Color profile: Generic CMYK printer profile
Composite Default screen
ACCESSIBILITY
TABLE 1109.12.2
ACCESSIBLE CHECK-OUT AISLES
MINIMUM NUMBER OF ACCESSIBLE
CHECK-OUT AISLES OF EACH
FUNCTION
1 to 4
1
5 to 8
2
9 to 15
3
Over 15
3, plus 20% of additional aisles
1109.12.3 Point of sale and service counters. Where counters are provided for sales or distribution of goods or services, at least one of each type provided shall be accessible.
Where such counters are dispersed throughout the building
or facility, accessible counters shall also be dispersed.
Exception: Accessible windows are not required in
bathrooms or kitchens.
1109.14 Recreational and sports facilities. Recreational and
sports facilities shall be provided with accessible features in
accordance with Sections 1109.14.1 through 1109.14.4.
1109.14.1 Facilities serving a single building. In Group
R-2 and R-3 occupancies where recreational facilities are
provided serving a single building containing Type A units
or Type B units, 25 percent, but not less than one, of each
type of recreational facility shall be accessible. Every recreational facility of each type on a site shall be considered to
determine the total number of each type that is required to be
accessible.
1109.12.4 Food service lines. Food service lines shall be
accessible. Where self-service shelves are provided, at least
50 percent, but not less than one, of each type provided shall
be accessible.
1109.12.5 Queue and waiting lines. Queue and waiting
lines servicing accessible counters or check-out aisles shall
be accessible.
1109.14.2 Facilities serving multiple buildings. In Group
R-2 and R-3 occupancies on a single site where multiple
buildings containing Type A units or Type B units are served
by recreational facilities, 25 percent, but not less than one,
of each type of recreational facility serving each building
shall be accessible. The total number of each type of recreational facility that is required to be accessible shall be
determined by considering every recreational facility of
each type serving each building on the site.
1109.13 Controls, operating mechanisms and hardware.
Controls, operating mechanisms and hardware intended for
operation by the occupant, including switches that control
lighting and ventilation and electrical convenience outlets, in
accessible spaces, along accessible routes or as parts of accessible elements shall be accessible.
Exceptions:
1109.14.3 Other occupancies. All recreational and sports
facilities not falling within the purview of Section
1109.14.1 or 1109.14.2 shall be accessible.
1. Operable parts that are intended for use only by service or maintenance personnel shall not be required to
be accessible.
1109.14.4 Recreational and sports facilities exceptions.
Recreational and sports facilities required to be accessible
shall be exempt from this chapter to the extent specified in
this section.
2. Electrical or communication receptacles serving a
dedicated use shall not be required to be accessible.
3. Where two or more outlets are provided in a kitchen
above a length of counter top that is uninterrupted by a
sink or appliance, one outlet shall not be required to
be accessible.
1109.14.4.1 Bowling lanes. An accessible route shall be
provided to at least 5 percent, but no less than one, of
each type of bowling lane.
4. Floor electrical receptacles shall not be required to be
accessible.
1109.14.4.2 Court sports. In court sports, at least one
accessible route shall directly connect both sides of the
court.
5. HVAC diffusers shall not be required to be accessible.
6. Except for light switches, where redundant controls
are provided for a single element, one control in each
space shall not be required to be accessible.
1109.14.4.3 Raised boxing or wrestling rings. Raised
boxing or wrestling rings are not required to be accessible.
7. Access doors or gates in barrier walls and fences protecting pools, spas and hot tubs shall be permitted to
have operable parts of the release of latch on
self-latching devices at 54 inches (1370 mm) maximum and 48 inches minimum above the finished floor
or ground, provided the self-latching devices are not
also self-locking devices, operated by means of a key,
electronic opener, or integral combination lock.
1109.14.4.4 Raised refereeing, judging and scoring
areas. Raised structures used solely for refereeing, judging or scoring a sport are not required to be accessible.
1109.14.4.5 Raised diving boards and diving platforms. Raised diving boards and diving platforms are
not required to be accessible.
2006 INTERNATIONAL BUILDING CODE®
246
11_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\11_ibc_2006.vp
Thursday, December 08, 2005 9:37:16 AM
12
➡
TOTAL CHECK-OUT AISLES OF
EACH FUNCTION
1109.13.1 Operable window. Where operable windows are
provided in rooms that are required to be accessible in accordance with Sections 1107.5.1.1, 1107.5.2.1, 1107.5.3.1,
1107.5.4, 1107.6.1.1, 1107.6.2.2.1 and 1107.6.4.1, at least
one window in each room shall be accessible and each
required operable window shall be accessible.
Color profile: Generic CMYK printer profile
Composite Default screen
ACCESSIBILITY
SECTION 1110
SIGNAGE
1110.1 Signs. Required accessible elements shall be identified
by the International Symbol of Accessibility at the following
locations:
1. Accessible parking spaces required by Section 1106.1
except where the total number of parking spaces provided is four or less.
2. Accessible passenger loading zones.
3. Accessible areas of refuge required by Section 1007.6.
4. Accessible rooms where multiple single-user toilet or
bathing rooms are clustered at a single location.
5. Accessible entrances where not all entrances are accessible.
6. Accessible check-out aisles where not all aisles are
accessible. The sign, where provided, shall be above the
check-out aisle in the same location as the check-out
aisle number or type of check-out identification.
7. Unisex toilet and bathing rooms.
8. Accessible dressing, fitting and locker rooms where not
all such rooms are accessible.
1110.2 Directional signage. Directional signage indicating
the route to the nearest like accessible element shall be provided at the following locations. These directional signs shall
include the International Symbol of Accessibility:
1. Inaccessible building entrances.
2. Inaccessible public toilets and bathing facilities.
3. Elevators not serving an accessible route.
4. At each separate-sex toilet and bathing room indicating
the location of the nearest unisex toilet or bathing room
where provided in accordance with Section 1109.2.1.
5. At exits and elevators serving a required accessible
space, but not providing an approved accessible means
of egress, signage shall be provided in accordance with
Section 1007.7.
1110.3 Other signs. Signage indicating special accessibility
provisions shall be provided as shown:
1. Each assembly area required to comply with Section
1108.2.6 shall provide a sign notifying patrons of the
availability of assistive listening systems.
Exception: Where ticket offices or windows are provided, signs are not required at each assembly area
provided that signs are displayed at each ticket office
or window informing patrons of the availability of
assistive listening systems.
2. At each door to an egress stairway, exit passageway and
exit discharge, signage shall be provided in accordance
with Section 1011.3.
3. At areas of refuge, signage shall be provided in accordance with Sections 1007.6.3 through 1007.6.5.
4. At areas for assisted rescue, signage shall be provided in
accordance with Section 1007.8.3.
2006 INTERNATIONAL BUILDING CODE®
11_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\11_ibc_2006.vp
Thursday, December 08, 2005 9:37:16 AM
247
13
Color profile: Generic CMYK printer profile
Composite Default screen
2006 INTERNATIONAL BUILDING CODE®
248
11_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\11_ibc_2006.vp
Thursday, December 08, 2005 9:37:16 AM
14
Color profile: Generic CMYK printer profile
Composite Default screen
CHAPTER 12
INTERIOR ENVIRONMENT
1203.2.1 Openings into attic. Exterior openings into the
attic space of any building intended for human occupancy
shall be covered with corrosion-resistant wire cloth screening, hardware cloth, perforated vinyl or similar material that
will prevent the entry of birds, squirrels, rodents, snakes and
other similar creatures. The openings therein shall be a minimum of 1/8 inch (3.2 mm) and shall not exceed 1/4 inch (6.4
mm). Where combustion air is obtained from an attic area, it
shall be in accordance with Chapter 7 of the International
Mechanical Code.
SECTION 1201
GENERAL
1201.1 Scope. The provisions of this chapter shall govern ventilation, temperature control, lighting, yards and courts, sound
transmission, room dimensions, surrounding materials and
rodent proofing associated with the interior spaces of buildings.
SECTION 1202
DEFINITIONS
1203.3 Under-floor ventilation. The space between the bottom of the floor joists and the earth under any building except
spaces occupied by a basement or cellar shall be provided with
ventilation openings through foundation walls or exterior
walls. Such openings shall be placed so as to provide cross ventilation of the under-floor space.
1202.1 General. The following words and terms shall, for the
purposes of this chapter and as used elsewhere in this code,
have the meanings shown herein.
SUNROOM ADDITION. A one-story addition added to an
existing building with a glazing area in excess of 40 percent of
the gross area of the structure’s exterior walls and roof.
THERMAL ISOLATION. A separation of conditioned
spaces, between a sunroom addition and a dwelling unit, consisting of existing or new wall(s), doors and/or windows.
1203.3.1 Openings for under-floor ventilation. The minimum net area of ventilation openings shall not be less than 1
square foot for each 150 square feet (0.67 m2 for each 100
m2) of crawl-space area. Ventilation openings shall be covered for their height and width with any of the following
materials, provided that the least dimension of the covering
shall not exceed 1/4 inch (6 mm):
SECTION 1203
VENTILATION
1. Perforated sheet metal plates not less than 0.070 inch
(1.8 mm) thick.
1203.1 General. Buildings shall be provided with natural ventilation in accordance with Section 1203.4, or mechanical ventilation in accordance with the International Mechanical Code.
2. Expanded sheet metal plates not less than 0.047 inch
(1.2 mm) thick.
3. Cast-iron grilles or gratings.
1203.2 Attic spaces. Enclosed attics and enclosed rafter spaces
formed where ceilings are applied directly to the underside of
roof framing members shall have cross ventilation for each
separate space by ventilating openings protected against the
entrance of rain and snow. Blocking and bridging shall be
arranged so as not to interfere with the movement of air. A minimum of 1 inch (25 mm) of airspace shall be provided between
the insulation and the roof sheathing. The net free ventilating
area shall not be less than 1/150 of the area of the space ventilated, with 50 percent of the required ventilating area provided
by ventilators located in the upper portion of the space to be
ventilated at least 3 feet (914 mm) above eave or cornice vents
with the balance of the required ventilation provided by eave or
cornice vents.
Exception: The minimum required net free ventilating area
shall be 1/300 of the area of the space ventilated, provided a
vapor retarder having a transmission rate not exceeding 1
perm in accordance with ASTM E 96 is installed on the
warm side of the attic insulation and provided 50 percent of
the required ventilating area provided by ventilators located
in the upper portion of the space to be ventilated at least 3
feet (914 mm) above eave or cornice vents, with the balance
of the required ventilation provided by eave or cornice
vents.
2006 INTERNATIONAL BUILDING CODE®
12_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\12_ibc_2006.vp
Wednesday, December 07, 2005 10:55:19 AM
4. Extruded load-bearing vents.
5. Hardware cloth of 0.035 inch (0.89 mm) wire or
heavier.
6. Corrosion-resistant wire mesh, with the least dimension not exceeding 1/8 inch (3.2 mm).
1203.3.2 Exceptions. The following are exceptions to Sections 1203.3 and 1203.3.1:
1. Where warranted by climatic conditions, ventilation
openings to the outdoors are not required if ventilation openings to the interior are provided.
2. The total area of ventilation openings is permitted to
be reduced to 1/1,500 of the under-floor area where the
ground surface is treated with an approved vapor
retarder material and the required openings are placed
so as to provide cross ventilation of the space. The
installation of operable louvers shall not be prohibited.
3. Ventilation openings are not required where continuously operated mechanical ventilation is provided at a
rate of 1.0 cubic foot per minute (cfm) for each 50
square feet (1.02 L/s for each 10 m2) of crawl-space
249
1
Color profile: Generic CMYK printer profile
Composite Default screen
INTERIOR ENVIRONMENT
floor area and the ground surface is covered with an
approved vapor retarder.
4. Ventilation openings are not required when the
ground surface is covered with an approved vapor
retarder, the perimeter walls are insulated and the
space is conditioned in accordance with the International Energy Conservation Code.
5. For buildings in flood hazard areas as established in
Section 1612.3, the openings for under-floor ventilation shall be deemed as meeting the flood opening
requirements of ASCE 24 provided that the ventilation openings are designed and installed in accordance with ASCE 24.
1203.4 Natural ventilation. Natural ventilation of an occupied space shall be through windows, doors, louvers or other
openings to the outdoors. The operating mechanism for such
openings shall be provided with ready access so that the openings are readily controllable by the building occupants.
1203.5 Other ventilation and exhaust systems. Ventilation
and exhaust systems for occupancies and operations involving
flammable or combustible hazards or other contaminant
sources as covered in the International Mechanical Code or the
International Fire Code shall be provided as required by both
codes.
SECTION 1204
TEMPERATURE CONTROL
1204.1 Equipment and systems. Interior spaces intended for
human occupancy shall be provided with active or passive
space-heating systems capable of maintaining a minimum
indoor temperature of 68°F (20°C) at a point 3 feet (914 mm)
above the floor on the design heating day.
Exception: Interior spaces where the primary purpose is
not associated with human comfort.
1203.4.1 Ventilation area required. The minimum
openable area to the outdoors shall be 4 percent of the floor
area being ventilated.
