DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DIVISION 7
THERMAL AND
MOISTURE PROTECTION
Division 7 of the Carnegie Mellon University Design and Construction Standards Manual
addresses the following thermal and moisture protection standards related to University
projects.
07100
07180
07200
07265
07270
07500
07570
07620
07720
07820
07900
WATERPROOFING AND DAMPPROOFING
WATER REPELLENT COATINGS
INSULATION AND VAPOR BARRIERS
FIREPROOFING
FIRESTOPPING
ROOFING SYSTEMS
TRAFFIC COATINGS
FLASHING AND SHEET METAL
ROOF ACCESSORIES
SKYLIGHTS
SEALANTS
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
07100 WATERPROOFING AND DAMPPROOFING
Waterproofing is intended to create a barrier that large quantities of water under pressure
(such as standing water) cannot penetrate. Dampproofing is intended to prevent the
penetration of small quantities of water not under pressure; it is often used to control
dampness and water vapor. As waterproofing is a more rigorous and usually a more
expensive treatment than dampproofing, waterproofing should only be used when
dampproofing will not provide sufficient protection.
Waterproofing
Below-Grade Waterproofing
To waterproof a below-grade structure, all below-grade horizontal and vertical surfaces
must be covered with the waterproofing substance. This can, however, subject the
structure to upward hydrostatic forces (similar to the forces of water on a boat). The
structure may need to be designed to resist “floating” and the horizontal slabs may need
to be designed to resist upward hydrostatic pressure. Waterproofing the vertical and
horizontal surfaces requires careful detailing of joints and intersections.
Terraces and Above-Occupied Spaces
Although terraces and above-occupied spaces are similar to roofs in function, they are not
typically covered by roof warranties. (For one reason, they are traffic bearing.) In this
application, the top of the waterproofing layer should slope to drain and should not pond
water. Elastomeric liquid-applied membranes and sheet-applied membranes can often be
used successfully. Fully-adhered systems have the advantage of localizing leaks.
Membrane Waterproofing
The installation of a membrane waterproofing material is required at all suspended
interior floor areas where rest rooms, toilets, showers, and similar water-use facilities are
located.
Rubberized Asphalt Sheet Waterproofing
The Design Consultant is responsible for selecting a waterproofing system to solve a
specific situation. Where suitable, the University prefers to specify rubberized asphalt
sheet waterproofing or bituthene manufactured by W. R. Grace and Company. This
product should not be exposed to ultraviolet light.
The self-adhering membrane of rubberized asphalt integrally bonded to polyethylene
sheeting (thickness not less than 56 mil), shall comply with the following:
Tensile Strength:
ASTM D 412, 250 psi minimum
Ultimate Elongation:
ASTM D 412, 300% minimum
Pliability Temperature:
ASTM D 146, -25 °F
Hydrostatic Head Resistance: 150 ft minimum
Water Absolution:
ASTM D 570, not more than 0.5% weight gain after
48 hours of immersion at 70 °F
December 1998
P. 7-3
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Field Testing
Since waterproofing is intended to stop large quantities of water under pressure and is
often used where water damage would be a significant problem, it is strongly
recommended that field tests of waterproofing be conducted after it is installed and before
it is covered. Field tests of waterproofing are often very simple; ponding tests and water
spray tests are the most common forms. The Contractor should ensure that the structure
can withstand the load before making ponding tests.
Waterproofing Warranty
The Contractor shall provide a 10-year warranty for waterproofing systems and adjacent
work disturbed during repairs and/or replacement.
Dampproofing
Dampproofing should not be used if an area will at any time be subjected to hydrostatic
water pressure of 62 lb/ft.
Dampproofing Below Grade
Below-grade dampproofing (which includes but is not limited to foundation walls and all
masonry work) shall be accomplished with either water-based emulsions or Volclay
products. Solvent products can be used in lower ambient temperatures, but sometimes
cannot be applied over newly installed concrete until the concrete has cured. Water-based
emulsions can freeze and often require higher working temperatures. Emulsion
dampproofing can usually be applied over concrete immediately after the forms are
stripped.
Exterior Wall Cavities
Volclay panels installed under pressure, bituthene, and emulsion dampproofing are the
best products for application on exterior wall cavities. Solvent products can sometimes
leach oils that stain other materials, usually near weep holes. Asphalt-impregnated
building paper felt can also be used as dampproofing.
