair to good Instant to fast Compact fluorescent Yes None to few Very good High 10,000 to 20,000 Good Fair to good Fast Neon/cold cathode Yes None — Moderate 25,000+ Good Poor Fast Deluxe mercury Yes None Fair Moderate 24,000+ Fair Poor 7 to 9 min Metal halide Yes Some Fair to good High 10,000 to 20,000 Poor to fair Good 5 to 10 min High-pressure sodium Yes None Poor to fair High to very high 24,000+ Fair to good Good 3 to 5 min White sodium Yes None Good High — Good Good 3 to 5 min Ceramic metal halide Yes None to some Good Moderate to high 10,000 to 20,000 Fair to good Good 5 to 7 min Low-voltage halogen Yes None Good to very good Low 2,000 to 4,000 Very good Very good Instant LED No None Very good Very good 35,000 to 30,000 Very good Very good Instant Contributor: Stephen Margulies, IES, IALD, One Lux, New York, New York. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 271 BUILDING SERVICES projects use fluorescent lighting because of its low first cost, good color, and reasonably long lamp life. LED lamp life is very dependent on thermal conditions; the hotter the environment, the shorter the lamp life. When considering LED lamps, be very careful in determining the application. INTE R I O R CO N ST RU CT I O N 271 LIGHTING TOOLBOX 7.636 TYPE APPLICATION Recessed downlight General lighting for circulation and public spaces Recessed wall washer Feature lighting for vertical surfaces Recessed accent light Feature lighting for objects Recessed troffer General ambient lighting Linear pendant indirect General ambient lighting Linear pendant direct/indirect General ambient lighting Strip light Utility fixture used in architectural linear coves for wall and ceiling lighting Recessed linear wall washer Feature lighting for vertical surfaces Track light Feature lighting for objects EFFICACY Efficacy is the measure of the efficiency of a light source. There are other factors that have an impact on overall system efficiency, including luminaire efficiency (how much light comes out of the optical device) and ballast or power supply efficiency. Overall system efficiency begins with how much light is emitted from the lamp for a given amount of electricity. This is measured in lumens per watt, where the lumen is the most basic unit of light energy and watts are a measure of power. Incandescent light sources are highly inefficient, because they provide only 15 lm/W; by contrast, fluorescent light sources produce up to 85 lm/W. To put this into perspective, a single 65 W incandescent lamp in a 10 by 10 ft (3 by 3 m) room will produce approximately 5 fc (50 lx). Two 32 W fluorescent lamps that use the same wattage as the 65 W incandescent lamp will produce approximately 30 fc (300 lx). For the same amount of power, the fluorescent solution provides six times the amount of light. Metal halide light sources produce around 80 lm/W, and halogen light sources produce approximately 20 lm/W. Federal legislation has been enacted that will phase out the traditional incandescent lamp in the next few years. LED light sources continue to improve in efficacy every few months. Manufacturers are now claiming around 30 to 40 lm/W for good color quality white light. LEDs are expected to achieve 150 lm/W within the next 5 years. When LEDs reach this efficacy, they will probably replace many older light sources for suitable applications. TOOLBOX Just like a carpenter has a toolbox with an assortment of tools to perform specific tasks, the lighting designer has an assortment of the most commonly used lighting tools in his or her toolbox. Most lighting tools can use a variety of light sources, depending on the application. REFERENCE IMAGE 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 272 I N T E R IO R CO NST RU CTION LIGHT COVE—6 IN. (152 MM) WIDE, 8 IN. (203 MM) MINIMUM CLEARANCE 7.637 Page 272 BUILDING SERVICES MIRROR LIGHT 7.640 COMMUNICATIONS SYSTEMS TELECOMMUNICATIONS SYSTEMS ASSISTIVE-LISTENING SYSTEMS Stadiums, theaters, auditoriums, lecture halls, and similar fixedseating assembly areas are required to provide assistive-listening systems if these locations have a capacity of more than 50 persons and fixed seating or if an audio amplification system is provided. Portable systems may be acceptable. 2010 ADA Standards for Accessible Design require that signs should be provided at each covered assembly area or ticketing areas to indicate the availability of the assistive-listening system. ACCESSIBLE TELEPHONES Wheelchair-accessible telephones are required by the ADA/ABA Accessibility Guidelines where public telephones are provided. One wheelchair-accessible phone is required on each floor or level where phones are provided; where more than one bank (three or more phones) is provided on a floor or level, at least one phone at each bank must be wheelchair accessible. At least one phone per floor or level must allow forward approach. Federal regulations require all new telephone equipment to be hearing-aid compatible. Clear floor space, unobstructed by bases, enclosures, or seats, is required for wheelchair-accessible telephones by the ADA/ABA Accessibility Guidelines. Telephones, enclosures, and related telephone book storage cannot encroach on the required clear floor space, and must comply with the provisions for protruding objects. LIGHT COVE—DOUBLE SIDE SOCKET T8 STRIP 7.638 INTERIOR WHEELCHAIR-ACCESSIBLE TELEPHONE REQUIREMENTS 7.641 NUMBER OF TELEPHONES PROVIDED ON A FLOOR OR LEVEL 1 or more single units EXIT AND EMERGENCY LIGHTING RECESSED LIGHT COVE 7.639 Emergency lighting is required in almost every type of nonresidential occupancy. Emergency lighting is used in the event of a power failure to provide adequate lighting so that the occupants can safely exit the building. Emergency lighting can be accomplished with either dedicated, “normally off” light fixtures that use integral batteries for power or “normally on” fixtures that are part of the architectural lighting system and are powered from the building’s emergency generator or uninterruptible power supply (UPS) system for full light output. Alternatively, fluorescent fixtures can use integral inverter battery packs that provide significantly less than full light output. These inverter packs come in various lumen output ratings, and care must be taken to determine the appropriate unit. Emergency light level requirements vary throughout the country but the most common requirement is 1 fc (10 lx) average measured at the floor as required by NFPA 101. Local requirements must be checked. The areas that require emergency lighting can also vary throughout the country. Some codes only require emergency lighting in the paths of egress, and some require emergency lighting everywhere. Contributors: Stephen Margulies, IES, IALD, One Lux, New York, New York. Vali Sorell, PE, Syska Hennessy Group, Inc., Charlotte, North Carolina. William R. Arnquist, AIA, Donna Vaughan & Associates, Inc., Dallas, Texas. Larry O. Degelman, PE, Texas A&M University, College Station, Texas. Walter T. Grondzik, PE, Florida A&M University, Tallahassee, Florida. MINIMUM NUMBER OF WHEELCHAIR-ACCESSIBLE TELEPHONES 1 per floor or level 1 bank 1 per floor or level 2 or more banks 1 per bank WHEELCHAIR-ACCESSIBLE TELEPHONES 7.642 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 273 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 273 • The number of people who will be required to view the image • The worksurface requirement, if any, for any or all of the audience • Code requirements for ingress, egress, and accessibility GUEST ROOMS WITH COMMUNICATIONS FEATURES PRESENTATION ROOM LAYOUT In guest rooms that are required to provide communications features by the ADA/ABA Accessibility Guidelines, it is advisable to consider ensuring compatibility with adaptive equipment used by people with hearing impairments. To ensure communication within the facility and on commercial lines, provide telephone jacks that are compatible with both digital and analog signal use. Once the users’ needs are determined, the driving parameters behind a presentation room layout are: AUDIOVISUAL SYSTEMS FRONT- AND REAR-PROJECTED IMAGES AND MARKING SURFACES 7.643 Audiovisual (AV) presentation facilities include various types of presentation and conferencing spaces where audio and video content are utilized as a part of the room’s function. The impact on the space includes not only the AV cable pathways and electronics but also the size, shape, layout, and finishes of the space that support the AV functions. The size, type, and location of displayed images must be determined so that the space supports the presentation for the intended audience, and any seating areas must be designed for acceptable viewing. In addition, the acoustical environment must be considered for the aural components of the presented material. • The image size required based on the images to be