SECTION 1205
LIGHTING
1203.4.1.1 Adjoining spaces. Where rooms and spaces
without openings to the outdoors are ventilated through
an adjoining room, the opening to the adjoining room
shall be unobstructed and shall have an area of not less
than 8 percent of the floor area of the interior room or
space, but not less than 25 square feet (2.3 m2). The minimum openable area to the outdoors shall be based on the
total floor area being ventilated.
1205.1 General. Every space intended for human occupancy
shall be provided with natural light by means of exterior glazed
openings in accordance with Section 1205.2 or shall be provided with artificial light in accordance with Section 1205.3.
Exterior glazed openings shall open directly onto a public way
or onto a yard or court in accordance with Section 1206.
Exception: Exterior openings required for ventilation shall be permitted to open into a thermally isolated sunroom addition or patio cover provided that
the openable area between the sunroom addition or
patio cover and the interior room shall have an area of
not less than 8 percent of the floor area of the interior
room or space, but not less than 20 square feet (1.86
m2). The minimum openable area to the outdoors
shall be based on the total floor area being ventilated.
1205.2.1 Adjoining spaces. For the purpose of natural
lighting, any room is permitted to be considered as a portion
of an adjoining room where one-half of the area of the common wall is open and unobstructed and provides an opening
of not less than one-tenth of the floor area of the interior
room or 25 square feet (2.32 m2), whichever is greater.
1205.2 Natural light. The minimum net glazed area shall not
be less than 8 percent of the floor area of the room served.
Exception: Openings required for natural light shall be
permitted to open into a thermally isolated sunroom
addition or patio cover where the common wall provides
a glazed area of not less than one-tenth of the floor area of
the interior room or 20 square feet (1.86 m2), whichever
is greater.
1203.4.1.2 Openings below grade. Where openings
below grade provide required natural ventilation, the
outside horizontal clear space measured perpendicular to
the opening shall be one and one-half times the depth of
the opening. The depth of the opening shall be measured
from the average adjoining ground level to the bottom of
the opening.
1205.2.2 Exterior openings. Exterior openings required by
Section 1205.2 for natural light shall open directly onto a
public way, yard or court, as set forth in Section 1206.
Exceptions:
1203.4.2 Contaminants exhausted. Contaminant sources
in naturally ventilated spaces shall be removed in accordance with the International Mechanical Code and the
International Fire Code.
1. Required exterior openings are permitted to open
into a roofed porch where the porch:
1.1. Abuts a public way, yard or court.
1203.4.2.1 Bathrooms. Rooms containing bathtubs,
showers, spas and similar bathing fixtures shall be
mechanically ventilated in accordance with the International Mechanical Code.
1.2. Has a ceiling height of not less than 7 feet
(2134 mm).
1.3. Has a longer side at least 65 percent open
and unobstructed.
1203.4.3 Openings on yards or courts. Where natural ventilation is to be provided by openings onto yards or courts,
such yards or courts shall comply with Section 1206.
2. Skylights are not required to open directly onto a
public way, yard or court.
2006 INTERNATIONAL BUILDING CODE®
250
12_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\12_ibc_2006.vp
Wednesday, December 07, 2005 10:55:20 AM
2
Color profile: Generic CMYK printer profile
Composite Default screen
INTERIOR ENVIRONMENT
1205.3 Artificial light. Artificial light shall be provided that is
adequate to provide an average illumination of 10 foot-candles
(107 lux) over the area of the room at a height of 30 inches (762
mm) above the floor level.
1205.4 Stairway illumination. Stairways within dwelling
units and exterior stairways serving a dwelling unit shall have
an illumination level on tread runs of not less than 1 foot-candle
(11 lux). Stairs in other occupancies shall be governed by
Chapter 10.
1205.4.1 Controls. The control for activation of the
required stairway lighting shall be in accordance with the
ICC Electrical Code.
1205.5 Emergency egress lighting. The means of egress shall
be illuminated in accordance with Section 1006.1.
1207.2 Air-borne sound. Walls, partitions and floor/ceiling
assemblies separating dwelling units from each other or from
public or service areas shall have a sound transmission class
(STC) of not less than 50 (45 if field tested) for air-borne noise
when tested in accordance with ASTM E 90. Penetrations or
openings in construction assemblies for piping; electrical
devices; recessed cabinets; bathtubs; soffits; or heating, ventilating or exhaust ducts shall be sealed, lined, insulated or otherwise treated to maintain the required ratings. This requirement
shall not apply to dwelling unit entrance doors; however, such
doors shall be tight fitting to the frame and sill.
1207.3 Structure-borne sound. Floor/ceiling assemblies
between dwelling units or between a dwelling unit and a public
or service area within the structure shall have an impact insulation class (IIC) rating of not less than 50 (45 if field tested)
when tested in accordance with ASTM E 492.
SECTION 1206
YARDS OR COURTS
1206.1 General. This section shall apply to yards and courts
adjacent to exterior openings that provide natural light or ventilation. Such yards and courts shall be on the same property as
the building.
1206.2 Yards. Yards shall not be less than 3 feet (914 mm) in
width for one- and two-story buildings. For buildings more
than two stories in height, the minimum width of the yard shall
be increased at the rate of 1 foot (305 mm) for each additional
story. For buildings exceeding 14 stories in height, the required
width of the yard shall be computed on the basis of 14 stories.
1206.3 Courts. Courts shall not be less than 3 feet (914 mm) in
width. Courts having windows opening on opposite sides shall
not be less than 6 feet (1829 mm) in width. Courts shall not be
less than 10 feet (3048 mm) in length unless bounded on one
end by a public way or yard. For buildings more than two stories in height, the court shall be increased 1 foot (305 mm) in
width and 2 feet (310 mm) in length for each additional story.
For buildings exceeding 14 stories in height, the required
dimensions shall be computed on the basis of 14 stories.
1206.3.1 Court access. Access shall be provided to the bottom of courts for cleaning purposes.
1206.3.2 Air intake. Courts more than two stories in height
shall be provided with a horizontal air intake at the bottom
not less than 10 square feet (0.93 m2) in area and leading to
the exterior of the building unless abutting a yard or public
way.
SECTION 1208
INTERIOR SPACE DIMENSIONS
1208.1 Minimum room widths. Habitable spaces, other than a
kitchen, shall not be less than 7 feet (2134 mm) in any plan
dimension. Kitchens shall have a clear passageway of not less
than 3 feet (914 mm) between counter fronts and appliances or
counter fronts and walls.
1208.2 Minimum ceiling heights. Occupiable spaces, habitable spaces and corridors shall have a ceiling height of not less
than 7 feet 6 inches (2286 mm). Bathrooms, toilet rooms, kitchens, storage rooms and laundry rooms shall be permitted to
have a ceiling height of not less than 7 feet (2134 mm).
Exceptions:
1. In one- and two-family dwellings, beams or girders
spaced not less than 4 feet (1219 mm) on center and
projecting not more than 6 inches (152 mm) below the
required ceiling height.
2. If any room in a building has a sloped ceiling, the prescribed ceiling height for the room is required in
one-half the area thereof. Any portion of the room
measuring less than 5 feet (1524 mm) from the finished floor to the ceiling shall not be included in any
computation of the minimum area thereof.
3. Mezzanines constructed in accordance with Section
505.1.
1206.3.3 Court drainage. The bottom of every court shall
be properly graded and drained to a public sewer or other
approved disposal system complying with the International
Plumbing Code.
1208.2.1 Furred ceiling. Any room with a furred ceiling
shall be required to have the minimum ceiling height in
two-thirds of the area thereof, but in no case shall the height
of the furred ceiling be less than 7 feet (2134 mm).
SECTION 1207
SOUND TRANSMISSION
1208.3 Room area. Every dwelling unit shall have at least one
room that shall have not less than 120 square feet (13.9 m2) of
net floor area. Other habitable rooms shall have a net floor area
of not less than 70 square feet (6.5 m2).
1207.1 Scope. This section shall apply to common interior
walls, partitions and floor/ceiling assemblies between adjacent
dwelling units or between dwelling units and adjacent public
areas such as halls, corridors, stairs or service areas.
2006 INTERNATIONAL BUILDING CODE®
12_ibc_2006_pg251.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\12_ibc_2006.vp
Monday, December 19, 2005 10:56:21 AM
Exception: Every kitchen in a one- and two-family dwelling shall have not less than 50 square feet (4.64 m2) of gross
floor area.
251
3
Color profile: Generic CMYK printer profile
Composite Default screen
INTERIOR ENVIRONMENT
1208.4 Efficiency dwelling units. An efficiency living unit
shall conform to the requirements of the code except as modified herein:
1. The unit shall have a living room of not less than 220
square feet (20.4 m2) of floor area. An additional 100
square feet (9.3 m2) of floor area shall be provided for
each occupant of such unit in excess of two.
1210.4 Waterproof joints. Built-in tubs with showers shall
have waterproof joints between the tub and adjacent wall.
1210.5 Toilet rooms. Toilet rooms shall not open directly into a
room used for the preparation of food for service to the public.
2. The unit shall be provided with a separate closet.
3. The unit shall be provided with a kitchen sink, cooking appliance and refrigeration facilities, each having
a clear working space of not less than 30 inches (762
mm) in front. Light and ventilation conforming to this
code shall be provided.
4. The unit shall be provided with a separate bathroom
containing a water closet, lavatory and bathtub or
shower.
SECTION 1209
ACCESS TO UNOCCUPIED SPACES
1209.1 Crawl spaces. Crawl spaces shall be provided with a
minimum of one access opening not less than 18 inches by 24
inches (457 mm by 610 mm).
1209.2 Attic spaces. An opening not less than 20 inches by 30
inches (559 mm by 762 mm) shall be provided to any attic area
having a clear height of over 30 inches (762 mm). A 30-inch
(762 mm) minimum clear headroom in the attic space shall be
provided at or above the access opening.
1209.3 Mechanical appliances. Access to mechanical appliances installed in under-floor areas, in attic spaces and on roofs
or elevated structures shall be in accordance with the International Mechanical Code.
SECTION 1210
SURROUNDING MATERIALS
1210.1 Floors. In other than dwelling units, toilet and bathing
room floors shall have a smooth, hard, nonabsorbent surface
that extends upward onto the walls at least 6 inches (152 mm).
1210.2 Walls. Walls within 2 feet (610 mm) of urinals and
water closets shall have a smooth, hard, nonabsorbent surface,
to a height of 4 feet (1219 mm) above the floor, and except for
structural elements, the materials used in such walls shall be of
a type that is not adversely affected by moisture.
Exceptions:
1. Dwelling units and sleeping units.
2. Toilet rooms that are not accessible to the public and
which have not more than one water closet.
Accessories such as grab bars, towel bars, paper dispensers
and soap dishes, provided on or within walls, shall be installed
and sealed to protect structural elements from moisture.
1210.3 Showers. Shower compartments and walls above bathtubs with installed shower heads shall be finished with a
smooth, nonabsorbent surface to a height not less than 70
inches (1778 mm) above the drain inlet.
2006 INTERNATIONAL BUILDING CODE®
252
12_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\12_ibc_2006.vp
Wednesday, December 07, 2005 10:55:20 AM
4
Color profile: Generic CMYK printer profile
Composite Default screen
CHAPTER 13
ENERGY EFFICIENCY
SECTION 1301
GENERAL
1301.1 Scope. This chapter governs the design and construction of buildings for energy efficiency.
1301.1.1 Criteria. Buildings shall be designed and constructed in accordance with the International Energy Conservation Code.
2006 INTERNATIONAL BUILDING CODE®
13_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\13_ibc_2006.vp
Wednesday, December 07, 2005 10:54:31 AM
253
1
Color profile: Generic CMYK printer profile
Composite Default screen
2006 INTERNATIONAL BUILDING CODE®
254
13_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\13_ibc_2006.vp
Wednesday, December 07, 2005 10:54:31 AM
2
Color profile: Generic CMYK printer profile
Composite Default screen
CHAPTER 14
EXTERIOR WALLS
SECTION 1401
GENERAL
1401.1 Scope. The provisions of this chapter shall establish the
minimum requirements for exterior walls; exterior wall coverings; exterior wall openings; exterior windows and doors;
architectural trim; balconies and similar projections; and bay
and oriel windows.
cific assembly including joints, seams, attachments, substrate,
framing and other details as appropriate to a particular design.
VENEER. A facing attached to a wall for the purpose of providing ornamentation, protection or insulation, but not counted
as adding strength to the wall.
VINYL SIDING. A shaped material, made principally from
rigid polyvinyl chloride (PVC), that is used as an exterior wall
covering.
SECTION 1402
DEFINITIONS
1402.1 General. The following words and terms shall, for the
purposes of this chapter and as used elsewhere in this code,
have the meanings shown herein.
WATER-RESISTIVE BARRIER. A material behind an
exterior wall covering that is intended to resist liquid water that
has penetrated behind the exterior covering from futher intruding into the exterior wall assembly.
ADHERED MASONRY VENEER. Veneer secured and supported through the adhesion of an approved bonding material
applied to an approved backing.
SECTION 1403
PERFORMANCE REQUIREMENTS
ANCHORED MASONRY VENEER. Veneer secured with
approved mechanical fasteners to an approved backing.
BACKING. The wall or surface to which the veneer is secured.
EXTERIOR WALL. A wall, bearing or nonbearing, that is
used as an enclosing wall for a building, other than a fire wall,
and that has a slope of 60 degrees (1.05 rad) or greater with the
horizontal plane.