Other Requirements
All products shall comply with strict VOC and MSDS requirements.
07180 WATER REPELLENT COATINGS
Water repellent coatings are transparent liquid applications for masonry, stone, and
concrete.
Materials
The University prefers two types of water repellent coatings: silicone and acrylic.
P. 7-4
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
Each product has advantages and disadvantages that should be considered for a specific
application to minimize altering the surface to which it is applied as well as adjoining
materials.
Horizontal Concrete Surfaces
Water repellent coatings are often used on horizontal concrete surfaces to reduce water
and salt (chloride ion) penetration.
Brick Masonry
Water repellents should be avoided on brick masonry since the water repellent can affect
vapor migration and possibly trap moisture causing spalling and freeze/thaw problems.
Exterior Concrete Masonry
Some type of water repellent coating is often needed on single wythe exterior concrete
masonry walls to make the walls watertight. An elastomeric breathable masonry paint
also should be considered.
Testing
Before proceeding with installation, the Contractor should perform a field test by
applying the selected water repellent to mock-up or small test areas, subject to
compliance with the manufacturer’s requirements and recommendations for each
substrate.
Since water repellent coating is intended to reduce damage and corrosion of reinforcing
steel, tests may be appropriate for critical applications. Concrete cores can be taken prior
to material application to provide a baseline record. Additional cores can be taken after
material is applied. If a problem occurs in the future, cores can be taken and compared to
the original cores to see if the material performed as promised and if the installation was
accomplished correctly.
07200 INSULATION AND VAPOR BARRIERS
Insulation
The University has adopted the following guidelines for insulation.
Minimum Levels of Performance
Non-Window Above-Grade
Vertical Enclosures:
Windows:
Roof Assembly:
December 1998
U-value of 0.080 Btu/hr/ft2/°F or better
U-value of between 0.52 and 0.68 Btu/hr/ft2/°F
U-value of 0.050 Btu/hr/ft2/°F or better
P. 7-5
DIVISION 7
DESIGN AND CONSTRUCTION STANDARDS
THERMAL AND MOISTURE PROTECTION
FACILITIES MANAGEMENT SERVICES
Cost Effectiveness of Higher Energy Performance
A building life-cycle analysis shall be made to determine if higher energy performance is
cost effective. To exceed the minimum requirements, the Contractor should review
Pennsylvania Act 222 where required.
Fire Performance
The Contractor shall provide insulation materials identical to those whose indicated fire
performance characteristics have been determined (per the ASTM test method indicated
below) by Underwriters Laboratories (UL) or other testing and inspecting organizations
acceptable to authorities having jurisdiction.
Surface Burning Characteristic: ASTM E 84
Fire Resistance Ratings:
ASTM E 119
Combustion Characteristics:
ASTM E 136
Formaldehyde Foam Insulation
Formaldehyde foam insulation is not permitted on University projects.
Environmental Considerations
The Contractor should be especially careful to insulate steam tunnels and pipes beneath
plants and trees. The heat can interfere with the normal winter dormant cycles of the
plants and trees, causing damage or death.
Vapor Barriers
Vapor barriers are needed to control the movement of water vapor and to prevent
condensation within exterior building assemblies. Vapor barriers may be needed in walls
and roofs. (Roof vapor barriers should be specified in the Roof Specification.)
Several types of vapor barriers may be used:
• Separate vapor barriers such as polyethylene sheeting
• Vapor barrier facings on the insulation
• Foil-faced type “x” gypsum wallboard
Whichever type is used, the vapor barrier must be continuous and undamaged to function
properly. Seams and penetrations for utilities are critical areas.
07265 FIREPROOFING
The extent and performance of fireproofing is basically defined in building codes.
However, it is not sufficient on University projects to simply require contractors to “meet
code.” The Design Consultant should clearly indicate in Contract documents:
• The scope of fireproofing work
• The fire-resistance ratings required
• The limits of each type of fireproofing when more than one type is used
P. 7-6
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
Fireproofing must be UL or Factory Mutual (FM) approved. If UL approved, it should
match UL tested and listed assemblies. Contract documents should note the UL
assemblies to be matched.