viewed and the detail viewing needed • The image aspect ratio required based on the users’ content Creating an optimum AV room layout is an iterative process based on the above parameters for both new and existing spaces. LOCATING AV SPACES The location of spaces that include AV functionality must be considered with respect to the aural and visual requirements of the space and the electronics. The location of a conference room on a southern-facing exterior glass wall of a building in the northern hemisphere will require attention to daylight control for the video display to be usable. Likewise, interior AV spaces with glass walls may require visibility control for both lighting and privacy issues. Acoustical issues must also be considered to avoid excessive background noise in the AV space. Consider locating occupied AV spaces away from mechanical rooms, electrical rooms, machine rooms, and other noisy spaces. Also consider heating, ventilating, and air conditioning (HVAC) service to the space to reduce noise from HVAC terminal devices that may be located above or inside the room. Typically, AV presentation spaces should be designed for a noise criterion (NC) rating of 30 to 35, which is an indicator of the background noise level. Spaces with a videoconferencing function should be designed for NC 25 to NC30 background noise. TRADITIONAL BLACKBOARD PRESENTATION MODE 7.644 PRESENTATION ROOMS There are a wide variety of spaces that may be considered presentation rooms: training rooms, lecture halls, classrooms, boardrooms, and auditoriums are common examples. These spaces typically share common AV requirements of image presentation along with audio media playback of program material and possibly speech reinforcement, depending on the size of the space. Within each of these categories, there are some common requirements. Presentation furnishings include easels, lecterns, and portable sound systems. An audiovisual presentation system often includes the following equipment: • • • • • • • Video display (video projector, flat-screen video display) Microphones, loudspeakers, and amplifiers Routing switcher (becoming less common) Remote control system A computer, for presentations or to browse the Internet Projector hookup for a portable notebook computer Document/object camera, for use with printed documents or small objects (becoming less common) • Video equipment, including monitors, digital video disc (DVD) players, and camcorders Typically, each of these components is provided by a different manufacturer. AV integrators combine these various components and ensure that they are properly installed. For viewing images, the application and type of content should be determined. For example, legibility of displayed characters and symbols is of critical importance for instructional material in educational and other settings. In some spaces, more detailed image viewing may be required, such as in medical or military facilities. This will impact the image sizing requirements. For the audio components, the need for audio program material must be considered in terms of numbers of channels of playback (e.g., monaural, stereo, or surround sound), and the need for reinforcement of speech must be determined (e.g., in a large house of worship or an auditorium). Contributors: Flack & Kurtz, Consulting Engineers, New York, New York. Del Shuford, AIA, Gensler, Dallas, Texas, and Timothy W. Cape, CTS-D, Technitect, LLC, Decatur, Georgia. Jeffrey E. Bollinger and Jason Martinez, Acentech, Inc., Cambridge, Massachusetts. IMAGE SIZING 7.645 TASK DESCRIPTION VIEW CALCULATION General instruction and presentation Video, PowerPoint, and general static images, with text using font sizes greater than 18 points Farthest Viewer = 6 Height Detailed viewing tasks General instruction and presentation Farthest Viewer = 4 Height Detailed images or smaller font sizes Viewing Web pages, software training with 10- to 12-point text, computer programming instruction, medical image viewing, and mapping All tasks — VIDEOCONFERENCE PRESENTATION MODE 7.646 Closest Viewer = 1 Width 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 274 I N T E R IO R CO NST RU CTION Page 274 BUILDING SERVICES REAR-SCREEN PROJECTION PROJECTION ROOMS Rear-screen projection has several advantages over front-screen projection. It is more forgiving of incident ambient light so that acceptable contrast of the displayed image is possible, even with some light spilling onto the screen. Front-projection screens, on the other hand, reflect all incident light back to the audience, which directly reduces the contrast ratio of the displayed image. Rear projection involves the use of a translucent projection surface (usually mounted in a wall frame) with a room dedicated to the video projector(s), sometimes also housing racks of other AV equipment. In this case, appropriate space must be allocated for the video projector, its mount, and any other electronics that may be located in the space. A rear-projection room should always be provided with flat black wall, floor, and ceiling finishes. Rear-screen systems require a projection booth behind the screen, which takes up valuable floor space, but if space allows, it is often a preferable approach. With the use of one or more mirror bounces between the projector and the screen, the depth of the booth can be reduced to a much shallower space than would be required without the folding of the light path by the use of mirrors. AV SUPPORT SPACES For a complete AV system, audio and video components mounted in the space with the user include equipment such as video displays, loudspeakers, microphones, cameras, connector plates, and control user interfaces. In addition, other devices will often be located outside the main user space. These may include AV control rooms, equipment rooms, and rear-projection rooms. AV CONTROL ROOMS Separate projection booths, whether for rear-screen or forwardscreen projection, generally require more space than if the projector is located in the room itself. An enclosed projection booth provides a quieter environment, because the projector and other equipment that has cooling fans are enclosed separately. It also offers some advantage for equipment security, because the equipment is not exposed within the room and does not move around on carts within the building. The booth may, however, require an operator within the room, as well as a means of communication between the operator and the presenter. LARGE-SCREEN DISPLAYS For large-screen display of video images, current technologies include: For users and systems that require hands-on control or user support, there may be an AV control room that houses both AV technical personnel and AV equipment racks and other equipment. An AV control room may also serve as a projection room for front-projection systems, especially in larger spaces such as auditoriums. • Liquid crystal displays (LCDs) • Digital Light Processor, a proprietary digital micromirror display • Digital image light amplifier (DILA) AV EQUIPMENT ROOMS Flat-panel displays are increasing in size as manufacturing methods improve. As of this writing, the largest LCD flat panel is about 108 in. (2,693 mm) diagonal. When displaying 45 lines of text, this size image is legible to a viewing distance of about 30 ft (9.1 m) under ideal conditions. For longer viewing distances, projection is generally required to deliver good legibility. However, if a limited ceiling height does not allow for a large enough image size for the most distant viewer, then the system solution can include several small displays arrayed farther back in the audience area, either ceiling mounted or wall mounted, giving a shorter distance between any given viewer and the nearest display. This approach has the disadvantage of causing the audience to shift their focus of attention between a presenter in the front of the room and a display that is likely to be off to the side. AV systems serving a particular space may have their supporting equipment located inside the room in a lectern, credenza, or inroom electronics rack. In other cases, the supporting equipment (audio/video routers, codecs, control system processors, audio mixers, amplifiers, etc.) may be located in an AV equipment room. AV EQUIPMENT RACK MOUNTING 7.647 Other technologies for ultra-large images include laser projection and the use of light-emitting diodes (LEDs). Digital echo cancellers are used with the microphones and loudspeaker system to help provide an echo-free sound quality. In distance-learning applications, a camera that can automatically track the movements of the instructor is often employed. Contributors: Del Shuford, AIA, Gensler, Dallas, Texas, and Timothy W. Cape, CTS-D, Technitect, LLC, Decatur, Georgia. Harry Spielberg, Cosentini Associates, New York, New York. Jane Clark, AIA, Zimmer Gunsul Frasca