EXTERIOR WALL COVERING. A material or assembly of
materials applied on the exterior side of exterior walls for the
purpose of providing a weather-resisting barrier, insulation or
for aesthetics, including but not limited to, veneers, siding,
exterior insulation and finish systems, architectural trim and
embellishments such as cornices, soffits, facias, gutters and
leaders.
1403.2 Weather protection. Exterior walls shall provide the
building with a weather-resistant exterior wall envelope. The
exterior wall envelope shall include flashing, as described in
Section 1405.3. The exterior wall envelope shall be designed
and constructed in such a manner as to prevent the accumulation of water within the wall assembly by providing a
water-resistive barrier behind the exterior veneer, as described
in Section 1404.2, and a means for draining water that enters
the assembly to the exterior. Protection against condensation in
the exterior wall assembly shall be provided in accordance with
the International Energy Conservation Code.
Exceptions:
EXTERIOR WALL ENVELOPE. A system or assembly of
exterior wall components, including exterior wall finish materials, that provides protection of the building structural members, including framing and sheathing materials, and
conditioned interior space, from the detrimental effects of the
exterior environment.
FIBER CEMENT SIDING. A manufactured, fiber-reinforcing product made with an inorganic hydraulic or calcium silicate binder formed by chemical reaction and reinforced with
organic or inorganic nonasbestos fibers, or both. Additives that
enhance manufacturing or product performance are permitted.
Fiber cement siding products have either smooth or textured
faces and are intended for exterior wall and related applications.
METAL COMPOSITE MATERIAL (MCM). A factory-manufactured panel consisting of metal skins bonded to
both faces of a plastic core.
1. A weather-resistant exterior wall envelope shall not
be required over concrete or masonry walls designed
in accordance with Chapters 19 and 21, respectively.
2. Compliance with the requirements for a means of
drainage, and the requirements of Sections 1404.2
and 1405.3, shall not be required for an exterior wall
envelope that has been demonstrated through testing
to resist wind-driven rain, including joints, penetrations and intersections with dissimilar materials, in
accordance with ASTM E 331 under the following
conditions:
2.1. Exterior wall envelope test assemblies shall
include at least one opening, one control joint,
one wall/eave interface and one wall sill. All
tested openings and penetrations shall be representative of the intended end-use configuration.
2.2. Exterior wall envelope test assemblies shall
be at least 4 feet by 8 feet (1219 mm by 2438
mm) in size.
METAL COMPOSITE MATERIAL (MCM) SYSTEM.
An exterior wall finish system fabricated using MCM in a spe2006 INTERNATIONAL BUILDING CODE®
14_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Wednesday, December 07, 2005 10:54:01 AM
1403.1 General. The provisions of this section shall apply to
exterior walls, wall coverings and components thereof.
255
1
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
2.3. Exterior wall envelope assemblies shall be
tested at a minimum differential pressure of
6.24 pounds per square foot (psf) (0.297
kN/m2).
2.4. Exterior wall envelope assemblies shall be
subjected to a minimum test exposure duration of 2 hours.
1404.4 Masonry. Exterior walls of masonry construction shall
be designed and constructed in accordance with this section
and Chapter 21. Masonry units, mortar and metal accessories
used in anchored and adhered veneer shall meet the physical
requirements of Chapter 21. The backing of anchored and
adhered veneer shall be of concrete, masonry, steel framing or
wood framing.
The exterior wall envelope design shall be considered to resist wind-driven rain where the results of
testing indicate that water did not penetrate control
joints in the exterior wall envelope, joints at the perimeter of openings or intersections of terminations
with dissimilar materials.
1404.5 Metal. Exterior walls of formed steel construction,
structural steel or lightweight metal alloys shall be designed in
accordance with Chapters 22 and 20, respectively.
➡ 1403.3 Structural. Exterior walls, and the associated open-
1404.5.2 Cold-rolled copper. Copper shall conform to the
requirements of ASTM B 370.
ings, shall be designed and constructed to resist safely the
superimposed loads required by Chapter 16.
1404.5.3 Lead-coated copper. Lead-coated copper shall
conform to the requirements of ASTM B 101.
1403.4 Fire resistance. Exterior walls shall be fire-resistance
rated as required by other sections of this code with opening
protection as required by Chapter 7.
1404.6 Concrete. Exterior walls of concrete construction shall
be designed and constructed in accordance with Chapter 19.
1403.5 Flood resistance. For buildings in flood hazard areas as
established in Section 1612.3, exterior walls extending below
the design flood elevation shall be resistant to water damage.
Wood shall be pressure-preservative treated in accordance with
AWPA U1 for the species, product and end use using a preservative listed in Section 4 of AWPA U1 or decay-resistant heartwood of redwood, black locust or cedar.
1403.6 Flood resistance for high-velocity wave action areas.
For buildings in flood hazard areas subject to high-velocity
wave action as established in Section 1612.3, electrical,
mechanical and plumbing system components shall not be
mounted on or penetrate through exterior walls that are
designed to break away under flood loads.
SECTION 1404
MATERIALS
1404.1 General. Materials used for the construction of exterior
walls shall comply with the provisions of this section. Materials not prescribed herein shall be permitted, provided that any
such alternative has been approved.
1404.2 Water-resistive barrier. A minimum of one layer of
No.15 asphalt felt, complying with ASTM D 226 for Type 1
felt or other approved materials, shall be attached to the studs or
sheathing, with flashing as described in Section 1405.3, in such
a manner as to provide a continuous water-resistive barrier
behind the exterior wall veneer.
1404.3 Wood. Exterior walls of wood construction shall be
designed and constructed in accordance with Chapter 23.
1404.3.1 Basic hardboard. Basic hardboard shall conform
to the requirements of AHA A135.4.
1404.3.2 Hardboard siding. Hardboard siding shall conform to the requirements of AHA A135.6 and, where used
structurally, shall be so identified by the label of an
approved agency.
1404.5.1 Aluminum siding. Aluminum siding shall conform to the requirements of AAMA 1402.
1404.7 Glass-unit masonry. Exterior walls of glass-unit
masonry shall be designed and constructed in accordance with
Chapter 21.
1404.8 Plastics. Plastic panel, apron or spandrel walls as
defined in this code shall not be limited in thickness, provided
that such plastics and their assemblies conform to the requirements of Chapter 26 and are constructed of approved
weather-resistant materials of adequate strength to resist the
wind loads for cladding specified in Chapter 16.
1404.9 Vinyl siding. Vinyl siding shall be certified and labeled
as conforming to the requirements of ASTM D 3679 by an
approved quality control agency.
1404.10 Fiber cement siding. Fiber cement siding shall conform to the requirements of ASTM C 1186 and shall be so
identified on labeling listing an approved quality control
agency.
SECTION 1405
INSTALLATION OF WALL COVERINGS
1405.1 General. Exterior wall coverings shall be designed and
constructed in accordance with the applicable provisions of
this section.
1405.2 Weather protection. Exterior walls shall provide
weather protection for the building. The materials of the minimum nominal thickness specified in Table 1405.2 shall be
acceptable as approved weather coverings.
1405.3 Flashing. Flashing shall be installed in such a manner
so as to prevent moisture from entering the wall or to redirect it
to the exterior. Flashing shall be installed at the perimeters of
exterior door and window assemblies, penetrations and terminations of exterior wall assemblies, exterior wall intersections
with roofs, chimneys, porches, decks, balconies and similar
projections and at built-in gutters and similar locations where
moisture could enter the wall. Flashing with projecting flanges
shall be installed on both sides and the ends of copings, under
sills and continuously above projecting trim.
2006 INTERNATIONAL BUILDING CODE®
256
14_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Wednesday, December 07, 2005 10:54:02 AM
2
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
TABLE 1405.2
MINIMUM THICKNESS OF WEATHER COVERINGS
COVERING TYPE
1405.3.1 Exterior wall pockets. In exterior walls of buildings or structures, wall pockets or crevices in which moisture can accumulate shall be avoided or protected with caps
or drips, or other approved means shall be provided to prevent water damage.
MINIMUM THICKNESS
(inches)
Adhered masonry veneer
0.25
Aluminum siding
0.019
Anchored masonry veneer
2.625
Asbestos-cement boards
0.125
Asbestos shingles
0.156
Cold-rolled copperd
0.0216 nominal
Copper shinglesd
0.0162 nominal
Exterior plywood (with sheathing)
0.313
Exterior plywood (without sheathing)
See Section 2304.6
Fiber cement lap siding
0.25c
Fiber cement panel siding
0.25c
Fiberboard siding
0.5
Glass-fiber reinforced concrete panels
0.375
Hardboard sidingc
0.25
High-yield copperd
0.0162 nominal
Lead-coated copperd
0.0216 nominal
Lead-coated high-yield copper
0.0162 nominal
Marble slabs
1405.3.2 Masonry. Flashing and weepholes shall be
located in the first course of masonry above finished ground
level above the foundation wall or slab, and other points of
support, including structural floors, shelf angles and lintels
where anchored veneers are designed in accordance with
Section 1405.5.
1405.4 Wood veneers. Wood veneers on exterior walls of
buildings of Type I, II, III and IV construction shall be not less
than 1 inch (25 mm) nominal thickness, 0.438-inch (11.1 mm)
exterior hardboard siding or 0.375-inch (9.5 mm) exterior-type
wood structural panels or particleboard and shall conform to
the following:
1. The veneer shall not exceed three stories in height, measured from the grade plane. Where fire-retardant-treated
wood is used, the height shall not exceed four stories.
2. T h e v e n e e r i s a t t a c h e d t o o r f u r r e d f r o m a
noncombustible backing that is fire-resistance rated as
required by other provisions of this code.
3. Where open or spaced wood veneers (without concealed
spaces) are used, they shall not project more than 24
inches (610 mm) from the building wall.
1
Particleboard (with sheathing)
See Section 2304.6
Particleboard (without sheathing)
See Section 2304.6
Precast stone facing
0.625
Steel (approved corrosion resistant)
0.0149
Stone (cast artificial)
1.5
Stone (natural)
2
Structural glass
0.344
1405.5 Anchored masonry veneer. Anchored masonry
veneer shall comply with the provisions of Sections 1405.5,
1405.6, 1405.7 and 1405.8 and Sections 6.1 and 6.2 of ACI
530/ASCE 5/TMS 402.
1405.5.1 Tolerances. Anchored masonry veneers in accordance with Chapter 14 are not required to meet the tolerances in Article 3.3 G1 of ACI 530.1/ASCE 6/TMS 602.
Stucco or exterior portland cement plaster
1405.5.2 Seismic requirements. Anchored masonry
veneer located in Seismic Design Category C, E or F shall
conform to the requirements of Section 6.2.2.10 of ACI530/
ASCE5/ TMS 402. Anchored masonry veneer located in
Seismic Design Category D shall conform to the requirements for Seismic Design Category E or F.
Three-coat work over:
Metal plaster base
0.875b
Unit masonry
0.625b
Cast-in-place or precast concrete
0.625b
Two-coat work over:
Unit masonry
0.5b
Cast-in-place or precast concrete
0.375b
Terra cotta (anchored)
1
Terra cotta (adhered)
0.25
Vinyl siding
0.035
Wood shingles
1405.6 Stone veneer. Stone veneer units not exceeding 10
inches (254 mm) in thickness shall be anchored directly to
masonry, concrete or to stud construction by one of the following methods:
0.375
a
Wood siding (without sheathing)
0.5
For SI: 1 inch = 25.4 mm.
a. Wood siding of thicknesses less than 0.5 inch shall be placed over sheathing
that conforms to Section 2304.6.
b. Exclusive of texture.
c. As measured at the bottom of decorative grooves.
d. 16 ounces per square foot for cold-rolled copper and lead-coated copper, 12
ounces per square foot for copper shingles, high-yield copper and
lead-coated high-yield copper.
2006 INTERNATIONAL BUILDING CODE®
14_ibc_2006_pg257.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Monday, December 19, 2005 10:58:09 AM
1. With concrete or masonry backing, anchor ties shall be
not less than 0.1055-inch (2.68 mm) corrosion-resistant
wire, or approved equal, formed beyond the base of the
backing. The legs of the loops shall be not less than 6
inches (152 mm) in length bent at right angles and laid in
the mortar joint, and spaced so that the eyes or loops are
12 inches (305 mm) maximum on center (o.c.) in both
directions. There shall be provided not less than a
0.1055-inch (2.68 mm) corrosion-resistant wire tie, or
approved equal, threaded through the exposed loops for
every 2 square feet (0.2 m2) of stone veneer. This tie shall
be a loop having legs not less than 15 inches (381 mm) in
length bent so that it will lie in the stone veneer mortar
257
3
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
joint. The last 2 inches (51 mm) of each wire leg shall
have a right-angle bend. One-inch (25 mm) minimum
thickness of cement grout shall be placed between the
backing and the stone veneer.
backing wall and the space shall be filled solidly with portland
cement grout and pea gravel. Immediately prior to setting, the
backing wall and the facing shall be drenched with clean water
and shall be distinctly damp when the grout is poured.