Fireproofing Materials
Sprayed mineral fiber, cementitious, and intumescent mastic fireproofing materials are
commonly used. The preferred system is Monokote manufactured by W. R. Grace and
Company. The preferred mineral fiberboard fireproofing is manufactured by Celotex
Corporation.
Field Tests
Installed fireproofing should be tested for density, thickness, bond, and other important
characteristics. Since the application technique can result in significant variation in these
characteristics, and since fireproofing that is not up to specification may not perform as
intended, field tests are important and should be required for most projects.
The Contract documents should state that the University will provide and pay for all
testing, unless specifically indicated otherwise.
Friability
Some types of fireproofing (especially low-density, low-bond-strength types such as
mineral fiber) have problems with friability when used in areas of high air movement
such as plenums and in areas of vibration such as steel supporting elevators or machinery.
Non-friable fireproofing should be selected to mitigate these problems.
Mold and Mildew Inhibitors
Some types of fireproofing provide an excellent base for mold, mildew, and other
unwanted growth. This can be a major problem in medical, laboratory, and research
spaces. These problems should be anticipated and corrective mold and mildewcide
admixtures should be specified in the original application.
Visible Applications
Where fireproofing is visible, architectural finishes may be used to conceal the
fireproofing or the fireproofing itself may be treated with plaster-like coatings to create
acceptable exposed surfaces. In areas subject to contact and abuse, special fireproofing
suitable for this exposure is required. Intumescent mastic fireproofing is often used where
hard, durable, and architecturally pleasing fireproofing is needed.
Asbestos
No asbestos-containing products are permitted on University projects.
December 1998
P. 7-7
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
07270 FIRESTOPPING
The University requirements are those set forth in the BOCA building code, which
describes the extent and intent of firestopping work.
Applications
The type of fireproofing selected should accommodate the expected use. For example,
building areas with cable runs require a specific firestopping system. Since several
locations will typically need to be firestopped, several firestopping materials and systems
will be used.
Required Submittals
Each of the firestopping systems to be used should match a UL or FM listed and tested
firestopping assembly. The Contract documents should require detailed submittals and
information on similar UL or FM listed assemblies for each type of firestopping system
used.
Single-Source Responsibility
A single-source responsibility should be required for firestopping systems for each kind
of penetration and condition. Material and installation procedures should be obtained
from a single-source manufacturer.
The preferred sealant manufacturers are:
• Dow Corning Fire Sealant
• 3M Company Fire Barrier
Procedures
Strict review and inspection procedures shall be written into project specifications to help
ensure that firestopping work is done properly. Contractors should obtain the approval of
the University Project Manager prior to enclosing and concealing firestopping work.
Wall, Floor, and Ceiling Penetrations
All wall and floor penetrations containing conduit, piping, telecommunications cables,
ductwork, and the like that pass through fire-rated masonry construction shall be sealed
with an approved fire-rated mortar seal. Mortar seal thickness shall equal or exceed the
designated fire rating. KBS mortar seal is an approved fire protection system. Other wall,
floor, and ceiling penetrations passing through material with fire-rated assemblies shall be
firestopped with approved fire-rated materials that maintain or exceed the fire-rated
and/or smoke-rated assembly.
07500 ROOFING SYSTEMS
The University employs a three-pronged strategy to ensure adequate performance of roof
systems: proper design, suitable material selection, and rigid inspection.
P. 7-8
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
Design
The Design Consultant shall review roofing systems with the University during the design
phase of a project.
Particular attention to the design of plazas and other accessible roof areas is mandatory.
These areas are expensive to maintain and they must be adequately detailed and specified
to ensure a quality installation.
Careful attention shall also be given to parapet details to avoid affecting the building’s
appearance. Proposed parapet modifications require prior approval of the University
Project Manager.
All roofing on or adjacent to historical buildings requires prior approval of the University
Project Manager.
Roof Materials
The types of roofing systems to be used on University projects and their performance
requirements are as follows:
Systems/Materials
The following roofing systems shall be used on University projects:
• Four-ply built-up tar and gravel roofing systems
• Two-ply styrene-butadiene-styrene (SBS)-modified Bitumen roofing systems
• Single-ply membrane roofing such as fully-adhered and mechanically-fastened
ethylene propylene diene monomer (EPDM), polyvinyl chloride (PVC), and Hypalon
roofing systems (ballasted roofs are not permitted.)