Partnership, Seattle, Washington. Jim Johnson, Wrightson, Johnson, Haddon & Williams, Inc., Dallas, Texas. Jeffrey E. Bollinger and Jason Martinez, Acentech, Inc., Cambridge, Massachusetts. ACCEPTABLE VERTICAL VIEWING AXES 7.648 VIEWING AREA CRITERION Horizontal optimum Within 45° off either side of the image centerline Horizontal acceptable Within 45° off either side of the image edge in plan Vertical from eye level Maximum 15° up to center of image Maximum 30° up to top of image SIGHT LINES The vertical viewing angle is the angle from the viewer’s eyes to the top of the image. For the optimum sight line, it should not exceed 30° to 35° above the horizontal. Vertical sight line studies provide information about how the image area relates to both the seating area and the projectors in projected-image configurations. The typical concerns are that the screen should not be too high above any viewer, and that video projectors are not too far above or below the screen, which could require optical or electronic corrections for the image to display properly. Another concern is simply the avoidance of obstacles between either the audience and the display or a projector and the screen. Many video projectors are available with optional lenses that allow placement toward the front or at the center or rear of the room. The majority of video projectors are designed to be elevated so that the lens is approximately aligned with the top or bottom of the image. For rear projection, the lenses are often designed to allow the projector to be on the axis of the screen center. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 275 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 275 SIGHT LINES WITH FLAT FLOOR 7.649 SIGHT LINES WITH STEPPED FLOOR 7.650 SIGHT LINES FOR TWO-ROW OVERVIEW 7.651 HUMAN FACTORS AND AUDIOVISUAL DESIGN The design of an audiovisual facility within a finished interior space presents a specific set of multidisciplinary challenges that must be considered to ensure a successful system solution. Most AV systems have elements that affect the following trades and disciplines: • • • • • • • • • • Architecture and interior design Electrical Information technologies Telephony Heating, ventilating, and air conditioning Low-voltage cabling Lighting Acoustics Structural Ergonomics In order to address the issues relating to the integration of audiovisual hardware into the architectural space, the starting point for any AV system should be in the domain of ergonomics and human factors, addressing the means and methods and dimensions to be used to deliver visual and audible information to people gathered in a room, whatever the dimension. Fundamental rules apply whether it is a small meeting room or a large auditorium. The design should initially be considered from the standpoint of an audience member who is receiving visual and audible information from a live presenter or through a display and sound system. The two primary design goals are intelligibility and legibility. Intelligibility defines the degree to which an audience member can NOTE 7.651 Minimum sight lines should be based on a two-row overview. This assumes that viewers can see between the heads of the people seated in the row directly in front of them. Contributors: Jeffrey E. Bollinger and Jason Martinez, Acentech, Inc., Cambridge, Massachusetts. Del Shuford, AIA, Gensler, Dallas, Texas, and Timothy W. Cape, CTS-D, Technitect, LLC, Decatur, Georgia.. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 276 I N T E R IO R CO NST RU CTION clearly understand the spoken word of a presenter or recorded material, as measured by the articulation loss of consonants. Legibility relates to how well each audience member can comfortably read displayed words, numbers, and graphic elements. The design parameters are first considered from the most distant viewer position, which is the worst seat in the house. If the person in the farthest seat can see and hear clearly, then all closer seats will naturally be within acceptable margins. AUDIO INTELLIGIBILITY Equally important in AV design to having clear line of sight and legibility for the displays is the intelligibility of the spoken word. The sound system should be designed and located to deliver crisp, clear audio, free from any howling feedback or artifacts that degrade the ability to understand. The target for the sound system is to deliver audio at 10 to 20 dB above the ambient background noise. This is achieved by using the proper types and directionality of speakers based on architectural surfaces, room shape, and seating areas. Many architectural factors affect the clarity of the sound system, including: • Cubic footage of space, which affects how long the reverberation or echo is from walls, floor, and ceiling • Surface finishes, which provide a degree of sound absorption that reduces reverberation • Dimensions of the ceiling, which affect the distance between a microphone and speakers, thus having an impact on the amount of loudness that can be achieved before howling feedback occurs • Curved walls, which focus sound into hot spots and dead spots • In large spaces, the width-to-length ratio of the room should not be a perfect multiple or harmonic, which may cause standing waves bouncing between surfaces; these negatively affect intelligibility • Noise caused by HVAC fans and ducts, which adds to the background noise Typically, the room criterion (RC) defines the amount of background noise that is acceptable for different types of spaces that include AV systems. It is essential to submit the target RC levels to the HVAC engineers early in the design process to ensure that the system delivers the required noise levels. The lower the target number, the more costly are the methods used to achieve the goal. NOTE 7.652 Speaker layout and density are based on ceiling height and required coverage; lower density may be acceptable for less critical applications. Contributor: Flack & Kurtz, Consulting Engineers, New York, New York. Page 276 BUILDING SERVICES SPEAKERS AND MICROPHONES VIDEO SYSTEMS Speaker placement is very important for the proper operation of a videoconference space. Program loudspeakers are often placed to the left and right of the video displays to provide high-quality sound reproduction, similar to that of a home stereo system. Speakers recessed in the ceiling are most often used to reproduce sound such as voices from the remote conference site. Their placement and operation require careful setup and adjustment of a digital audio processor, including echo canceling, level control, and equalization. The major components of a video system are: Microphones are placed at strategic locations in the videoconference space, preferably: • On tables, for primary participant involvement • On a stand, for secondary participant involvement • Wireless, for a presenter or moderator SPEAKER LAYOUT AND DENSITY 7.652 • • • • • • Camera, lens, and mount Lighting system Transmission system Synchronization system Video switching equipment Video recorder, video monitor, and video controller Digital video systems consist of Internet Protocol (IP) addressable cameras, digital video recorders, network video management systems, monitors, and network video management software. Digital video systems are network capable, and video can be transmitted across local area networks (LANs) and wide area networks (WANs) to a centralized location and multiple network workstations. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 277 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 277 CEILING-MOUNTED PROJECTOR AND SCREEN 7.653 VIDEO TELECONFERENCE COMPONENTS 7.654 NOTE 7.653 Distance of the projector from the wall is variable based on screen size and projector/lens selection 7.654 Keep camera as close as possible to eye height. VIDEOCONFERENCE ROOM 7.655 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 278 I N T E R IO R CO NST RU CTION PROJECTION SCREENS Projection screens can be fixed, motorized, or manual. Motorized screens are more expensive and require some maintenance, but they are less prone to jamming than manual screens. Screens are available that have tensioning cables along the sides, which keep the screen flat, in order to avoid distortion of the image; these are especially useful for larger roll-downs or for critical imagery. The location of projection screens should be coordinated with lighting locations to avoid light spills onto the screen. Recommended screen shapes (aspect ratios) should be based on width-to-height ratios of: Page 278 BUILDING SERVICES • 4:3 for standard video; 16:9 for high-definition video (such as wide-screen DVDs) • 1:1 for slides (where both vertical and horizontal orientations will be used) CONFERENCE CENTER COMMUNICATIONS Conference center communications commonly include long-distance learning, videoconferencing, television distribution, telephone, and Internet connections. Special features are required for • 4:3, 5:4, or 16:9 for computer images CONFERENCE ROOM FOR AV PRESENTATIONS AND VIDEOCONFERENCES 7.656 Contributors: Robert Martino, Shen Milsom & Wilke, Inc., New York, New York. Polysonics, Washington, DC. Harry Spielberg, Cosentini Associates, New York, New York. Richard H. Penner, Conference Center Planning and Design: A Guide for Architects, Designers, Meeting Planners, and Facility Managers, Watson-Guptill Publications, New York, 1991. functions such as videoconferencing, and future needs should be considered when designing for future technology. A control room may be required for receiving outside signals, recording, and transmitting programs throughout the facility and to other locations. The construction of conference center audiovisual presentation rooms requires special consideration. Locations of the rooms, privacy, acoustics, and other concerns should be addressed. Exterior light and noise should not interfere with presentations. If walls are glazed, provide blackout shades to eliminate glare. Zoned lighting should be used to allow for dimming or turning off light fixtures near video displays and projection screens. Noise from the exterior should be reduced to less than 35 dBA to minimize distractions. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM Page 279 BUILDING SERVICES INTE R I O R CO N ST RU CT I O N 279 TIER-STYLE CLASSROOM FOR DISTANCE LEARNING 7.657 Reverberation should be maintained at less than 0.8 seconds for improved acoustics. A gypsum board ceiling in the front half of the space may be a useful sound reflector, amplifying sound to the audience. Nonrectilinear room shapes, especially circular and elliptical forms, may affect acoustics; consult with an acoustical engineer. LECTERN—READER’S SIDE 7.659 MANUALLY ADJUSTABLE LECTERN 7.660 The HVAC RC range should be kept as low as possible for greater speech intelligibility: 20 to 35 is a desirable range (although RC 20 is almost never a realistic goal in a conference center environment); 30 is acceptable if the project faces budget constraints. Allow sufficient space above ceilings for ductwork to be in round or nearly square cross sections. Flat, wide ductwork may be noisy if the wide sections of sheet metal vibrate. VIDEOCONFERENCE ROOM SIZES 7.658 CAPACITY ROOM SIZE APPLICATIONS 1 to 2 Workstation or desk Informal meetings Interviews Research Development 2 to 3 9-0 12-0 (2,745 3,660 mm) General business meetings Interviews Progress meetings 3 to 5 11-0 16-0 (3,350 4,880 mm) General business meetings New business development Group sales meetings Product demonstrations 6 to 8 15-0 17-0 (4,570 5,180 mm) General business meetings Branch site meetings Capabilities demonstrations Source: lauckgroup, Dallas, Texas. AUDIOVISUAL AND PRESENTATION EQUIPMENT LECTERNS AND PULPITS A lectern is a reading desk with a slanting top on which books, documents, or other materials are placed for reading aloud. The height and/or slant may be adjustable. It should be noted that the term podium is often used incorrectly as synonymous with lectern. A podium is a raised platform, whereas a lectern is a stand that serves as a support for notes of a speaker. More complex units may serve as microphone stands, sometimes with integrated computer and recording systems, in academic lecture halls. Many lecterns have built-in control panels for managing the audiovisual media, lighting, draperies, and other technological instruments. These can be custom made, or a control panel can be specified for the manufacturer to install in a prefabricated unit. Some provide space for mounting equipment, such as computers, videocassette recorders (VCRs), and DVD players. Academic lecterns are often attached or integrated into a large desk to accommodate supporting material. Contributors: Jeffrey E. Bollinger and Jason Martinez, Acentech, Inc., Cambridge, Massachusetts. Norman Jaffe, FAIA, Bridgehampton, New York. Gulzer Haider, Carlton University, Ottawa, Canada. In a church, a lectern serves as a stand for the Bible for scriptural readings; it is usually placed in front of the pews, facing the congregation. Where there is also a pulpit used for sermons, the lectern is often placed on the opposite side of the altar. Historically, the pulpit (Protestant) has been a fixed chancel/sanctuary furnishing. However, increasing demand for multiple uses of worship space often requires that all furnishings be movable. Among the most important features of a pulpit is an adjustable top, to accommodate the different heights of speakers. A drop-down step may also be desirable. A pulpit should include a concealed reading lamp (especially where room darkening is employed), audiovisual controls, and a built-in clock. Although lavalier (wireless) mircrophones are used extensively, it is important to provide a concealed microphone cable raceway and pad the pulpit top, to minimize the noise of rustling notes, which may be amplified by sensitive microphones. PROJECTORS The convenience of instant display of computer images, Web pages, DVDs, and videotapes is making the video projector the standard equipment in most rooms, displacing overhead projectors and slide projectors. With ceiling-mounted or ceiling-recessed projectors, video signals are transmitted to the projector through one or more coaxial cables. The projector can be remotely controlled, so access to the projector is required only for maintenance. Several manufacturers of retractable projector mounts provide a recessed ceiling installation. These are more costly than exposed projector installations and require access for maintenance, but offer a clean-looking ceiling when the projector is not in use. Exposed installations will require some space below the ceiling, to permit the lens to be at the same height as the top of the image on the screen. The distance required for the projector to be hung below the ceiling is a function of the height of the top of the image area of the screen relative to the ceiling. This must be considered when determining ceiling heights and sight lines.. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:33 AM 280 I N T E R IO R CO NST RU CTION SECURITY SYSTEMS DEFENSIBLE SPACE Defensible space can be created not only through the provision of a hardened perimeter of physical barriers but also through the use of architectural transitions used to define spaces. In transitioning from a public to a private space, the following architectural devices can be implemented: • • • • • Page 280 BUILDING SERVICES security desk location should be designed to allow for simultaneous monitoring of security equipment and surveillance of all building access points. A fire command room is often required near the firefighters’ point of entry to the building. Location of the security desk in close proximity to this room is also desirable. BUILDING ACCESS FLOOR LAYOUT 7.662 STAIRWAY SECURITY Stairs can cause significant security problems in multitenant buildings. Stairs accessible from an unsecured space (for instance, the exterior) may act as a shelter for the homeless or as a hiding place for criminals, or may provide an unprotected means of access between floors and an avenue for removing property from the building. To mitigate these problems, stair access should be carefully controlled and monitored. Access to the stairs should be controlled at the exit level. Stair doors to the exterior may be established as exit-only or outfitted with delayed-egress devices to discourage use. Stairs below and above the exit level should not directly connect if the lower levels are not secure. Stairs used for access to service spaces should be separate from fire stairs, where possible. Setbacks surrounding the perimeter Flooring material change Floor height increase Ceiling height decrease Narrowing a passage The arrangement of furnishings within a space can promote a sense of defensible space on the interior in the same manner that landscaping can on the exterior. Walls surrounding secured spaces should be installed deck to deck. Mechanical shafts or chases may provide an unprotected means of access between floors. Cameras and motion sensors may also be desirable for monitoring activity in the stairs. They should be positioned to enable security personnel to, first, identify perpetrators, and, second, give them sufficient time to reach the exit before the intruders can escape. SURVEILLANCE STRATEGIES TERRITORIALITY NATURAL SURVEILLANCE Where humans have a sense of ownership in the property they occupy, and outwardly express this instinct through care and defense of that property, less crime is perpetrated against them. Good maintenance and upkeep are the hallmarks of a well-cared-for property. Where this is lacking, crime and vandalism are likely to follow. Natural surveillance is