2. With stud backing, a 2-inch by 2-inch (51 by 51 mm)
0.0625-inch (1.59 mm) corrosion-resistant wire mesh
with two layers of water-resistive barrier in accordance
with Section 1404.2 shall be applied directly to wood
studs spaced a maximum of 16 inches (406 mm) o.c. On
studs, the mesh shall be attached with 2-inch-long (51
mm) corrosion-resistant steel wire furring nails at 4
inches (102 mm) o.c. providing a minimum 1.125-inch
(29 mm) penetration into each stud and with 8d common
nails at 8 inches (203 mm) o.c. into top and bottom plates
or with equivalent wire ties. There shall be not less than a
0.1055-inch (2.68 mm) corrosion-resistant wire, or
approved equal, looped through the mesh for every 2
square feet (0.2 m2) of stone veneer. This tie shall be a
loop having legs not less than 15 inches (381 mm) in
length, so bent that it will lie in the stone veneer mortar
joint. The last 2 inches (51 mm) of each wire leg shall
have a right-angle bend. One-inch (25 mm) minimum
thickness of cement grout shall be placed between the
backing and the stone veneer.
1405.9 Adhered masonry veneer. Adhered masonry veneer
shall comply with the applicable requirements in Section
1405.9.1 and Sections 6.1 and 6.3 of ACI 530/ASCE 5/TMS
402.
1405.9.1 Interior adhered masonry veneers. Interior
adhered masonry veneers shall have a maximum weight of
20 psf (0.958 kg/m2) and shall be installed in accordance
with Section 1405.9. Where the interior adhered masonry
veneer is supported by wood construction, the supporting
members shall be designed to limit deflection to 1/600 of the
span of the supporting members.
1405.10 Metal veneers. Veneers of metal shall be fabricated
from approved corrosion-resistant materials or shall be protected front and back with porcelain enamel, or otherwise be
treated to render the metal resistant to corrosion. Such veneers
shall not be less than 0.0149-inch (0.378 mm) nominal thickness sheet steel mounted on wood or metal furring strips or
approved sheathing on the wood construction.
1405.10.1 Attachment. Exterior metal veneer shall be
securely attached to the supporting masonry or framing
members with corrosion-resistant fastenings, metal ties or
by other approved devices or methods. The spacing of the
fastenings or ties shall not exceed 24 inches (610 mm) either
vertically or horizontally, but where units exceed 4 square
feet (0.4 m2) in area there shall be not less than four attachments per unit. The metal attachments shall have a
cross-sectional area not less than provided by W 1.7 wire.
Such attachments and their supports shall be capable of
resisting a horizontal force in accordance with the wind
loads specified in Section 1609, but in no case less than 20
psf (0.958 kg/m2).
1405.7 Slab-type veneer. Slab-type veneer units not exceeding 2 inches (51 mm) in thickness shall be anchored directly to
masonry, concrete or stud construction. For veneer units of
marble, travertine, granite or other stone units of slab form ties
of corrosion-resistant dowels in drilled holes shall be located in
the middle third of the edge of the units, spaced a maximum of
24 inches (610 m) apart around the periphery of each unit with
not less than four ties per veneer unit. Units shall not exceed 20
square feet (1.9 m2) in area. If the dowels are not tight fitting,
the holes shall be drilled not more than 0.063 inch (1.6 mm)
larger in diameter than the dowel, with the hole countersunk to
a diameter and depth equal to twice the diameter of the dowel in
order to provide a tight-fitting key of cement mortar at the
dowel locations when the mortar in the joint has set. Veneer ties
shall be corrosion-resistant metal capable of resisting, in tension or compression, a force equal to two times the weight of
the attached veneer. If made of sheet metal, veneer ties shall be
not smaller in area than 0.0336 by 1 inch (0.853 by 25 mm) or,
if made of wire, not smaller in diameter than 0.1483-inch (3.76
mm) wire.
1405.8 Terra cotta. Anchored terra cotta or ceramic units not
less than 1.625 inches (41 mm) thick shall be anchored directly
to masonry, concrete or stud construction. Tied terra cotta or
ceramic veneer units shall be not less than 1.625 inches (41
mm) thick with projecting dovetail webs on the back surface
spaced approximately 8 inches (203 mm) o.c. The facing shall
be tied to the backing wall with corrosion-resistant metal
anchors of not less than No. 8 gage wire installed at the top of
each piece in horizontal bed joints not less than 12 inches (305
mm) nor more than 18 inches (457 mm) o.c.; these anchors
shall be secured to 0.25-inch (6.4 mm) corrosion-resistant pencil rods that pass through the vertical aligned loop anchors in
the backing wall. The veneer ties shall have sufficient strength
to support the full weight of the veneer in tension. The facing
shall be set with not less than a 2-inch (51 mm) space from the
1405.10.2 Weather protection. Metal supports for exterior
metal veneer shall be protected by painting, galvanizing or
by other equivalent coating or treatment. Wood studs, furring strips or other wood supports for exterior metal veneer
shall be approved pressure-treated wood or protected as
required in Section 1403.2. Joints and edges exposed to the
weather shall be caulked with approved durable waterproofing material or by other approved means to prevent penetration of moisture.
1405.10.3 Backup. Masonry backup shall not be required
for metal veneer except as is necessary to meet the fire-resistance requirements of this code.
1405.10.4 Grounding. Grounding of metal veneers on
buildings shall comply with the requirements of Chapter 27
of this code or the ICC Electrical Code.
1405.11 Glass veneer. The area of a single section of thin exterior structural glass veneer shall not exceed 10 square feet (0.93
m2) where it is not more than 15 feet (4572 mm) above the level
of the sidewalk or grade level directly below, and shall not
exceed 6 square feet (0.56 m2) where it is more than 15 feet
(4572 mm) above that level.
2006 INTERNATIONAL BUILDING CODE®
258
14_ibc_2006_pg258.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Thursday, January 05, 2006 12:47:24 PM
4
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
1405.11.7 Flashing. Exposed edges of thin exterior structural glass veneer shall be flashed with overlapping corrosion-resistant metal flashing and caulked with a waterproof
compound in a manner to effectively prevent the entrance of
moisture between the glass veneer and the backing.
1405.11.1 Length and height. The length or height of any
section of thin exterior structural glass veneer shall not
exceed 48 inches (1219 mm).
1405.11.2 Thickness. The thickness of thin exterior structural glass veneer shall be not less than 0.344 inch (8.7 mm).
1405.11.3 Application. Thin exterior structural glass
veneer shall be set only after backing is thoroughly dry and
after application of an approved bond coat uniformly over
the entire surface of the backing so as to effectively seal the
surface. Glass shall be set in place with an approved mastic
cement in sufficient quantity so that at least 50 percent of the
area of each glass unit is directly bonded to the backing by
mastic not less than 0.25 inch (6.4 mm) thick and not more
than 0.625 inch (15.9 mm) thick. The bond coat and mastic
shall be evaluated for compatibility and shall bond firmly
together.
1405.11.4 Installation at sidewalk level. Where glass
extends to a sidewalk surface, each section shall rest in an
approved metal molding, and be set at least 0.25 inch (6.4
mm) above the highest point of the sidewalk. The space
between the molding and the sidewalk shall be thoroughly
caulked and made water tight.
1405.11.4.1 Installation above sidewalk level. Where
thin exterior structural glass veneer is installed above the
level of the top of a bulkhead facing, or at a level more
than 36 inches (914 mm) above the sidewalk level, the
mastic cement binding shall be supplemented with
approved nonferrous metal shelf angles located in the
horizontal joints in every course. Such shelf angles shall
be not less than 0.0478-inch (1.2 mm) thick and not less
than 2 inches (51 mm) long and shall be spaced at
approved intervals, with not less than two angles for each
glass unit. Shelf angles shall be secured to the wall or
backing with expansion bolts, toggle bolts or by other
approved methods.
1405.11.5 Joints. Unless otherwise specifically approved
by the building official, abutting edges of thin exterior structural glass veneer shall be ground square. Mitered joints
shall not be used except where specifically approved for
wide angles. Joints shall be uniformly buttered with an
approved jointing compound and horizontal joints shall be
held to not less than 0.063 inch (1.6 mm) by an approved
nonrigid substance or device. Where thin exterior structural
glass veneer abuts nonresilient material at sides or top,
expansion joints not less than 0.25 inch (6.4 mm) wide shall
be provided.
1405.11.6 Mechanical fastenings. Thin exterior structural
glass veneer installed above the level of the heads of show
windows and veneer installed more than 12 feet (3658 mm)
above sidewalk level shall, in addition to the mastic cement
and shelf angles, be held in place by the use of fastenings at
each vertical or horizontal edge, or at the four corners of
each glass unit. Fastenings shall be secured to the wall or
backing with expansion bolts, toggle bolts or by other methods. Fastenings shall be so designed as to hold the glass
veneer in a vertical plane independent of the mastic cement.
Shelf angles providing both support and fastenings shall be
permitted.
2006 INTERNATIONAL BUILDING CODE®
14_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Wednesday, December 07, 2005 10:54:02 AM
1405.12 Exterior windows and doors. Windows and doors
installed in exterior walls shall conform to the testing and performance requirements of Section 1714.5.
1405.12.1 Installation. Windows and doors shall be
installed in accordance with approved manufacturer’s
instructions. Fastener size and spacing shall be provided in
such instructions and shall be calculated based on maximum
loads and spacing used in the tests.
1405.12.2 Window sills. In Occupancy Groups R-2 and
R-3, one- and two-family and multiple-family dwellings,
where the opening of the sill portion of an operable window
is located more than 72 inches (1829 mm) above the finished grade or other surface below, the lowest part of the
clear opening of the window shall be a minimum of 24
inches (610 mm) above the finished floor surface of the
room in which the window is located. Glazing between the
floor and a height of 24 inches (610 mm) shall be fixed or
have openings such that a 4-inch (102 mm) diameter sphere
cannot pass through.
Exception: Openings that are provided with window
guards that comply with ASTM F 2006 or F 2090.
1405.13 Vinyl siding. Vinyl siding conforming to the requirements of this section and complying with ASTM D 3679 shall
be permitted on exterior walls of buildings of Type V construction located in areas where the basic wind speed specified in
Chapter 16 does not exceed 100 miles per hour (45 m/s) and the
building height is less than or equal to 40 feet (12 192 mm) in
Exposure C. Where construction is located in areas where the
basic wind speed exceeds 100 miles per hour (45 m/s), or building heights are in excess of 40 feet (12 192 mm), tests or calculations indicating compliance with Chapter 16 shall be
submitted. Vinyl siding shall be secured to the building so as to
provide weather protection for the exterior walls of the building.
1405.13.1 Application. The siding shall be applied over
sheathing or materials listed in Section 2304.6. Siding shall
be applied to conform with the water-resistive barrier
requirements in Section 1403. Siding and accessories shall
be installed in accordance with approved manufacturer’s
instructions. Unless otherwise specified in the approved
manufacturer’s instructions, nails used to fasten the siding
and accessories shall have a minimum 0.313-inch (7.9 mm)
head diameter and 0.125-inch (3.18 mm) shank diameter.
The nails shall be corrosion resistant and shall be long
enough to penetrate the studs or nailing strip at least 0.75
inch (19 mm). Where the siding is installed horizontally, the
fastener spacing shall not exceed 16 inches (406 mm) horizontally and 12 inches (305 mm) vertically. Where the siding is installed vertically, the fastener spacing shall not
exceed 12 inches (305 mm) horizontally and 12 inches (305
mm) vertically.
259
5
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
1405.14 Cement plaster. Cement plaster applied to exterior
walls shall conform to the requirements specified in Chapter
25.
1406.2.1 Ignition resistance. Combustible exterior wall
coverings shall be tested in accordance with NFPA 268.
Exceptions:
1405.15 Fiber cement siding. Fiber cement siding complying with Section 1404.10 shall be permitted on exterior walls
of Type I, II, III, IV and V construction for wind pressure
resistance or wind speed exposures as indicated in the manufacturer’s compliance report and approved installation
instructions. Where specified, the siding shall be installed
over sheathing or materials listed in Section 2304.6 and shall
be installed to conform to the water-resistive barrier requirements in Section 1403. Siding and accessories shall be
installed in accordance with approved manufacturer’s
instructions. Unless otherwise specified in the approved manufacturer’s instructions, nails used to fasten the siding to
wood studs shall be corrosion-resistant round head smooth
shank and shall be long enough to penetrate the studs at least 1
inch (25 mm). For metal framing, all-weather screws shall be
used and shall penetrate the metal framing at least three full
threads.
1 Wood or wood-based products.
2. Other combustible materials covered with an exterior covering other than vinyl sidings listed in
Table 1405.2.
3. Aluminum having a minimum thickness of 0.019
inch (0.48 mm).
4. Exterior wall coverings on exterior walls of Type
V construction.
1406.2.1.1 Fire separation 5 feet or less. Where
installed on exterior walls having a fire separation distance of 5 feet (1524 mm) or less, combustible exterior
wall coverings shall not exhibit sustained flaming as
defined in NFPA 268.
1406.2.1.2 Fire separation greater than 5 feet. For fire
separation distances greater than 5 feet (1524 mm), an
assembly shall be permitted that has been exposed to a
reduced level of incident radiant heat flux in accordance
with the NFPA 268 test method without exhibiting sustained flaming. The minimum fire separation distance
required for the assembly shall be determined from Table
1406.2.1.2 based on the maximum tolerable level of incident radiant heat flux that does not cause sustained flaming of the assembly.