• Mechanically-fastened roof assemblies, which have the advantage of reducing the
quantity of combustible material in the roof system
• Standing-seam metal roof systems
• Inverted-roof membrane assemblies (These can be applied to all other roofing
systems.)
Performance
The following minimal levels of roof performance shall be provided:
Wind Uplift:
FM Class I-90
External Fire Performance:
UL Class A
Internal Fire Performance:
Roof ceiling assembly to comply with all building
codes and UL assembly ratings
All appropriate ASTM standards for the various roof systems shall apply.
Roof Insulation
The University has adopted the following requirements for roof insulation.
December 1998
P. 7-9
DIVISION 7
DESIGN AND CONSTRUCTION STANDARDS
THERMAL AND MOISTURE PROTECTION
FACILITIES MANAGEMENT SERVICES
Fire Resistance
Fire-resistive or fire-retardant roof insulation is required.
Tapered Insulation
Where possible, structural decks should be sloped to drain, minimizing the quantity of
tapered insulation needed.
Performance Requirements
Roof insulation should be used that meets the performance requirements listed in Section
07200 Insulation and Vapor Barriers and that provides at least the insulating value
required by building codes and Pennsylvania Act 222.
When polyisocyanurate insulation is used, a maximum aged R-Value of 5.6 per in.
thickness is required. This value is lower than the values typically published by insulation
manufacturers. This lower value is recommended by the National Roofing Contractors
Association. Polyisocyanurate insulation may not comply with the following
requirements:
Environmental Protection—The Contractor shall not use or specify any roof insulation
that is produced with CFC (chloroflurocarbon) blowing agents, which can damage the
Earth’s ozone layer.
Recyclability—The Contractor shall consider the potential for recyclability when
choosing roof insulation for any application where the roof insulation may need to be
discarded in the future.
Installation
Pre-Installation Meeting
The Design Consultant shall specify that a meeting of all involved parties be held prior to
commencement of the work.
Manufacturer’s Recommendations
All roofing, insulation, and accessories shall be provided and installed in strict
accordance with the manufacturer’s recommendations.
Asbestos Considerations
Many old roofing felts contain asbestos. Samples of existing roofs shall be tested for the
presence of asbestos before roof removal. Disposal of existing roofing is often treated as
hazardous and requires special removal, transportation, and disposal procedures, which
should be specified. For these reasons, leaving an existing roof in place and re-roofing
over the top should be considered.
Roofing Over An Existing Installation
The Contractor should never re-roof over existing wet insulation and damaged roof
decking. The existing ballast and gravel shall be removed before re-roofing. Special
efforts shall be made to control dust. Even if new insulation is not required, the
P. 7-10
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
Contractor shall provide at least a thin isolation layer of insulation between old and new
roof assemblies. The Contractor shall require the roof manufacturer’s representative to
inspect and accept in writing all existing roof substrates prior to installation of new
roofing; this is to prevent a claim of substrate unsuitability at a later date. Furthermore,
the Contractor shall be required to flush and clean all roof drains before beginning reroofing work and to verify that the drains are clean after completion of re-roofing work.
Construction Traffic
The Contractor shall be required to control and restrict construction traffic over a new
roofing system. Where traffic or work is unavoidable, effective temporary protection is
required to prevent roof damage and wear. The use of oils, chemicals, solvents, and other
materials known to be damaging to new roofing systems are prohibited. (The list of
prohibitions can be obtained from the roof manufacturer.)
The Contractor shall provide walking pads leading to all rooftop equipment, exitways,
and penthouses.
Test and Inspection
Testing and infrared scanning shall be performed prior to re-roofing work. Test-cuts to
inspect insulation and infrared-scanning to check for excessive heat loss and to identify
areas where insulation is not performing properly shall be performed by an independent
testing agency and shall be the responsibility of the University.
Warranty
The Contractor shall be required to provide a 15-year minimum warranty covering all
labor and material to repair or replace roofing as needed to eliminate leakage and to meet
the performance criteria. Roof bonds shall become the property of the University.
07570 TRAFFIC COATINGS
Traffic coating systems are waterproof traffic-bearing elastomeric membranes. These are
commonly used in parking garages over occupied spaces and on balconies and terraces.