affected by the layout of walls, windows, and furnishings, as well as the amount of light. To increase surveillance opportunities, design open space plans with clear lines of sight. Provide windows for viewing outside the perimeter, particularly at access points. Determine and eliminate hiding places. This can be a challenge to the design professional in a program that also calls for openness and a great deal of public or community space. The design professional can promote the territorial instinct by creating a sense of the unique for a place’s occupants, selecting materials that are resistant to wear and vandalism, and erecting signage to indicate that the area is protected and that access is allowed for authorized users only. Adequate lighting is critical. The lighting levels for certain periods of operation are often overlooked. Emergency lighting should be used to maintain appropriate minimum levels. Areas under closedcircuit television (CCTV) surveillance should be sufficiently illuminated at all times. LOBBY SECURITY MINIMUM INTERIOR LIGHTING LEVEL RECOMMENDATIONS FOR SAFETY 7.663 In general, building lobbies represent semipublic spaces. Visitors and deliveries are received here, and in some high-rise facilities, the lobby level is occupied by retail establishments. Security in the main lobby serves to control access to the upper floors and restricted areas of the building. A 24-hour security desk within the lobby provides an excellent means for security monitoring and response. In smaller buildings, this may serve as the primary monitoring location. The lobby and SECURE LOBBY LAYOUTS 7.661 SPACES FOOTCANDLES General 0.5 LUX 5 Elevation change (e.g., loading dock) 1.0 10 Entrances and stairs 2.0 20 Hazardous areas (e.g., machine room) 5.0 50 ELECTRONIC SURVEILLANCE SYSTEMS Electronic surveillance systems allow monitoring of spaces in and around a building. The system is composed of field devices used to collect, distribute, monitor, and record signals. Cameras and microphones are used to collect images and produce a video/audio output signal. This signal is then distributed to monitoring and recording equipment, usually through a video management device. Monitors or closed-circuit television (CCTV) are used for real-time viewing and playback of recorded video. They come in a variety of technologies, configurations, mounting options, and resolutions. PERIPHERAL DEVICES Peripheral devices include cameras, thermal imaging cameras, and digital video recorders (DVRs). Cameras are classified as either fixed or movable. Source: Protection of Assets Manual, POA Publishing, Los Angeles, California, 1999. • Fixed cameras provide a fixed field of view (FOV). • Movable cameras allow the view to be modified by panning the camera left and right, tilting it up and down, and zooming in and out with the lens. Thermal imaging cameras are devices that sense waves of thermal energy (infrared radiation) and convert them into a viewable image of black-and-white shades. Hottest objects will be viewed as white, coolest as black. Thermal imaging cameras do not require illuminators to operate and are less affected by weather and darkness than other cameras. Contributor: Jeff Schroeder, Kroll Security Services Group, Bastrop, Texas. 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:34 AM Page 281 BUILDING SERVICES ELECTRONIC STRATEGIES Electronic security strategies include providing equipment that can reduce staffing needs or operational costs, creating a database of activity that includes access and alarm events and video records, and providing a means to centrally monitor and administer the system equipment. Electronic security systems are divided into three types: field devices, multiplexing and processing equipment, and administration and monitoring equipment. FIELD DEVICES Field devices consist of switches, sensors, card readers, locks, cameras, and communications devices. SECURITY EQUIPMENT CLOSET—LARGE 7.664 The smallest console rooms are about 80 sq ft (7.4 sq m). The average console room and adjacent equipment room is several hundred square feet. Larger facilities will have a control room approaching 1,000 sq ft (93 sq m) and perhaps a security suite of several thousand square feet. SECURITY DESK DESIGN There are three common options for security desk design: standard equipment racks, a custom desk, or a hybrid (custom surfaces built around standard modules). Standard equipment is recommended for the typical console; custom and hybrid designs can be expensive and should be reserved for special high-end applications. Whether the operator will stand or sit will determine the overall dimensions of the console. In lobbies, the operator should be able to view the lobby area over the console. It is also preferable that the operator be at or above eye level with the public when interaction is expected. A dais may be used to raise the console, or if the operator will sit, an adjustable chair can be used. These factors generally require that the portion of the console above the counter be less than 18 in. (457 mm) high. SECURITY CONTROL ROOM DESIGN Designing the security control room requires review of all aspects of architectural design. The number of individuals and quantity of equipment that the room will be required to house will govern its overall size. Most control rooms are designed for one or two operators. Provisions for the following equipment should be considered: • • • • • • • • • • • • • • Security monitor, keyboard, and printer Card enrollment workstation with card supply Key control cabinet Door controls CCTV monitors, control keyboard, switchers, multiplexers, and recorder Video review workstation Security and elevator intercoms Radio base station Telephones Auxiliary system monitoring and control equipment for fire alarm, elevator, HVAC, lighting, and so on Files and binders for security policies and procedures, guard post orders, shift schedules, event logs, system and equipment operating manuals Lost and found First-aid equipment Traffic cones and temporary barriers SMALL SECURITY DESK LAYOUTS 7.665 ADMINISTRATION AND MONITORING EQUIPMENT The aggregate size of security systems administration and monitoring equipment varies greatly from the partial floor tenant to the large multiuse facility. In the smallest of facilities, the equipment should be placed in a secured location that is readily accessible to its administrator on a daily basis. Common locations are within the local area network (LAN) room or facility administrator’s office. Where a regular security presence justifies a dedicated room, it should be located on the primary access level, near the core or main access point of the facility. Contributor: Jeff Schroeder, Kroll Security Services Group, Bastrop, Texas. MODERATE-SIZE SECURITY DESK LAYOUTS 7.666 INTE R I O R CO N ST RU CT I O N 281 A wide variety of standard console profiles are available. Different profiles can be combined into one console. Console manufacturers provide 30º and 45º wedges to fill the gaps in nonlinear console plans. SECURITY DOORS AND FRAMES Security doors provide protection from forced entry and penetration that cannot be achieved with standard wood or hollow metal doors in standard steel frames. As with any security construction, the expected level of threat must be defined before the door opening is designed and specified. This may range from simple forced opening to high explosives. SECURITY THREATS There are three general types of security threats: forced entry, penetration with tools or firearms, and destruction with explosives or other types of blasts. Low-security construction may range from heavy-gauge hollow metal doors with steel frames securely anchored in hardened partitions to sophisticated assemblies supplied by a manufacturer specializing in security doors. SECURITY GLAZING Security glazing is composed of multiple layers of glass and/or polycarbonate plastic laminated together. Depending on the degree of security protection required, thickness can range from 3/8 in. (10 mm) to approximately 2-1/2 in. (64 mm). Security glazing is subject to size limitations. LAYOUT To maximize resistance to forced entry, security doors must swing outward (toward the attack side). Walls must be constructed to meet the same level of resistance as the windows and doors installed in them. The doors must be anchored in accordance with the manufacturer’s instructions to attain the standard of resistance. CERTIFICATION AND GUIDE SPECIFICATIONS Security doors should be certified as bullet resistant by an independent testing laboratory. The Hollow Metal Manufacturers Association (HMMA), a division of the National Association of Architectural Metal Manufacturers (NAAMM), issues guide specifications for security doors and frames: • HMMA 860 : For use in building projects where traffic is relatively light and hard usage is not