1405.16 Fastening. Weather boarding and wall coverings shall
be securely fastened with aluminum, copper, zinc, zinc-coated
or other approved corrosion-resistant fasteners in accordance
with the nailing schedule in Table 2304.9.1 or the approved
manufacturer’s installation instructions. Shingles and other
weather coverings shall be attached with appropriate standard-shingle nails to furring strips securely nailed to studs, or
with approved mechanically bonding nails, except where
sheathing is of wood not less than 1-inch (25 mm) nominal
thickness or of wood structural panels as specified in Table
2308.9.3(3).
TABLE 1406.2.1.2
MINIMUM FIRE SEPARATION FOR COMBUSTIBLE VENEERS
1405.17 Fiber cement siding.
1405.17.1 Panel siding. Panels shall be installed with the
long dimension parallel to framing. Vertical joints shall
occur over framing members and shall be sealed with caulking or covered with battens. Horizontal joints shall be
flashed with Z-flashing and blocked with solid wood framing.
1405.17.2 Horizontal lap siding. Lap siding shall be
lapped a minimum of 11/4 inches (32 mm) and shall have the
ends sealed with caulking, covered with an H-section joint
cover or located over a strip of flashing. Lap siding courses
shall be permitted to be installed with the fastener heads
exposed or concealed, according to approved manufacturers’ instructions.
TOLERABLE
LEVEL INCIDENT
RADIANT HEAT
ENERGY(kW/m2)
FIRE
SEPARATION
DISTANCE
(feet)
TOLERABLE
LEVEL INCIDENT
RADIANT HEAT
ENERGY(kW/m2)
5
6
7
8
9
10
11
12
13
14
15
12.5
11.8
11.0
10.3
9.6
8.9
8.3
7.7
7.2
6.7
6.3
16
17
18
19
20
21
22
23
24
25
5.9
5.5
5.2
4.9
4.6
4.4
4.1
3.9
3.7
3.5
For SI: 1 foot = 304.8 mm, 1 Btu/H2 ×°F = 0.0057 kW/m2 × K.
1406.2.2 Architectural trim. In buildings of Type I, II, III
and IV construction that do not exceed three stories or 40
feet (12 192 mm) in height above grade plane, exterior wall
coverings shall be permitted to be constructed of wood
where permitted by Section 1405.4 or other equivalent combustible material. Combustible exterior wall coverings,
other than fire-retardant-treated wood complying with Section 2303.2 for exterior installation, shall not exceed 10 percent of an exterior wall surface area where the fire
separation distance is 5 feet (1524 mm) or less. Architectural trim that exceeds 40 feet (12 192 mm) in height above
grade plane shall be constructed of approved
SECTION 1406
COMBUSTIBLE MATERIALS ON THE EXTERIOR
SIDE OF EXTERIOR WALLS
1406.1 General. Section 1406 shall apply to exterior wall coverings; balconies and similar projections; and bay and oriel
windows constructed of combustible materials.
1406.2 Combustible exterior wall coverings. Combustible
exterior wall coverings shall comply with this section.
Exception: Plastics complying with Chapter 26.
2006 INTERNATIONAL BUILDING CODE®
260
14_ibc_2006_pg260.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Thursday, January 05, 2006 12:49:25 PM
FIRE
SEPARATION
DISTANCE
(feet)
6
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
noncombustible materials and shall be secured to the wall
with metal or other approved noncombustible brackets.
oriel windows to provide cladding or weather resistance shall
comply with Sections 1407.4 through 1407.13.
1406.2.3 Location. Where combustible exterior wall covering is located along the top of exterior walls, such trim shall
be completely backed up by the exterior wall and shall not
extend over or above the top of exterior walls.
1407.3 Architectural trim and embellishments. MCM used
as architectural trim or embellishments shall comply with Sections 1407.7 through 1407.13.
1406.2.4 Fireblocking. Where the combustible exterior
wall covering is furred from the wall and forms a solid surface, the distance between the back of the covering and the
wall shall not exceed 1.625 inches (41 mm) and the space
thereby created shall be fireblocked in accordance with Section 717.
1407.5 Approval. Results of approved tests or an engineering
analysis shall be submitted to the building official to verify
compliance with the requirements of Chapter 16 for wind
loads.
➡ 1406.3 Balconies and similar projections. Balconies and
1407.6 Weather resistance. MCM systems shall comply with
Section 1403 and shall be designed and constructed to resist
wind and rain in accordance with this section and the manufacturer’s installation instructions.
similar projections of combustible construction other than
fire-retardant-treated wood shall be fire-resistance rated in
accordance with Table 601 for floor construction or shall be of
Type IV construction in accordance with Section 602.4. The
aggregate length shall not exceed 50 percent of the building’s
perimeter on each floor.
1407.7 Durability. MCM systems shall be constructed of
approved materials that maintain the performance characteristics required in Section 1407 for the duration of use.
Exceptions:
1. On buildings of Type I and II construction, three stories or less in height, fire-retardant-treated wood shall
be permitted for balconies, porches, decks and exterior stairways not used as required exits.
1407.8 Fire-resistance rating. Where MCM systems are used
on exterior walls required to have a fire-resistance rating in
accordance with Section 704, evidence shall be submitted to
the building official that the required fire-resistance rating is
maintained.
1407.9 Surface-burning characteristics. Unless otherwise
specified, MCM shall have a flame spread index of 75 or less
and a smoke-developed index of 450 or less when tested as an
assembly in the maximum thickness intended for use in accordance with ASTM E 84.
2. Untreated wood is permitted for pickets and rails or
similar guardrail devices that are limited to 42 inches
(1067 mm) in height.
3. Balconies and similar projections on buildings of
Type III, IV and V construction shall be permitted to
be of Type V construction, and shall not be required to
have a fire-resistance rating where sprinkler protection is extended to these areas.
1407.10 Type I, II, III and IV construction. Where installed
on buildings of Type I, II, III and IV construction, MCM systems shall comply with Sections 1407.10.1 through 1407.10.4,
or 1407.11.
4. Where sprinkler protection is extended to the balcony
areas, the aggregate length of the balcony on each
floor shall not be limited.
1407.10.1 Surface-burning characteristics. MCM shall
have a flame spread index of not more than 25 and a
smoke-developed index of not more than 450 when tested as
an assembly in the maximum thickness intended for use in
accordance with ASTM E 84.
1406.4 Bay windows and oriel windows. Bay and oriel windows shall conform to the type of construction required for the
building to which they are attached.
Exception: Fire-retardant-treated wood shall be permitted
on buildings three stories or less of Type I, II, III and IV construction.
SECTION 1407
METAL COMPOSITE MATERIALS (MCM)
1407.1 General. The provisions of this section shall govern the
materials, construction and quality of metal composite materials (MCM) for use as exterior wall coverings in addition to
other applicable requirements of Chapters 14 and 16.
1407.1.1 Plastic core. The plastic core of the MCM shall
not contain foam plastic insulation as defined in Section
2602.1.
1407.2 Exterior wall finish. MCM used as exterior wall finish
or as elements of balconies and similar projections and bay and
2006 INTERNATIONAL BUILDING CODE®
14_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Wednesday, December 07, 2005 10:54:03 AM
1407.4 Structural design. MCM systems shall be designed
and constructed to resist wind loads as required by Chapter 16
for components and cladding.
1407.10.2 Thermal barriers. MCM shall be separated
from the interior of a building by an approved thermal barrier consisting of 0.5-inch (12.7 mm) gypsum wallboard or
equivalent thermal barrier material that will limit the average temperature rise of the unexposed surface to not more
than 250°F (121°C) after 15 minutes of fire exposure in
accordance with the standard time-temperature curve of
ASTM E 119. The thermal barrier shall be installed in such a
manner that it will remain in place for not less than 15 minutes based on a test conducted in accordance with UL 1715.
1407.10.3 Thermal barrier not required. The thermal
barrier specified for MCM in Section 1407.10.2 is not
required where:
1. The MCM system is specifically approved based on
tests conducted in accordance with UL 1040 or UL
1715. Such testing shall be performed with the MCM
in the maximum thickness intended for use. The
MCM system shall include seams, joints and other
261
7
Color profile: Generic CMYK printer profile
Composite Default screen
EXTERIOR WALLS
typical details used in the installation and shall be
tested in the manner intended for use.
2. The MCM is used as elements of balconies and similar projections, architectural trim or embellishments.
1407.10.4 Full-scale tests. The MCM exterior wall assembly shall be tested in accordance with, and comply with, the
acceptance criteria of NFPA 285. Such testing shall be performed on the MCM system with the MCM in the maximum
thickness intended for use.
1407.11 Alternate conditions. MCM and MCM systems shall
not be required to comply with Sections 1407.10.1 through
1407.10.4 provided such systems comply with Section
1407.11.1 or 1407.11.2.
1407.11.1 Installations up to 40 feet in height. MCM shall
not be installed more than 40 feet (12 190 mm) in height
above the grade plane where installed in accordance with
Sections 1407.11.1.1 and 1407.11.1.2.
1407.11.1.1 Fire separation distance of 5 feet or less.
Where the fire separation distance is 5 feet (1524 mm) or
less, the area of MCM shall not exceed 10 percent of the
exterior wall surface.
1407.11.1.2 Fire separation distance greater than 5
feet. Where the fire separation distance is greater than 5
feet (1524 mm), there shall be no limit on the area of
exterior wall surface coverage using MCM.
1407.11.2 Installations up to 50 feet in height. MCM shall
not be installed more than 50 feet (15 240 mm) in height
above the grade plane where installed in accordance with
Sections 1407.11.2.1 and 1407.11.2.2.
1407.11.2.1 Self ignition temperature. MCM shall
have a self-ignition temperature of 650°F (343°C) or
greater when tested in accordance with ASTM D 1929.
1407.11.2.2 Limitations. Sections of MCM shall not
exceed 300 square feet (27.9 m2) in area and shall be separated by a minimum of 4 feet (1219 mm) vertically.
1407.12 Type V construction. MCM shall be permitted to be
installed on buildings of Type V construction.
1407.13 Labeling. MCM shall be labeled in accordance with
Section 1703.5.
2006 INTERNATIONAL BUILDING CODE®
262
14_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\14_ibc_2006.vp
Wednesday, December 07, 2005 10:54:03 AM
8
Color profile: Generic CMYK printer profile
Composite Default screen
CHAPTER 15
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
ROOF COVERING. The covering applied to the roof deck
for weather resistance, fire classification or appearance.
SECTION 1501
GENERAL
1501.1 Scope. The provisions of this chapter shall govern the
design, materials, construction and quality of roof assemblies,
and rooftop structures.
ROOF COVERING SYSTEM. See “Roof assembly.”
ROOF DECK. The flat or sloped surface not including its supporting members or vertical supports.
ROOF RECOVER. The process of installing an additional
roof covering over a prepared existing roof covering without
removing the existing roof covering.
SECTION 1502
DEFINITIONS
ROOF REPAIR. Reconstruction or renewal of any part of an
existing roof for the purposes of its maintenance.
1502.1 General. The following words and terms shall, for the
purposes of this chapter and as used elsewhere in this code,
have the meanings shown herein.
BUILT-UP ROOF COVERING. Two or more layers of felt
cemented together and surfaced with a cap sheet, mineral
aggregate, smooth coating or similar surfacing material.
INTERLAYMENT. A layer of felt or nonbituminous saturated felt not less than 18 inches (457 mm) wide, shingled
between each course of a wood-shake roof covering.
ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.
ROOF VENTILATION. The natural or mechanical process
of supplying conditioned or unconditioned air to, or removing
such air from, attics, cathedral ceilings or other enclosed spaces
over which a roof assembly is installed.
ROOFTOP STRUCTURE. An enclosed structure on or
above the roof of any part of a building.
MECHANICAL EQUIPMENT SCREEN. A partially
enclosed rooftop structure used to aesthetically conceal heating, ventilating and air conditioning (HVAC) electrical or
mechanical equipment from view.
SCUPPER. An opening in a wall or parapet that allows water
to drain from a roof.
METAL ROOF PANEL. An interlocking metal sheet having a
minimum installed weather exposure of 3 square feet (0.279 m2)
per sheet.
METAL ROOF SHINGLE. An interlocking metal sheet having an installed weather exposure less than 3 square feet (0.279
m2) per sheet.
SINGLE-PLY MEMBRANE. A roofing membrane that is
field applied using one layer of membrane material (either
homogeneous or composite) rather than multiple layers.
UNDERLAYMENT. One or more layers of felt, sheathing
paper, nonbituminous saturated felt or other approved material
over which a steep-slope roof covering is applied.
MODIFIED BITUMEN ROOF COVERING. One or more
layers of polymer-modified asphalt sheets. The sheet materials
shall be fully adhered or mechanically attached to the substrate
or held in place with an approved ballast layer.
PENTHOUSE. An enclosed, unoccupied structure above the
roof of a building, other than a tank, tower, spire, dome cupola
or bulkhead, occupying not more than one-third of the roof
area.
POSITIVE ROOF DRAINAGE. The drainage condition in
which consideration has been made for all loading deflections
of the roof deck, and additional slope has been provided to
ensure drainage of the roof within 48 hours of precipitation.