Manufacturers of these products typically offer different grades of product to suit the
intended traffic—both pedestrian and vehicular.
Requirements
The physical requirements of traffic coatings shall comply with ASTM C 957.
Materials identical to those of traffic coatings tested in accordance with ASTM E 108 for
deck type and slopes indicated for the following class of exterior fire test exposure shall
be used:
• Class A
• Class B
• Class C
December 1998
P. 7-11
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
As the recommended thickness of each coat in a standard traffic coating system varies
with the manufacturer, coatings shall be applied in strict compliance with the
manufacturer’s recommendations and ASTM C 1193.
Surfaces to receive traffic coatings must be reviewed for compatibility and accepted by
the traffic-coating manufacturer before the system is installed. This is especially
important for surfaces that may be contaminated with oil or other substances and for
surfaces with previously applied coating systems.
Traffic coating systems must be highly resistant to winter de-icing chemicals and should
be slip-resistant in compliance with ADA guidelines.
All solvents must be in strict accordance with VOC and MSDS requirements.
Single-Source Responsibility
Sealants are usually an important part of a traffic coating system. All work related to
traffic coating systems, including surface preparation and sealants, should be assigned to
only one manufacturer and installer.
Warranty
The Contractor shall provide a minimum five-year warranty for material and installation
as well as repair of adjacent improvements.
07620 FLASHING AND SHEET METAL
Flashing and sheet metal work shall comply with Architectural Sheet Metal Manual of the
Sheet Metal and Air Conditioning Contractors National Association (SMACNA).
Specific metals such as copper should also comply with specific trade standards such as
publications of the Copper Development Association and the National Roof Contractors
Association.
Minimum Guidelines For Metal Thickness
The minimum ASTM recommendations for metal thickness are as follows:
Copper—ASTM B 370; temper H00 (cold rolled); 20 oz when not fully supported.
Lead-Coated Copper—16 and 20 oz copper as stated above with minimum 1.92-oz lead
coating (total weight of lead on both sides). SMACNA recommends 3.2 oz of lead
coating in industrial applications and polluted urban environments; this recommendation
would likely apply to work immediately adjacent to chimneys, flues, fume hood exhausts,
and other localized polluted environments.
Sheet Aluminum—ASTM B 209; alloy 3003, temper H14. For highly visible work such
as fascias, 0.050 in. is minimum with 0.063 in. preferred. For concealed work, 0.040 in. is
minimum with 0.050 in. preferred. Since aluminum cannot be soldered, other methods of
seaming and jointing shall be considered. Joints shall be specified and detailed that are
visually acceptable and offer long-term protection against weather.
P. 7-12
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
Sheet Lead—ASTM B 749; type L51121, minimum 4 lb/ft2 (0.0625-in. thick).
Flexible Sheet Membrane—60 mil in thickness complying with the following:
Shore A Hardness:
ASTM D 2240, 50 to 70
Tensile Strength:
ASTM D 412, 1200 psi
Tear Resistance:
ASTM D 624 Die C, 20 lb per linear in.
Ultimate Elongation:
ASTM D 412, 250%
Low Temperature Brittleness:
ASTM D 746, -30 °F
Resistance to Ozone Aging:
ASTM D 1149
Resistance to Heat Aging:
ASTM D 573
Membrane Flashings
Acceptable membrane flashings include:
• Permabarrier manufactured by W. R. Grace and Company
• Polyvinyl chloride flashings, minimum 30 mil thickness
• Metal flashings
The Contractor shall not use membrane flashings where the flashing is not fully
supported, where the flashing will be exposed to sunlight, or where the flashing will be
incompatible with sealants.
Laminated Flashings
The University does not accept the use of laminated flashings such as copper-paper.
Galvanized Steel Flashings
The University prefers to avoid galvanized steel flashings because of problems with
corrosion and painting.
Painted Finishes
Clear anodized and color anodized finishes shall be Class 1 (at least 0.7 mil thick). Some
manufacturers offer Class 2 (0.4 mil thick), which is generally accepted for interior work
only. Kynar 500TM-based paint is the best choice for painted finishes. Baked enamel paint
finishes are cheaper, but should be avoided since there are problems with long-term color
retention and paint film performance.