anticipated • HMMA 861 : For use in commercial and industrial applications where rigorous use is anticipated, such as schools, hospitals, 10_9780470889015_ch07.qxd:WILEY 9/19/11 10:34 AM 282 I N T E R IO R CO NST RU CTION industrial buildings, office buildings, hotels, nursing homes, airports, and convention centers • HMMA 862 : For use in applications where security is paramount due to a high susceptibility to vandalism, break-in, and theft, such as entrances and back doors of businesses, storerooms, warehouses, strip mall stores, apartments, and condominiums. HMMA 862 incorporates testing procedures and performance requirements promulgated by the National Institute of Justice (NIJ) for Class IV doors (ASTM F 476), including jamb/wall stiffness test, jamb/wall stiffness performance, door impact test, and door and glazing panel impact-resistance performance. • HMMA 863 : For applications in jails, prisons, detention centers, and secured areas in hospitals or courthouses. HMMA 863 requires five tests: static load test, rack test, impact load test, removable glazing stop test, and bullet resistance test. Page 282 BUILDING SERVICES TYPICAL SECURITY DOOR HARDWARE AND ACCESSORIES 7.668 WINDOW SECURITY CLASSIFICATIONS 7.669 CLASS DESCRIPTION Class I Regular glazing in commercial sash with double locks; can be wood frame Class II Heavy-duty sash with laminated glass or polycarbonate glazing; if wood, sash must be reinforced or heavy; double locks required Class III Heavy-duty sash with laminated glass over 1/4 (6 mm) thick or polycarbonate glazing 1/4 (6 mm) thick. Lock should include at least two heavy-duty dead lock bolts. Class IV Very heavy fixed frames with laminated glass over 1/4 (6 mm) thick. Security screen, bars, or shutters with special locking device SLIDING DOOR UNITS Sliding glass doors are a particular concern in securing a building. The locking devices should include vertical rod or lever bolts at top and bottom; the frame should be solid or reinforced at the locking points; the stile must also be reinforced at the locking points. The operating panels should be designed so that they cannot be lifted out of their tracks when in the locked position. Glazing and other components should be installed from the inside so that entry cannot be gained by disassembly. GLAZING DESIGN ELEMENTS Multiple glazing systems provide a greater hazard to entry/exit through broken-out windows. Reflective glazing impedes outside daytime surveillance. VAULTS CONCRETE MODULAR VAULT SYSTEMS Precast concrete modular vault panels are considerably lighter and thinner than site-poured walls, and provide almost unlimited flexibility when sizing or locating a vault. Modular vaults can be expanded or relocated as required, reusing existing components. Vault panels are typically fabricated from a high-density composite concrete mix with interlacing steel fibers and a welded grid of reinforcement bars. Although manufacturers provide standard vault sizes and configurations, a modular vault design can be custom fabricated. SLIDING GLASS DOOR 7.667 SECURITY DOOR HARDWARE The appropriate door hardware is essential for effective access control because problems frequently occur when inappropriate hardware is provided. Many lock options are available, some of which may require a specialized preparation of the door or frame; however, not all electronic hardware options are available for each door. Door hardware must first meet life safety codes for egress. FAIL-SAFE AND FAIL-SECURE HARDWARE Fail-safe door hardware is required on doors that are controlled in the direction of egress. Fail-safe door hardware unlocks on loss of power, whereas fail-secure door hardware remains locked on loss of power. Fail-secure door hardware should be used where failsafe door hardware is not required. Electric latch retraction, required on automatic doors, is not recommended. Fire-rated doors require fire-rated hardware. POSITION SWITCHES The most common type of position switch is the concealed magnetic switch. Switches should be concealed whenever possible. LOCKSETS All locksets should incorporate a dead latch pin or similar device to prevent loiding (forcing, of the door latch). Certain installations, electrified strikes in particular, may warrant the application of an astragal over the strike plate to prevent latch tampering. Contributor: Jeff Schroeder, Kroll Security Services Group, Bastrop, Texas. LOCK OPTIONS Clear spans of up to 19 ft (5.8 m) without the use of support beams can be achieved by most modular vault systems, simplifying aboveground installations. Common security door lock options include cylindrical electric, shear, and delayed-egress locks. SPECIAL SECURITY SYSTEMS • Cylindrical electric: These are less costly than mortise locksets, but not as secure as mortise locksets. • Shear: This is a type of magnetic lock concealed within a door header. It requires precise installation and more frequent adjustment than other lock types. • Delayed egress: Available in either a panic or electromagnetic variety, a delayed egress lock provides up to a 30-second delay before opening. They are not allowed in all jurisdictions. DOOR HINGES Out-swinging doors are more susceptible to tampering than inswinging doors. Nevertheless, out-swinging doors are required at many exterior locations, where protection of the hinges and latches must be considered. Exterior hinges should not have hinge pins that are easy to remove. Where possible, use concealed hinges or fix the hinge pins by welding or other means. WINDOW SECURITY A higher grade of window is required for windows hidden from public view and accessible from the ground or horizontally. This includes residential windows accessible within 12 ft (3.7 m) vertically or 6 ft (1.8) horizontally, and commercial windows accessible within 18 ft (5.5 m) vertically or 10 ft (3 m) horizontally. The use of shades and window coverings may deter intruders, depending on the ease of removal of these devices or the noise from breakage. The use of lockable shutters or roll-down blinds is very effective. BANK SECURITY Each financial institution sets the standards and defines the requirements for security, equipment, and design, depending on the location and nature of the facility. The designer must coordinate equipment installation with the design of the space. The contract documents should indicate the electrical devices that will be provided by the general contractor (such as open conduits to run wiring for CCTV and burglary wires) and power for those devices, as well as space and millwork for equipment. These items must be coordinated with the financial institution’s security equipment vendor. ROBBERY ALARM SYSTEMS Robbery alarm systems are commonly provided for banking offices at which the police can ordinarily arrive within five minutes after an alarm has been activated. Other financial institutions should be provided with appropriate devices for promptly notifying the police that a robbery has occurred or is in progress. These systems are typically activated by initiating devices located at each teller’s station or window and are safeguarded against accidental transmission. BURGLARY ALARM SYSTEMS Burglary alarm systems should be capable of promptly detecting an attack on the outer door, walls, floor, or ceiling of each vault and each safe not stored in a vault. Motion detectors are typically provided. The alarm system should signal the police, through an intermediary, indicating that a crime against the banking office has occurred or is in progress. Where police cannot arrive within five minutes, a loud bell that is audible inside and 500 ft (152 m) outside should be provided. 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 283 EQUIPMENT AND FURNISHINGS 8 EQUIPMENT The equipment included here applies across various interior applications. Refer to Chapter 9 interior Project Types for project-specific equipment. TOILET AND BATH EQUIPMENT COMMERCIAL TOILET ROOM ACCESSORIES Manufacturers supply commercial toilet room accessories for varying grades, depending on their intended use. Consult manufacturers for overall and rough-in dimensions of specific models. 