SECTION 1503
WEATHER PROTECTION
1503.1 General. Roof decks shall be covered with approved
roof coverings secured to the building or structure in accordance with the provisions of this chapter. Roof coverings shall
be designed, installed and maintained in accordance with this
code and the approved manufacturer’s instructions such that
the roof covering shall serve to protect the building or structure.
REROOFING. The process of recovering or replacing an
existing roof covering. See “Roof recover” and “Roof replacement.”
1503.2 Flashing. Flashing shall be installed in such a manner
so as to prevent moisture entering the wall and roof through
joints in copings, through moisture-permeable materials and at
intersections with parapet walls and other penetrations through
the roof plane.
ROOF ASSEMBLY. A system designed to provide weather
protection and resistance to design loads. The system consists
of a roof covering and roof deck or a single component serving
as both the roof covering and the roof deck. A roof assembly
includes the roof deck, vapor retarder, substrate or thermal barrier, insulation, vapor retarder and roof covering.
1503.2.1 Locations. Flashing shall be installed at wall and
roof intersections, at gutters, wherever there is a change in
roof slope or direction and around roof openings. Where
flashing is of metal, the metal shall be corrosion resistant
with a thickness of not less than 0.019 inch (0.483 mm) (No.
26 galvanized sheet).
2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:52:59 AM
263
1
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
TABLE 1504.2.1
ROOF COVERING CLASSIFICATION
USING ALTERNATIVE METHOD
1503.3 Coping. Parapet walls shall be properly coped with
noncombustible, weatherproof materials of a width no less
than the thickness of the parapet wall.
[P] 1503.4 Roof drainage. Design and installation of roof
drainage systems shall comply with the International Plumbing Code.
1503.4.1 Gutters. Gutters and leaders placed on the outside
of buildings, other than Group R-3, private garages and
buildings of Type V construction, shall be of
noncombustible material or a minimum of Schedule 40
plastic pipe.
Class D
120
Class G
150
Class H
1504.3.2 Metal panel roof systems. Metal panel roof systems through fastened or standing seam shall be tested in
accordance with UL 580 or ASTM E 1592.
1504.1 Wind resistance of roofs. Roof decks and roof coverings shall be designed for wind loads in accordance with Chapter 16 and Sections 1504.2, 1504.3 and 1504.4.
1504.2.1 Alternative test method. Testing the acceptability of special fastening methods using the methodology in
this section is permitted. The wind-induced uplift force on
the shingle shall be determined using the method in UL
2390. The resistance of the shingle to the uplift force shall
be determined using ASTM D 6381. Shingles passing this
test shall be considered suitable for roofs located where the
basic wind speed per Figure 1609 is as given in Table
1504.2.1.
90
1504.3.1 Other roof systems. Roof systems with built-up,
modified bitumen, fully adhered or mechanically attached
single-ply through fastened metal panel roof systems, and
other types of membrane roof coverings shall also be tested
in accordance with FM 4450, FM 4470, UL 580 or UL
1897.
SECTION 1504
PERFORMANCE REQUIREMENTS
1504.2 Wind resistance of clay and concrete tile. Clay and
concrete tile roof coverings shall be connected to the roof deck
in accordance with Chapter 16.
ASTM D 6381
CLASSIFICATION
For SI: 1 mile per hour = 0.447m/s.
1503.5 Roof ventilation. Intake and exhaust vents shall be provided in accordance with Section 1203.2 and the manufacturer’s installation instructions.
1504.1.1 Wind resistance of asphalt shingles. Asphalt
shingles shall be installed in accordance with Section
1507.2.7. For roofs located where the basic wind speed in
accordance with Figure 1609 is 110 mph or greater, asphalt
shingles shall be tested in accordance with ASTM D 3161,
Class F. As an alternative, load and wind resistance of
asphalt shingle roof coverings shall be determined in accordance with Section 1609.5.2.
MAXIMUM BASIC
WIND SPEED (mph)
Exception: Metal roofs constructed of cold-formed
steel, where the roof deck acts as the roof covering and
provides both weather protection and support for structural loads, shall be permitted to be designed and tested
in accordance with the applicable referenced structural
design standard in Section 2209.1.
1504.4 Ballasted low-slope roof systems. Ballasted low-slope
(roof slope < 2:12) single-ply roof system coverings installed
in accordance with Section 1507 shall be designed in accordance with Section 1504.8 and ANSI/SPRI RP-4.
1504.5 Edge securement for low-slope roofs. Low-slope
membrane roof system metal edge securement, except gutters,
shall be designed and installed for wind loads in accordance
with Chapter 16 and tested for resistance in accordance with
ANSI/SPRI ES-1, except the basic wind speed shall be determined from Figure 1609.
Classification requires that the resistance of the shingle to
wind uplift, measured using the method in ASTM D 6381,
exceed the calculated load imposed by wind in the applicable zone as determined using UL 2390.
1504.6 Physical properties. Roof coverings installed on
low-slope roofs (roof slope < 2:12) in accordance with Section
1507 shall demonstrate physical integrity over the working life
of the roof based upon 2,000 hours of exposure to accelerated
weathering tests conducted in accordance with ASTM G 152,
ASTM G 155 or ASTM G 154. Those roof coverings that are
subject to cyclical flexural response due to wind loads shall not
demonstrate any significant loss of tensile strength for
unreinforced membranes or breaking strength for reinforced
membranes when tested as herein required.
Classification by this method applies to buildings less
than 60 feet (18 288 mm) high and with Wind Exposures B
and C only in an Occupancy Category of I or II. Wrappers of
shingle bundles that have been qualified using this alternative method shall be labeled with the tested wind classification and reference UL 2390/ASTM D 6381.
1504.7 Impact resistance. Roof coverings installed on
low-slope roofs (roof slope < 2:12) in accordance with Section
1507 shall resist impact damage based on the results of tests
conducted in accordance with ASTM D 3746, ASTM D 4272,
CGSB 37-GP-52M or the “Resistance to Foot Traffic Test” in
Section 5.5 of FM 4470.
1504.3 Wind resistance of nonballasted roofs. Roof coverings installed on roofs in accordance with Section 1507 that are
mechanically attached or adhered to the roof deck shall be
designed to resist the design wind load pressures for cladding
in Chapter 16.
1504.8 Gravel and stone. Gravel or stone shall not be used on
the roof of a building located in a hurricane-prone region as
defined in Section 1609.2, or on any other building with a mean
roof height exceeding that permitted by Table 1504.8 based on
the exposure category and basic wind speed at the building site.
2006 INTERNATIONAL BUILDING CODE®
264
15_ibc_2006_pg264.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Thursday, January 05, 2006 12:52:31 PM
2
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
TABLE 1504.8
MAXIMUM ALLOWABLE MEAN ROOF HEIGHT PERMITTED FOR
BUILDINGS WITH GRAVEL OR STONE ON THE ROOF IN AREAS
OUTSIDE A HURRICANE-PRONE REGION
fied as Class A by an approved testing agency. Class A roof
assemblies shall be permitted for use in buildings or structures
of all types of construction.
Exception: Class A roof assemblies include those with coverings of brick, masonry, slate, clay or concrete roof tile,
exposed concrete roof deck, ferrous or copper shingles or
sheets.
MAXIMUM MEAN ROOF HEIGHT (ft)a,c
BASIC WIND SPEED
FROM FIGURE 1609
(mph)b
B
C
D
85
170
60
30
90
110
35
15
95
75
20
NP
100
55
15
NP
105
40
NP
NP
110
30
NP
NP
115
20
NP
NP
120
15
NP
NP
Greater than 120
NP
NP
NP
Exposure category
1505.3 Class B roof assemblies. Class B roof assemblies are
those that are effective against moderate fire-test exposure.
Class B roof assemblies and roof coverings shall be listed and
identified as Class B by an approved testing agency.
Exception: Class B roof assemblies include those with coverings of metal sheets and shingles.
1505.4 Class C roof assemblies. Class C roof assemblies are
those that are effective against light fire-test exposure. Class C
roof assemblies and roof coverings shall be listed and identified as Class C by an approved testing agency.
For SI: 1 foot = 304.8 mm; 1 mile per hour = 0.447 m/s.
a. Mean roof height in accordance with Section 1609.2.
b. For intermediate values of basic wind speed, the height associated with the
next higher value of wind speed shall be used, or direct interpolation is permitted.
c. NP = gravel and stone not permitted for any roof height.
SECTION 1505
FIRE CLASSIFICATION
1505.1 General. Roof assemblies shall be divided into the
classes defined below. Class A, B and C roof assemblies and
roof coverings required to be listed by this section shall be
tested in accordance with ASTM E 108 or UL 790. In addition,
fire-retardant-treated wood roof coverings shall be tested in
accordance with ASTM D 2898. The minimum roof coverings
installed on buildings shall comply with Table 1505.1 based on
the type of construction of the building.
TABLE 1505.1a,b
MINIMUM ROOF COVERING CLASSIFICATION
FOR TYPES OF CONSTRUCTION
IB
IIA
IIB
IIIA
IIIB
IV
VA
VB
B
B
B
Cc
B
Cc
B
B
Cc
SECTION 1506
MATERIALS
1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
For SI:
a. Unless otherwise required in accordance with the International
Wildland-Urban Interface Code or due to the location of the building within
a fire district in accordance with Appendix D.
b. Nonclassified roof coverings shall be permitted on buildings of Group R-3
and Group U occupancies, where there is a minimum fire-separation distance of 6 feet measured from the leading edge of the roof.
c. Buildings that are not more than two stories in height and having not more
than 6,000 square feet of projected roof area and where there is a minimum
10-foot fire-separation distance from the leading edge of the roof to a lot line
on all sides of the building, except for street fronts or public ways, shall be
permitted to have roofs of No. 1 cedar or redwood shakes and No. 1 shingles.
1505.2 Class A roof assemblies. Class A roof assemblies are
those that are effective against severe fire test exposure. Class
A roof assemblies and roof coverings shall be listed and identi2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006_pg_265.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Friday, January 13, 2006 11:10:21 AM
1505.6 Fire-retardant-treated wood shingles and shakes.
Fire-retardant-treated wood shakes and shingles shall be
treated by impregnation with chemicals by the full-cell vacuum-pressure process, in accordance with AWPA C1. Each
bundle shall be marked to identify the manufactured unit and
the manufacturer, and shall also be labeled to identify the classification of the material in accordance with the testing
required in Section 1505.1, the treating company and the quality control agency.
1505.7 Special purpose roofs. Special purpose wood shingle
or wood shake roofing shall conform with the grading and
application requirements of Section 1507.8 or 1507.9. In addition, an underlayment of 0.625-inch (15.9 mm) Type X
water-resistant gypsum backing board or gypsum sheathing
shall be placed under minimum nominal 0.5-inch-thick (12.7
mm) wood structural panel solid sheathing or 1-inch (25 mm)
nominal spaced sheathing.
Exception: Skylights and sloped glazing that comply with
Chapter 24 or Section 2610.
IA
1505.5 Nonclassified roofing. Nonclassified roofing is
approved material that is not listed as a Class A, B or C roof
covering.
1506.1 Scope. The requirements set forth in this section shall
apply to the application of roof-covering materials specified
herein. Roof coverings shall be applied in accordance with this
chapter and the manufacturer’s installation instructions. Installation of roof coverings shall comply with the applicable provisions of Section 1507.
1506.2 Compatibility of materials. Roofs and roof coverings
shall be of materials that are compatible with each other and
with the building or structure to which the materials are
applied.
1506.3 Material specifications and physical characteristics.
Roof-covering materials shall conform to the applicable standards listed in this chapter. In the absence of applicable standards or where materials are of questionable suitability, testing
265
3
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
by an approved agency shall be required by the building official
to determine the character, quality and limitations of application of the materials.
asphalt shingles shall be installed in accordance with the
manufacturer’s printed installation instructions for
steep-slope roof applications.
1506.4 Product identification. Roof-covering materials shall
be delivered in packages bearing the manufacturer’s identifying marks and approved testing agency labels required in
accordance with Section 1505. Bulk shipments of materials
shall be accompanied with the same information issued in the
form of a certificate or on a bill of lading by the manufacturer.
1507.2.8 Underlayment application. For roof slopes from
two units vertical in 12 units horizontal (17-percent slope)
and up to four units vertical in 12 units horizontal (33-percent slope), underlayment shall be two layers applied in the
following manner. Apply a minimum 19-inch-wide (483
mm) strip of underlayment felt parallel with and starting at
the eaves, fastened sufficiently to hold in place. Starting at
the eave, apply 36-inch-wide (914 mm) sheets of
underlayment overlapping successive sheets 19 inches (483
mm), by fastened sufficiently to hold in place. Distortions in
the underlayment shall not interfere with the ability of the
shingles to seal. For roof slopes of four units vertical in 12
units horizontal (33-percent slope) or greater, underlayment
shall be one layer applied in the following manner.
Underlayment shall be applied shingle fashion, parallel to
and starting from the eave and lapped 2 inches (51 mm), fastened sufficiently to hold in place. Distortions in the
underlayment shall not interfere with the ability of the shingles to seal.
SECTION 1507
REQUIREMENTS FOR ROOF COVERINGS
1507.1 Scope. Roof coverings shall be applied in accordance
with the applicable provisions of this section and the manufacturer’s installation instructions.