Expansion Joints
The Contractor shall show spacing, locations, and details of expansion joints in sheet
metal work. Failure to control expansion often results in flashing failures such as flashing
pulling out from reglets.
December 1998
P. 7-13
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Scuppers
In locations where parapet walls contain a standard roof drain system as a back up to
prevent overflow, scuppers are required.
07720 ROOF ACCESSORIES
For access to roofs, the University prefers the use of stairs with doors rather than roof
access hatches. This is because it is more difficult, and less safe, for maintenance
personnel to use the ladders and ship-stairs associated with access hatches.
Roof Access Hatches
Where roof access hatches are unavoidable, they should have the following features:
• Insulated metal lids
• A minimum size of 3 ft x 2.5 ft, larger if possible
• Equipped with a padlock eye on the interior to restrict access to the roof unless access
to the roof hatch is in a locked, secured room
In general, access hatches should not be locked from the outside. Free entrance to the
building from the roof is desired, except when the roof height or other conditions indicate
that this would cause problems with unauthorized entrance.
Alarm Protection
Roof access hatches may require security alarm protection. The Design Consultant should
verify with the University Project Manager when an alarm is required.
Heat and Smoke Vents
These should be installed as required to comply with codes and to vent products of
combustion to the exterior. Heat and smoke vents must be easily opened from the exterior
to permit firefighters to open the vents from the roof.
Testing Heat and Smoke Vents
After installation and before acceptance by the University, each heat and smoke vent must
be field tested to ensure that it will properly open automatically. After testing, all melted
fusible links and other damage shall be replaced or restored to “ready” status.
Roof Equipment Curbs
These are sometimes specified with the equipment and sometimes specified separately.
The Contractor shall coordinate with the Design Consultant to ensure that equipment
curbs are adequately addressed in only one section of the Contract documents.
In general, metal curbs with insulated bases are preferred, but the actual selection must be
coordinated with the equipment to be supported. The roofing and flashing details of the
P. 7-14
December 1998
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
DIVISION 7
THERMAL AND MOISTURE PROTECTION
curb should be reviewed prior to selection to ensure that a simple, easy to maintain and
repair condition is created.
Pitch Pockets
The University does not permit pitch pockets without a review of specific details by the
University Project Manager.
Snow Management Systems
The Design Consultant shall provide the means to prevent the fall of snow from roofs at
entranceways and along walkways.
07820 SKYLIGHTS
The Contractor shall require single-source responsibility for skylights, including the
entire skylight assembly, all sealants, and glass and glazing.
Standards
Skylight design and construction shall comply with the following standards:
• ASTM D 1003-61
• ASTM D 1044-85
• ASTM E 84-84
• AAMA 1502.7
• AAMA 1600-1986
• AAMA 1603-1980
• AAMA 1605-198
Skylight Performance
The entire skylight assembly should be engineered by the skylight manufacturer to safely
support all loads required by codes. If special loads are required, such as loads due to
special skylight cleaning techniques, these should be specified.
Air and Water Infiltration
Air infiltration shall be limited to a maximum of 0.10 cfm per square foot of skylight area
when tested at not less than 6.75 lb/ft2 pressure difference. Under test conditions, there
should be no water infiltration at not less than 9 lb/ft2 pressure difference. In practice, no
uncontrolled water infiltration of any quantity at any time is acceptable. Water that is
collected and wept to the exterior is generally acceptable.
Condensation Control
Leaks in skylights are sometimes caused by uncontrolled condensation forming on the
interior of the skylight assembly. Each skylight system should include interior gutters to
December 1998
P. 7-15
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
collect and conduct condensation to the exterior through weeps. Soldered joints in interior
gutters sometimes leak and should be avoided. Steeply pitched skylights encourage
condensation to run to the gutters instead of dripping. Framing for the skylight should
have a Condensation Resistance Factor (CRF) of at least 52, per AAMA 1502.7. Low
interior humidity will help control condensation. The Contractor should discuss this with
the Design Consultant.
Painting Finishes
Clear anodized and color anodized finishes should be Class 1 (at least 0.7 mil thick).