2010 ADA Standards for Accessible Design requirements affecting toilet room accessories include: • Limits on objects along circulation paths protruding over 4 in. (102 mm) from the wall may affect selection and placement of equipment. • Access to controls and dispensed products should be between 15 and 48 in. (381 and 1,219 mm) above the finish floor for use by people in wheelchairs. • Hinged cover panels should not require more than 5 lb of force (22.2 N) to open. PAPER TOWEL DISPENSERS AND WASTE RECEPTACLES Paper towels may be dispensed as C-fold or multifold sheets or in rolls. Some models are designed to be convertible from sheets to rolls. Dispensers are available recessed, semirecessed, or surface mounted, and may be combined with waste receptacles. Dispensers are available in stainless steel and plastic. Waste receptacles for toilet rooms can be wall mounted or stand on the floor. Floor models are available with removable tops. Receptacles are designed to hold from 1 to 33 gal (3.8 to 125 L). Countertop-mounted circular waste chutes are designed to be used with undercounter waste receptacles. Accessibility guidelines require clearances under countertops; check applicable codes. USES CHARACTERISTICS Prestige Corporate headquarters Class A office spaces Important university and public building spaces Low to moderate traffic Minimal use and abuse High-quality materials and equipment Standard Commercial offices Healthcare facilities Hospitality Manufacturing plants Moderate to heavy traffic Some heavy use and abuse Durability and budget concerns Heavy traffic K–12 schools Retail malls Recreation projects Transportation facilities Extreme traffic flow periods Vandalism Very large capacity Durability issues HAND DRYERS 8.2 Source: Sloan Valve Company. Contributor: Charles A. Szoradi, AIA, Washington, DC. Installation recommendations for hand dryers include: • The mounting surface should be smooth and flat. • Mount 24 in. (610 mm) minimum from basins; 20 in. (508 mm) minimum from corners. • Mount multiple hand dryers 20 in. (508 mm) minimum on center. • Avoid installing hand dryers in narrow hallways and behind swinging doors. • The recommended mounting height for men is 40 in. (1,016 mm); for women, 28 in. (711 mm); and for children, 30 in. (762 mm). • The recommended accessible mounting height is 32 in. (813 mm). TOILET TISSUE DISPENSERS Toilet tissue dispensers are available recessed or surface mounted. Some models are designed to store extra rolls; others accommodate jumbo-sized rolls. Toilet tissue dispensers are designed with shelves, and with sanitary product vendors and disposal units. TOILET ROOM ACCESSORY QUALITY LEVELS 8.1 BUILDING CLASS HAND DRYERS 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 284 284 E Q U IPM E NT AND FU RNISHINGS Section 604.7 of the 2010 ADA Standards for Accessible Design requires the toilet tissue dispenser to be located between 7 and 9 in. (178 and 229 mm) in front of the water closet, measured to the centerline of the dispenser. The paper outlet must be between 15 and 48 in. (381 and 1,219 mm) above the finish floor. The 2010 ADA standards may not allow large-roll dispensers, as they must be mounted either 12 in. (305 mm) above or 1-1/2 in. (38 mm) below the side grab bar and may not fit. TOILET TISSUE DISPENSERS—RECESSED 8.3 EQUIPMENT PRODUCT DISPENSERS AND DISPOSAL UNITS BABY-CHANGING TABLES Sanitary napkin and tampon vendor units are designed for exact change or to give change; some models are convertible for various coin amounts. Models can be fully recessed or semirecessed. For accessible spaces, coin mechanism pull knobs should be operable with one hand and no more than 5 lb (2.3 kg) of force without twisting motions. They are made in plastic and stainless steel. Baby-changing tables are a great convenience to both male and female parents, and are often included in public toilet rooms, especially in unisex toilet rooms, which typically have more room for strollers. 2010 ADA Standards for Accessible Design require that baby-changing tables and other equipment do not obstruct the minimum space needed to maneuver a wheelchair into position at a water closet. Adding a baby-changing table will require exceeding the minimum space requirements for an accessible toilet space. Where provided, such convenience fixtures as baby-changing tables must be accessible to people with disabilities as well as to other users. Toilet seat cover dispensers are available both surface mounted and recessed. Facial tissue dispensers are also made to be surface mounted or recessed. They are designed to hold either 100 or 300 tissues. Soap dispensers are manufactured in a large variety of designs. The soap supply may be surface mounted, recessed into a wall, or under a countertop. Soap dispensers are available in vandal-resistant and accessible models, in stainless steel or plastic. BABY-CHANGING TABLE 8.5 Accessible soap dispensers over lavatories or countertops should be mounted no more than 42 in. (1,067 mm) above the finish floor. Push-buttons may be mounted up to 48 in. (1,219 mm) high, depending on the depth of any obstruction to wheelchair use. RECESSED SANITARY DISPOSAL UNIT 8.4 BATH AND SHOWER ACCESSORIES Bath and shower accessories made for commercial and institutional applications include: MIRRORS Commercial toilet room mirrors are available with welded or channel stainless steel frames. Unframed and minimally framed mirrors are also available. Available sizes range from 16 by 24 in. (406 by 610 mm) to 36 by 72 in. (914 by 1,829 mm). In addition to standard mirrored surfaces, polished stainless steel, tempered glass, and laminated glass surfaces are available. Tilting mirrors that extend 4 in. (102 mm) from the wall at the top and 1 in. (25 mm) at the bottom are available in widths of 16, 18, and 24 in. (406, 457, and 610 mm) and heights of 30 and 36 in. (762 and 914 mm). A full-length mirror can accommodate most people, including children and individuals using wheelchairs. 2010 ADA Standards for Accessible Design recommend that the top edge of mirrors should be 74 in. (1,880 mm) minimum from the floor to accommodate both ambulatory people and those who use wheelchairs. The Standards require mirrors above lavatories or countertops to be installed with the bottom edge of the reflecting surface 40 in. (1,016 mm) maximum above the finish floor. Those not above lavatories or countertops are to be installed with the bottom edge 35 in. (889 mm) above the floor. • Medicine cabinets: Specified with either left- or right-hand door swings. Available surface mounted or recessed. • Shower curtain rods: Heavy-duty rods are available, as are curtains and hooks. • Soap dishes: Recessed and surface-mounted soap dishes, including heavy-duty and vandal-resistant ones, are available. • Toothbrush and tumbler holders are available. • Folding seats for showers and dressing are available in phenolic resin, solid surfacing, and wood, with stainless steel, polished chrome, or other metal hardware finishes. • Hooks: Robe, clothes, utility, hat, and coat styles. Hook strips with three to four hooks and vandal-resistant hooks are also sold. Recommended mounting height is 38 to 44 in. (965 to 1,118 mm). • Stainless steel shelves: Available up to 28 ft (8.5 m) long; delivered and installed in multiple sections. 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 285 EQUIPMENT VENDING EQUIPMENT EQUIPMENT AND CLEARANCE DIMENSIONS 8.6 EQ UIPMEN T AN D F U R N I SH I N G S 285 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 286 286 E Q U IPM E NT AND FU RNISHINGS EQUIPMENT CRUTCHES 8.10 VENDING MACHINE ROOM 8.7 WHEELCHAIRS AND SCOOTERS Manual wheelchairs are hand propelled using rims mounted on large front or rear drive wheels. Armrests are usually cut away to allow closer access to tables and counters. Specialized wheelchairs are available for daily activities such as bathing and for athletic competitions such as basketball and tennis. PERSONAL CARE EQUIPMENT MOBILITY EQUIPMENT CANES Canes provide support by shifting some body weight to the user’s arm and shoulder and by helping the user to maintain balance. Long canes assist persons who are blind or visually impaired to detect obstructions in their path of travel. Long canes are typically 36 to 48 in. (914 to 1,219 mm) long; they may fold, telescope, or be rigid. Long canes may be used in either the touch technique, in which the cane is moved side to side, touching the floor surface 6 to 8 in. (152 to 203 mm) outside each shoulder, or the diagonal technique, in which the angled cane is held stationary with the tip just above the ground surface. LONG CANE 8.8 Contributor: Charles Szoradi, AIA, Washington, DC. WALKERS AND CRUTCHES Walkers can provide some support for users, but primarily they are used to help maintain balance. Folding walkers are generally made of lightweight aluminum tubing and collapse to a width of approximately 4 in. (102 mm). Basket, or rolling, walkers are 27 to 28 in. (686 to 711 mm) wide and have three or four wheels and hand brakes. Crutches reduce body weight stress on lower extremities by transferring force to either the user’s shoulders or forearms. Axillary crutches have an underarm support to transmit forces to the user’s shoulders. Nonaxillary crutches have handgrips and a forearm or upper-arm cuff to distribute weight to the user’s forearms. WALKER 8.9 Motorized wheelchairs are similar in overall size to manual wheelchairs, but they are heavier and generally less maneuverable. The frames are not collapsible, although they can be partially disassembled. Users may need assistance transferring out of their wheelchairs onto a seat, bed, or toilet fixture. Motorized wheelchairs are usually controlled by a joystick, mounted on the chair arm. The joystick restricts access to tables, desks, and other surfaces. Some motorized wheelchairs are operated by sip-and-puff controls. Individuals with impaired mobility or with stamina insufficient to travel relatively long distances may use electric scooters. Some compact scooters can turn and maneuver within parameters similar to those of wheelchairs. The scooter seat may swivel to facilitate its use in stationary positions, such as in front of a desk. Seat heights are typically adjustable to suit the rider but arms may not clear tabletops. Bariatric wheelchairs are designed for very heavy people. They have extra-wide seats and heavy-duty construction. Transport chairs, sport, lightweight, and complex, highly configured models are available as bariatric wheelchairs. Sizes vary, so check with the manufacturer to verify wheel-to-wheel and closed widths. 