➡
1507.2 Asphalt shingles. The installation of asphalt shingles
shall comply with the provisions of this section.
1507.2.1 Deck requirements. Asphalt shingles shall be fastened to solidly sheathed decks.
1507.2.2 Slope. Asphalt shingles shall only be used on roof
slopes of two units vertical in 12 units horizontal (17-percent slope) or greater. For roof slopes from two units vertical
in 12 units horizontal (17-percent slope) up to four units vertical in 12 units horizontal (33-percent slope), double
underlayment application is required in accordance with
Section 1507.2.8.
1507.2.8.1 High wind attachment. Underlayment
applied in areas subject to high winds (greater than 110
mph in accordance with Figure 1609) shall be applied
with corrosion- resistant fasteners in accordance with the
manufacturer’s instructions. Fasteners are to be applied
along the overlap at a maximum spacing of 36 inches
(914 mm) on center.
1507.2.3 Underlayment. Unless otherwise noted, required
underlayment shall conform to ASTM D 226, Type I,
ASTM D 4869, Type I, or ASTM D 6757.
1507.2.8.2 Ice dam membrane. In areas where there has
been a history of ice forming along the eaves causing a
backup of water, a membrane that consists of at least two
layers of underlayment cemented together or of a
self-adhering polymer modified bitumen sheet shall be
used in lieu of normal underlayment and extend from the
eave’s edge to a point at least 24 inches (610 mm) inside
the exterior wall line of the building.
1507.2.4 Self-adhering polymer modified bitumen sheet.
Self-adhering polymer modified bitumen sheet shall comply with ASTM D 1970.
1507.2.5 Asphalt shingles. Asphalt shingles shall have
self-seal strips or be interlocking and comply with ASTM D
225 or ASTM D 3462. Asphalt shingle packaging shall bear
labeling indicating compliance with ASTM D 3161 or a listing by an approved testing agency in accordance with the
requirements of Section 1609.5.2.
Exception: Detached accessory structures that contain no conditioned floor area.
1507.2.9 Flashings. Flashing for asphalt shingles shall
comply with this section. Flashing shall be applied in accordance with this section and the asphalt shingle manufacturer’s printed instructions.
1507.2.6 Fasteners. Fasteners for asphalt shingles shall be
galvanized, stainless steel, aluminum or copper roofing
nails, minimum 12 gage [0.105 inch (2.67 mm)] shank with
a minimum 0.375 inch-diameter (9.5 mm) head, of a length
to penetrate through the roofing materials and a minimum of
0.75 inch (19.1 mm) into the roof sheathing. Where the roof
sheathing is less than 0.75 inch (19.1 mm) thick, the nails
shall penetrate through the sheathing. Fasteners shall comply with ASTM F 1667.
1507.2.9.1 Base and cap flashing. Base and cap flashing shall be installed in accordance with the manufacturer’s instructions. Base flashing shall be of either
corrosion-resistant metal of minimum nominal
0.019-inch (0.483 mm) thickness or mineral-surfaced
roll roofing weighing a minimum of 77 pounds per 100
square feet (3.76 kg/m2). Cap flashing shall be corrosion-resistant metal of minimum nominal 0.019-inch
(0.483 mm) thickness.
1507.2.7 Attachment. Asphalt shingles shall have the minimum number of fasteners required by the manufacturer and
Section 1504.1. Asphalt shingles shall be secured to the roof
with not less than four fasteners per strip shingle or two fasteners per individual shingle. Where the roof slope exceeds
20 units vertical in 12 units horizontal (166-percent slope),
1507.2.9.2 Valleys. Valley linings shall be installed in
accordance with the manufacturer’s instructions before
2006 INTERNATIONAL BUILDING CODE®
266
15_ibc_2006_pg266.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Thursday, January 05, 2006 12:58:12 PM
4
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
applying shingles. Valley linings of the following types
shall be permitted:
1507.3.1 Deck requirements. Concrete and clay tile shall
be installed only over solid sheathing or spaced structural
sheathing boards.
1. For open valleys (valley lining exposed) lined with
metal, the valley lining shall be at least 16 inches
(406 mm) wide and of any of the corrosion-resistant metals in Table 1507.2.9.2.
1507.3.2 Deck slope. Clay and concrete roof tile shall be
installed on roof slopes of 21/2 units vertical in 12 units horizontal (21-percent slope) or greater. For roof slopes from
21/2 units vertical in 12 units horizontal (21-percent slope) to
four units vertical in 12 units horizontal (33-percent slope),
double underlayment application is required in accordance
with Section 1507.3.3.
2. For open valleys, valley lining of two plies of mineral-surfaced roll roofing complying with ASTM
D 3909 or ASTM D 6380 shall be permitted. The
bottom layer shall be 18 inches (457 mm) and the
top layer a minimum of 36 inches (914 mm) wide.
3. For closed valleys (valleys covered with shingles),
valley lining of one ply of smooth roll roofing
complying with ASTM D 6380, Class S Type III,
Class M Type II or ASTM D 3909 and at least 36
inches (914 mm) wide or types as described in
Items 1 and 2 above shall be permitted. Specialty
underlayment shall comply with ASTM D 1970.
1507.2.9.3 Drip edge. Provide drip edge at eaves and
gables of shingle roofs. Overlap to be a minimum of 2
inches (51 mm). Eave drip edges shall extend 0.25 inch
(6.4 mm) below sheathing and extend back on the roof a
minimum of 2 inches (51 mm). Drip edge shall be
mechanically fastened a maximum of 12 inches (305
mm) o.c.
1507.3.3 Underlayment. Unless otherwise noted, required
underlayment shall conform to: ASTM D 226, Type II;
ASTM D 2626 or ASTM D 6380, Class M mineral-surfaced
roll roofing.
1507.3.3.1 Low-slope roofs. For roof slopes from 21/2
units vertical in 12 units horizontal (21-percent slope),
up to four units vertical in 12 units horizontal (33-percent
slope), underlayment shall be a minimum of two layers
applied as follows:
1. Starting at the eave, a 19-inch (483 mm) strip of
underlayment shall be applied parallel with the
eave and fastened sufficiently in place.
2. Starting at the eave, 36-inch-wide (914 mm) strips
of underlayment felt shall be applied overlapping
successive sheets 19 inches (483 mm) and fastened sufficiently in place.
1507.2.9.4 Crickets and saddles. A cricket or saddle
shall be installed on the ridge side of any chimney or penetration greater than 30 inches (762 mm) wide as measured perpendicular to the slope. Cricket or saddle
coverings shall be sheet metal or of the same material as
the roof covering.
1507.3.3.2 High-slope roofs. For roof slopes of four
units vertical in 12 units horizontal (33-percent slope) or
greater, underlayment shall be a minimum of one layer of
underlayment felt applied shingle fashion, parallel to,
and starting from the eaves and lapped 2 inches (51 mm),
fastened only as necessary to hold in place.
1507.3 Clay and concrete tile. The installation of clay and
concrete tile shall comply with the provisions of this section.
1507.3.4 Clay tile. Clay roof tile shall comply with ASTM
C 1167.
TABLE 1507.2.9.2
VALLEY LINING MATERIAL
MATERIAL
MINIMUM THICKNESS
GAGE
WEIGHT
Aluminum
0.024 in.
—
—
Cold-rolled copper
0.0216 in.
—
ASTM B 370, 16 oz. per square ft.
—
—
16 oz
Galvanized steel
0.0179 in.
26 (zinc-coated G90)
—
High-yield copper
0.0162 in.
—
ASTM B 370, 12 oz. per square ft.
—
—
2.5 pounds
Lead-coated copper
0.0216 in.
—
ASTM B 101, 16 oz. per square ft.
Lead-coated high-yield copper
0.0162 in.
—
ASTM B 101, 12 oz. per square ft.
Painted terne
—
—
20 pounds
Stainless steel
—
28
—
0.027 in.
—
—
Copper
Lead
Zinc alloy
For SI: 1 inch = 25.4 mm, 1 pound = 0.454 kg, 1 ounce = 28.35 g.
2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006_pg267.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Monday, December 19, 2005 11:00:43 AM
267
5
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
➡
2. The minimum slope for lapped, nonsoldered seam
metal roofs with applied lap sealant shall be one-half
unit vertical in 12 units horizontal (4-percent slope).
Lap sealants shall be applied in accordance with the
approved manufacturer’s installation instructions.
1507.3.5 Concrete tile. Concrete roof tile shall comply
with ASTM C 1492.
1507.3.6 Fasteners. Tile fasteners shall be corrosion resistant and not less than 11 gage, 5/16-inch (8.0 mm) head, and
of sufficient length to penetrate the deck a minimum of 0.75
inch (19.1 mm) or through the thickness of the deck, whichever is less. Attaching wire for clay or concrete tile shall not
be smaller than 0.083 inch (2.1 mm). Perimeter fastening
areas include three tile courses but not less than 36 inches
(914 mm) from either side of hips or ridges and edges of
eaves and gable rakes.
3. The minimum slope for standing seam of roof systems shall be one-quarter unit vertical in 12 units horizontal (2-percent slope).
1507.4.3 Material standards. Metal-sheet roof covering
systems that incorporate supporting structural members
shall be designed in accordance with Chapter 22.
Metal-sheet roof coverings installed over structural decking
shall comply with Table 1507.4.3.(1). The materials used
for metal-sheet roof coverings shall be naturally corrosion
resistant or provided with corrosion resistance in accordance with the standards and minimum thicknesses shown
in Table 1507.4.3(2).
1507.3.7 Attachment. Clay and concrete roof tiles shall be
fastened in accordance with Table 1507.3.7.
1507.3.8 Application. Tile shall be applied according to the
manufacturer’s installation instructions, based on the following:
1. Climatic conditions.
1507.4.4 Attachment. Metal roof panels shall be secured to
the supports in accordance with the approved manufacturer’s fasteners. In the absence of manufacturer recommendations, the following fasteners shall be used:
2. Roof slope.
3. Underlayment system.
4. Type of tile being installed.
1507.3.9 Flashing. At the juncture of the roof vertical surfaces, flashing and counterflashing shall be provided in
accordance with the manufacturer’s installation instructions, and where of metal, shall not be less than 0.019-inch
(0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal. The valley flashing shall extend at least 11 inches
(279 mm) from the centerline each way and have a splash
diverter rib not less than 1 inch (25 mm) high at the flow line
formed as part of the flashing. Sections of flashing shall
have an end lap of not less than 4 inches (102 mm). For roof
slopes of three units vertical in 12 units horizontal (25-percent slope) and over, the valley flashing shall have a
36-inch-wide (914 mm) underlayment of either one layer of
Type I underlayment running the full length of the valley, or
a self-adhering polymer-modified bitumen sheet complying
with ASTM D 1970, in addition to other required
underlayment. In areas where the average daily temperature
in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water,
the metal valley flashing underlayment shall be solid
cemented to the roofing underlayment for slopes under
seven units vertical in 12 units horizontal (58-percent slope)
or self-adhering polymer-modified bitumen sheet shall be
installed.
1. Galvanized fasteners shall be used for steel roofs.
2. 300 series stainless-steel fasteners shall be used for
copper roofs.
3. Stainless-steel fasteners are acceptable for all types of
metal roofs.
1507.5 Metal roof shingles. The installation of metal roof
shingles shall comply with the provisions of this section.
1507.5.1 Deck requirements. Metal roof shingles shall be
applied to a solid or closely fitted deck, except where the
roof covering is specifically designed to be applied to
spaced sheathing.
1507.5.2 Deck slope. Metal roof shingles shall not be
installed on roof slopes below three units vertical in 12 units
horizontal (25-percent slope).
1507.5.3 Underlayment. Underlayment shall comply with
ASTM D 226, Type I or ASTM D 4869. In areas where there
has been a history of ice forming along the eaves causing a
backup of water, an ice barrier that consists of at least two
layers of underlayment cemented together or of a
self-adhering polymer-modified bitumen sheet shall be
used in lieu of normal underlayment and extend from the
eave’s edge to a point at least 24 inches (610 mm) inside the
exterior wall line of the building.
1507.4 Metal roof panels. The installation of metal roof panels shall comply with the provisions of this section.
Exception: Detached accessory structures that contain
no conditioned floor area.
1507.4.1 Deck requirements. Metal roof panel roof coverings shall be applied to a solid or closely fitted deck, except
where the roof covering is specifically designed to be
applied to spaced supports.
1507.5.4 Material standards. Metal roof shingle roof coverings shall comply with Table 1507.4.3(1). The materials
used for metal-roof shingle roof coverings shall be naturally
corrosion resistant or provided with corrosion resistance in
accordance with the standards and minimum thicknesses
specified in the standards listed in Table 1507.4.3(2).
1507.4.2 Deck slope. Minimum slopes for metal roof panels
shall comply with the following:
1. The minimum slope for lapped, nonsoldered seam
metal roofs without applied lap sealant shall be three
units vertical in 12 units horizontal (25-percent
slope).
1507.5.5 Attachment. Metal roof shingles shall be secured
to the roof in accordance with the approved manufacturer’s
installation instructions.