Some manufacturers offer Class 2 (0.4 mil thick), which is generally accepted for interior
work only. Kynar 500TM based paint is the best choice for painted finishes. Baked enamel
paint finishes are cheaper, but should be avoided since there are problems with long-term
color retention and paint film performance.
Glass
Insulated glass units should be used over air-conditioned space. For the exterior pane,
glass that is strong in bending (like tempered glass) is often used. The exterior pane is
often tinted or coated to control heat gain. The inner pane must be laminated safety glass.
Tempered glass is not acceptable in this location since it would easily fall from the
skylight when broken (laminated glass is more likely to stay broken within the frame).
Wire glass is not safety glass and cannot be used in any skylight. When replacing old wire
glass in an old skylight, the glass indicated above shall be used and not wire glass.
Sealants
Silicone sealants are often used in skylights. Structural silicone glazing is commonly used
at horizontal glazing joints where an exterior bar or cap strip would obstruct the flow of
water or snow. Vertical joints often have compression glazing gaskets with bolted-on
compression plates; the compression plates are often covered with a decorative snap-on
cover.
Plastic Dome Skylights
If individual plastic dome skylights are ganged together into a large skylight assembly,
the entire assembly must slope to drain to prevent water from standing between the
skylight modules.
Installation
Installation shall comply with the manufacturer’s instructions and recommendations.
The Contractor shall coordinate skylight installation with the installation of the roof deck
and other substrates to ensure that each element of the work (i.e., accessory units, vapor
barriers, roof insulation, roofing, and flashing) performs properly, and that combined
elements are waterproof and weathertight. Skylight units shall be securely anchored to
supporting structural substrates to adequately withstand lateral and thermal stresses as
well as inward and outward loading pressures.
P. 7-16
December 1998
DESIGN AND CONSTRUCTION STANDARDS
DIVISION 7
FACILITIES MANAGEMENT SERVICES
THERMAL AND MOISTURE PROTECTION
Warranty
The Contractor shall provide a minimum 10-year warranty for all skylight assemblies.
The warranty shall cover repairs—including materials and installation as well as
reconstruction or repairs to adjacent surfaces.
07900 SEALANTS
The University prefers the following types of sealants for the applications listed below.
Sealant Applications
Application
Sealant Type
Typical vertical exterior building joints
Non-sag, multi-part polyurethane, or silicone
Typical horizontal exterior building joints
Self-leveling, multi-part polyurethane
Typical interior joints at toilet rooms, plumbing
fixtures, and wet areas
Mildew-resistant silicone
Typical interior sealant
Acrylic latex
Concealed acoustical sealant
Acoustical sealant
Glazing sealant
See Section 08800 Glazing
Sealant Location
The following locations, which often require the use of sealant, should be clearly
documented in Contract documents:
• The top of the wall base at irregular walls and rough substrates like masonry
• The perimeter of an interior door, sidelight, and borrowlight frames
• At the joint between acoustical ceiling wall angles and irregular walls
• At countertops
• At inside (concave) corners in ceramic tile wall finishes
Colors
For building exteriors, the Contractor should choose sealant colors that are known to be
stable and durable. Sealant colors are often unstable and can dramatically change the look
of a building when they bleach white. The Contractor should require proof of the color
stability or a very tight warranty.
Testing
Sealant manufacturers typically recommend project-specific tests to ensure that the
correct primer and sealant is used. Laboratory tests using samples of window finishes and
field tests for adhesion are highly recommended. Sealant manufacturers’ catalogs often
include information on testing.
December 1998
P. 7-17
DIVISION 7
THERMAL AND MOISTURE PROTECTION
DESIGN AND CONSTRUCTION STANDARDS
FACILITIES MANAGEMENT SERVICES
Movement
Sealant has limited movement capability. Each type of sealant has a different movement
capability, with the best sealants offering only 50% movement under ideal conditions.
The Contractor should check the movement capability when selecting a sealant and when
designing the joint width. Since each joint may accommodate only a small movement,
several joints or unusually wide joints may be needed.
Flammability
Sealers and fillers shall be non-flammable or have a flash point not less than 175 °F.
Installation
All sealants shall be installed in accordance with the manufacturer’s instructions as well
as all ASTM standards that apply.
Experience
The installer is required to have successfully completed within the last three years at least
three joint sealer applications similar in type and size to that required by the project.
P. 7-18
December 1998