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 287 EQUIPMENT EQ UIPMEN T AN D F U R N I SH I N G S 287 ISLAND STYLING STATIONS 8.16 BARIATRIC WHEELCHAIRS 8.11 SEAT WIDTH WHEEL-TO-WHEEL WIDTH OVERALL WIDTH 20 (508 mm) USER WEIGHT, LB (KG) 300 (136) 27-1/2 to 30 (699 to 762 mm) 28-1/2 (724 mm) 22 (559 mm) 350 to 400 (159 to 181) 29-1/2 to 30 (749 to 762 mm) 31-3/5 (803 mm) 24 (610 mm) 400 to 600 (181 to 272) 32 (813 mm) — 26, 28, 30 (660, 711, 762 mm) 700 (318) — — MANUAL WHEELCHAIR 8.12 ELECTRIC SCOOTERS 8.14 BACKWASH SHAMPOO UNIT 8.17 MOTORIZED WHEELCHAIR 8.13 BARBER OR BEAUTY SHOP AND SPA EQUIPMENT Barber shops, beauty shops, and spas make use of a wide variety of specialized equipment. Spa and beauty shop arrangements are often a combination of enclosed and open multicustomer stations. Private treatment rooms require adequate sound insulation. BARBER AND BEAUTY SHOP EQUIPMENT To estimate the total area for a beauty shop, including reception, styling and drying areas, shampoo room, and restrooms, allow approximately 200 sq ft (18.6 sq m) per stylist. Beauty shops often incorporate manicure and pedicure stations. The accompanying figures focus on equipment layout dimensions and clearances; equipment particulars vary by manufacturer. WALL STYLING STATIONS 8.15 Contributors: Kim A. Beasley, AIA, and Thomas D. Davies Jr., AIA, Paralyzed Veterans of America Architecture, Washington, DC. Salon Equipment International Inc., Bellflower, California. CONVENTIONAL SHAMPOO STATION 8.18 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 288 288 E Q U IPM E NT AND FU RNISHINGS PEDICURE STATIONS 8.19 EQUIPMENT LAUNDRY FACILITIES Laundry facilities are categorized as community laundry rooms, launderettes, or on-site (on-premise) commercial facilities. In all commercial laundry rooms, include a floor or trench drain underneath or behind the washers to handle washing machine overflow and sized to contain one complete cycle from all of the machines. To maximize the space efficiency, utilize stackable dryers. ACCESSIBILITY SPA EQUIPMENT Spa facilities often include a range of services other than beauty shop treatments, including massage, hydrotherapy, skin care or facial rooms, exercise facilities, and yoga and meditation spaces. Rooms for yoga and meditation require storage for yoga mats, balls, and mediation cushions. A minimum of 10% of the room area should be allocated for equipment storage. Temperature and lighting conditions for various uses may require flexible design and control solutions. Wet and dry treatment rooms require a treatment table, sink, lockable storage, a counter with a mirror, and clothing hooks. Wet treatment rooms require a floor drain, overhead shower or treatment shower, and an infrared heat lamp recessed into the ceiling above the treatment table. HYDROTHERAPY OR MASSAGE ROOM 8.20 Commercial laundries must be accessible to persons with disabilities. The 2010 ADA Standards for Accessible Design require 1 or 2 accessible machines, depending on the total number. If front-loading machines are provided, the bottom of the laundry compartment must be 15 to 24 in. (381 to 610 mm) maximum above the floor. For toploading machines, the compartment must be 36 in. (914 mm) maximum above the floor. A clear floor area 30 by 48 in. (762 by 1,219 mm) centered on the machine must be provided for a parallel approach, and operable parts must be within reach range. The 2010 ADA Standards include an exemption that permits a maximum height 2 in. (51 mm) above the limit for high reach over an obstruction. COMMUNITY LAUNDRY ROOMS In community laundry rooms such as in college dormitories or apartment complexes, washing machines are generally residential size and operated by coin or debit card. Consider the residential profile when determining the equipment needs: • For families, plan one washer and dryer for every 8 to 12 units. • Young working adults require one washer and dryer for every 10 to 15 units. • Older working adults need one washer and dryer for every 15 to 20 units. • Students or senior citizens require one washer and dryer for every 25 to 40 units. LAUNDERETTES A launderette is a commercial self-service laundry with coin-operated equipment. For launderettes, plan a mix of single-, double-, and triple-load washing machines; determine the size of dryer/tumblers by considering the neighborhood and clientele expected. ON-PREMISE LAUNDRY FACILITIES To plan on-premise laundry facilities for beauty salons, healthcare facilities, health clubs, hotels, or restaurants, estimate the approximate pounds of laundry use per day. The estimates will vary by facility type based on the types of services offered and the weights of the uniforms, towels, and linens. Variables for hotels include type of hotel, number of rooms, and hotel occupancy. Estimate 8 lb (3.6 kg) per room per day for a budget motel, 10 lb (4.6 kg) per room per day for a midrange suite/hotel, and 12 lb (5.4 kg) per room per day for a resort or luxury hotel. Consider reductions to volumes in facilities that implement water conservation programs. DRYER/TUMBLER SIZES 8.22 CAPACITY, LB (KG) WIDTH DEPTH 30 to 35 (13.6 to 15.9) 28 to 31-1/2 (711 to 800 mm) 39 to 45 (991 to 1,143 mm) 50 (22.7) 34 to 39 (864 to 991 mm) 47 to 50 (1,194 to 1,270 mm) 75 (34) 39 to 51-1/2 (991 to 1,308 mm) 53 to 87-1/2 (1,346 to 2,223 mm) 100 to 125 (45 to 56.7) 46 to 48 (1,168 to 1,219 mm) 65 to 87-1/2 (1,651 to 2,223 mm) 150 to 200 (68 to 91) 53 to 55 (1,346 to 1,397 mm) 62 to 96-1/2 (1,575 to 2,451 mm) WASHER/EXTRACTOR SIZES 8.23 CAPACITY, LB (KG) WIDTH DEPTH 50 to 60 (22.7 to 27.2) 30 to 38-3/4 (762 to 984 mm) 42-1/2 to 45 (1,080 to 1,143 mm) 80 (36.3) 41-1/2 to 51 (1,054 to 1,295 mm) 41 to 51-1/2 (1,041 to 1,308 mm) 100 (45) 41-1/2 to 56-1/2 (1,054 to 1,435 mm) 48-1/2 to 54-1/2 (1,232 to 1,385 mm) 125 (56.7) 47 to 52 (1,194 to 1,321 mm) 58 to 61-1/4 (1,473 to 1,556 mm) 140 (63.5) 59 to 62 (1,499 to 1,575 mm) 56 to 59 (1,422 to 1,499 mm) LAUNDRY EQUIPMENT GUIDE FOR HOTELS, MOTELS, AND RESORTS 8.24 SKIN CARE OR FACIAL ROOM 8.21 NUMBER OF ROOMS EQUIPMENT TYPE 25 to 50 Washer/extractor 1 at 35 lb (16 kg) Dryer 1 at 50 lb (23 kg) Washer/extractor 2 at 35 lb (16 kg) Dryer 2 at 50 lb (23 kg) or 2 at 75 lb (34 kg) Washer/extractor 2 at 35 lb (16 kg) and 1 at 50 lb (23 kg) Dryer 3 at 50 lb (23 kg) or 2 at 75 lb (34 kg) Washer/extractor 2 at 50 lb (23 kg) Dryer 3 at 75 lb (34 kg) 51 to 80 81 to 120 121 to 150 NOTE 8.24 Average two doubles per room at 80% occupancy. Contributors: Duane Fisher, Richard Newton Associates, Washington, DC. Maytag Corporation, Newton, Iowa. Multi-housing Laundry Association (MLA), Raleigh, North Carolina. EQUIPMENT QUANTITY AT SIZE SPACE REQUIRED 12-0 12-0 (3.7 3.7 m) 12-0 13-0 (3.7 4 m) 12-0 15-0 (3.7 4.6 m) 15-0 15-0 (4.6 4.6 m) 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 289 EQUIPMENT TYPICAL PLANS FOR LAUNDRY ROOMS 8.25 FRONT-LOADING LAUNDRY EQUIPMENT 8.26 Contributors: Duane Fisher, Richard Newton Associates, Washington, DC. Maytag Corporation, Newton, Iowa. Multi-housing Laundry Association (MLA), Raleigh, North Carolina. EQ UIPMEN T AN D F U R N I SH I N G S 289 11_9780470889015_ch08.qxd:WILEY 9/19/11 10:42 AM Page 290 290 E Q U IPM E NT AND FU RNISHINGS TELLER AND SERVICE EQUIPMENT Teller and service equipment includes a wide range of transaction equipment for the handling and transfer of money and other highsecurity items, including built-in and freestanding ticket windows, package transfer units, and automated teller machines. There is a wide range of specialized equipment in this category beyond what is contained here. FABRICATED TICKET AND CASHIER WINDOW 8.27 EQUIPMENT TRANSACTION EQUIPMENT Tellers, cashiers, and other transaction personnel should be effectively protected by ballistics-resi

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