2006 INTERNATIONAL BUILDING CODE®
268
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:00 AM
6
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
TABLE 1507.3.7
CLAY AND CONCRETE TILE ATTACHMENTa, b, c
GENERAL — CLAY OR CONCRETE ROOF TILE
Maximum basic
wind speed
(mph)
Mean roof
height
(feet)
85
0-60
100
0-40
100
> 40-60
The head of all tiles shall be nailed. The nose of all eave tiles shall be fastened with approved
clips. All rake tiles shall be nailed with two nails. The nose of all ridge, hip and rake tiles shall be
set in a bead of roofer’s mastic.
110
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
120
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
130
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
> 60
The fastening system shall resist the wind forces in Section 1609.5.2.
All
Roof slope up to
3:12
One fastener per tile. Flat tile
without vertical laps, two
fasteners per tile.
Roof slope 3:12 and over
Two fasteners per tile. Only one fastener on slopes of 7:12 and
less for tiles with installed weight exceeding 7.5 lbs./sq. ft.
having a width no greater than 16 inches.
INTERLOCKING CLAY OR CONCRETE ROOF TILE WITH PROJECTING ANCHOR LUGSd, e
(Installations on spaced/solid sheathing with battens or spaced sheathing)
Maximum basic
wind speed
(mph)
Mean roof
height
(feet)
85
0-60
100
0-40
100
> 40-60
The head of all tiles shall be nailed. The nose of all eave tiles shall be fastened with approved
clips. All rake tiles shall be nailed with two nails The nose of all ridge, hip and rake tiles shall be
set in a bead of roofers’s mastic.
110
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
120
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
130
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
All
> 60
The fastening system shall resist the wind forces in Section 1609.5.2.
Roof slope up to
5:12
Roof slope 5:12
12:12
One fastener per tile every other
Fasteners are not required. Tiles row. All perimeter tiles require
with installed weight less than 9 one fastener. Tiles with installed
lbs./sq. ft. require a minimum of weight less than 9 lbs./sq. ft.
require a minimum of one
one fastener per tile.
fastener per tile.
Roof slope 12:12 and over
One fastener required for
every tile. Tiles with installed
weight less than 9 lbs./sq. ft.
require a minimum of one
fastener per tile.
INTERLOCKING CLAY OR CONCRETE ROOF TILE WITH PROJECTING ANCHOR LUGS
(Installations on solid sheathing without battens)
Maximum basic
wind speed
(mph)
Mean roof
height
(feet)
85
0-60
100
0-40
One fastener per tile.
100
> 40-60
The head of all tiles shall be nailed. The nose of all eave tiles shall be fastened with approved
clips. All rake tiles shall be nailed with two nails The nose of all ridge, hip and rake tiles shall be
set in a bead of roofer’s mastic.
110
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
120
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
130
0-60
The fastening system shall resist the wind forces in Section 1609.5.2.
All
> 60
The fastening system shall resist the wind forces in Section 1609.5.2.
All roof slopes
One fastener per tile.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 4.882 k g / m 2 .
a. Minimum fastener size. Corrosion-resistant nails not less than No. 11 gage with 5/16-inch head. Fasteners shall be long enough to penetrate into the sheathing 0.75
inch or through the thickness of the sheathing, whichever is less. Attaching wire for clay and concrete tile shall not be smaller than 0.083 inch.
b. Snow areas. A minimum of two fasteners per tile are required or battens and one fastener.
c. Roof slopes greater than 24:12. The nose of all tiles shall be securely fastened.
d. Horizontal battens. Battens shall be not less than 1inch by 2 inch nominal. Provisions shall be made for drainage by a minimum of 1/8-inch riser at each nail or by
4-foot-long battens with at least a 0.5-inch separation between battens. Horizontal battens are required for slopes over 7:12.
e. Perimeter fastening areas include three tile courses but not less than 36 inches from either side of hips or ridges and edges of eaves and gable rakes.
2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:01 AM
269
7
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
TABLE 1507.4.3(1)
METAL ROOF COVERINGS
ROOF COVERING TYPE
1507.5.6 Flashing. Roof valley flashing shall be of corrosion-resistant metal of the same material as the roof covering or shall comply with the standards in Table 1507.4.3(1).
The valley flashing shall extend at least 8 inches (203 mm)
from the centerline each way and shall have a splash diverter
rib not less than 0.75 inch (19.1 mm) high at the flow line
formed as part of the flashing. Sections of flashing shall
have an end lap of not less than 4 inches (102 mm). In areas
where the average daily temperature in January is 25°F
(-4°C) or less or where there is a possibility of ice forming
along the eaves causing a backup of water, the metal valley
flashing shall have a 36-inch-wide (914 mm) underlayment
directly under it consisting of either one layer of
underlayment running the full length of the valley or a
self-adhering polymer-modified bitumen sheet complying
with ASTM D 1970, in addition to underlayment required
for metal roof shingles. The metal valley flashing
underlayment shall be solidly cemented to the roofing
underlayment for roof slopes under seven units vertical in
12 units horizontal (58-percent slope) or self-adhering polymer-modified bitumen sheet shall be installed.
STANDARD APPLICATION
RATE/THICKNESS
ASTM B 209, 0.024 inch minimum
thickness for roll-formed panels and 0.019
inch minimum thickness for press-formed
shingles.
Aluminum
Aluminum-zinc alloy
ASTM A 792 AZ 50
coated steel
Cold-rolled copper
ASTM B 370 minimum 16 oz/sq. ft. and
12 oz./sq. ft. high yield copper for
metal-sheet roof covering systems: 12
oz/sq. ft. for preformed metal shingle
systems.
Copper
16 oz./sq. ft. for metal-sheet roof-covering
systems; 12 oz./sq. ft. for preformed metal
shingle systems.
Galvanized steel
ASTM A 653 G-90 zinc-coateda.
Hard lead
2 lbs./sq. ft.
Lead-coated copper
ASTM B 101
Prepainted steel
ASTM A 755
Soft lead
3 lbs./sq. ft.
Stainless steel
ASTM A 240, 300 Series Alloys
Steel
ASTM A 924
1507.6 Mineral-surfaced roll roofing. The installation of
mineral-surfaced roll roofing shall comply with this section.
1507.6.1 Deck requirements. Mineral-surfaced roll roofing shall be fastened to solidly sheathed roofs.
1507.6.2 Deck slope. Mineral-surfaced roll roofing shall
not be applied on roof slopes below one unit vertical in 12
units horizontal (8-percent slope).
1507.6.3 Underlayment. Underlayment shall comply with
ASTM D 226, Type I or ASTM D 4869. In areas where there
has been a history of ice forming along the eaves causing a
backup of water, an ice barrier that consists of at least two
layers of underlayment cemented together or of a
self-adhering polymer-modified bitumen sheet shall be
used in lieu of normal underlayment and extend from the
eave’s edge to a point at least 24 inches (610 mm) inside the
exterior wall line of the building.
Terne coating of 40 lbs. per double base
box, field painted where applicable in
Terne and
terne-coated stainless accordance with manufacturer’s
installation instructions.
0.027 inch minimum thickness; 99.995%
electrolytic high grade zinc with alloy
additives of copper (0.08% - 0.20%),
titanium (0.07% - 0.12%) and aluminum
(0.015%).
Zinc
For SI: 1 ounce per square foot = 0.0026 kg/m2,
1 pound per square foot = 4.882 kg/m2,
1 inch = 25.4 mm, 1 pound = 0.454 kg.
a. For Group U buildings, the minimum coating thickness for ASTM A 653
galvanized steel roofing shall be G.
Exception: Detached accessory structures that contain
no conditioned floor area.
1507.6.4 Material standards. Mineral-surfaced roll roofing shall conform to ASTM D 3909 or ASTM D 6380.
1507.7 Slate shingles. The installation of slate shingles shall
comply with the provisions of this section.
TABLE 1507.4.3(2)
MINIMUM CORROSION RESISTANCE
1507.7.1 Deck requirements. Slate shingles shall be fastened to solidly sheathed roofs.
55% Aluminum-Zinc Alloy Coated
ASTM A 792 AZ 50
Steel
5% Aluminum Alloy-coated steel
ASTM A875 GF60
Aluminum-coated steel
ASTM A463 T2 65
Galvanized Steel
ASTM A 653 G-90
Prepainted Steel
ASTM A 755a
1507.7.2 Deck slope. Slate shingles shall only be used on
slopes of four units vertical in 12 units horizontal (4:12) or
greater.
1507.7.3 Underlayment. Underlayment shall comply with
ASTM D 226, Type I or ASTM D 4869. In areas where the
average daily temperature in January is 25°F (-4°C) or less
or where there is a possibility of ice forming along the eaves
causing a backup of water, an ice barrier that consists of at
least two layers of underlayment cemented together or of a
self-adhering polymer-modified bitumen sheet shall extend
a. Paint systems in accordance with ASTM A 755 shall be applied over steel
products with corrosion resistant coatings complying with ASTM A 792,
ASTM A 875, ASTM A 463, or ASTM A 653.
2006 INTERNATIONAL BUILDING CODE®
270
15_ibc_2006_pg270.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Thursday, January 05, 2006 1:00:38 PM
8
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
from the eave’s edge to a point at least 24 inches (610 mm)
inside the exterior wall line of the building.
1507.8.4 Material standards. Wood shingles shall be of
naturally durable wood and comply with the requirements
of Table 1507.8.4.
Exception: Detached accessory structures that contain
no conditioned floor area.
TABLE 1507.8.4
WOOD SHINGLE MATERIAL REQUIREMENTS
1507.7.4 Material standards. Slate shingles shall comply
with ASTM C 406.
MATERIAL
4:12 < slope < 8:12
4
8:12 < slope < 20:12
3
slope ≥ 20:12
2
CSSB
1507.8.5 Attachment. Fasteners for wood shingles shall be
corrosion resistant with a minimum penetration of 0.75 inch
(19.1 mm) into the sheathing. For sheathing less than 0.5
inch (12.7 mm) in thickness, the fasteners shall extend
through the sheathing. Each shingle shall be attached with a
minimum of two fasteners.
For SI: 1 inch = 25.4 mm.
1507.7.6 Flashing. Flashing and counterflashing shall be
made with sheet metal. Valley flashing shall be a minimum
of 15 inches (381 mm) wide. Valley and flashing metal shall
be a minimum uncoated thickness of 0.0179-inch (0.455
mm) zinc-coated G90. Chimneys, stucco or brick walls
shall have a minimum of two plies of felt for a cap flashing
consisting of a 4-inch-wide (102 mm) strip of felt set in plastic cement and extending 1 inch (25 mm) above the first felt
and a top coating of plastic cement. The felt shall extend
over the base flashing 2 inches (51 mm).
1507.8 Wood shingles. The installation of wood shingles shall
comply with the provisions of this section and Table 1507.8.
1507.8.1 Deck requirements. Wood shingles shall be
installed on solid or spaced sheathing. Where spaced
sheathing is used, sheathing boards shall not be less than
1-inch by 4-inch (25 mm by 102 mm) nominal dimensions
and shall be spaced on centers equal to the weather exposure
to coincide with the placement of fasteners.
1507.8.6 Application. Wood shingles shall be laid with a
side lap not less than 1.5 inches (38 mm) between joints in
adjacent courses, and not be in direct alignment in alternate
courses. Spacing between shingles shall be 0.25 to 0.375
inches (6.4 to 9.5 mm). Weather exposure for wood shingles
shall not exceed that set in Table 1507.8.6.
TABLE 1507.8.6
WOOD SHINGLE WEATHER EXPOSURE AND ROOF SLOPE
EXPOSURE (inches)
ROOFING MATERIAL
LENGTH
(inches)
Shingles of naturally
durable wood
GRADE
3:12 pitch
to < 4:12
4:12 pitch
or steeper
16
No. 1
No. 2
No. 3
3.75
3.5
3
5
4
3.5
18
No. 1
No. 2
No. 3
4.25
4
3.5
5.5
4.5
4
24
No. 1
No. 2
No. 3
5.75
5.5
5
7.5
6.5
5.5
For SI: 1 inch = 25.4 mm.
1507.8.1.1 Solid sheathing required. Solid sheathing is
required in areas where the average daily temperature in
January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of
water.
1507.8.2 Deck slope. Wood shingles shall be installed on
slopes of three units vertical in 12 units horizontal (25-percent slope) or greater.
1507.8.3 Underlayment. Underlayment shall comply with
ASTM D 226, Type I or ASTM D 4869. In areas where there
has been a history of ice forming along the eaves causing a
backup of water, an ice barrier that consists of at least two
layers of underlayment cemented together or of a
self-adhering polymer-modified bitumen sheet shall be
used in lieu of normal underlayment and extend from the
eave’s edge to a point at least 24 inches (610 mm) inside the
exterior wall line of the building.
Exception: Detached accessory structures that contain
no conditioned floor area.
2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:01 AM
1, 2 or 3
CSSB = Cedar Shake and Shingle Bureau
TABLE 1507.7.5
SLATE SHINGLE HEADLAP
HEADLAP
(inches)
GRADING RULES
Wood shingles of naturally
durable wood
1507.7.5 Application. Minimum headlap for slate shingles
shall be in accordance with Table 1507.7.5. Slate shingles
shall be secured to the roof with two fasteners per slate.
SLOPE
APPLICABLE
MINIMUM GRADES
1507.8.7 Flashing. At the juncture of the roof and vertical surfaces, flashing and counterflashing shall be provided in accordance with the manufacturer’s installation instructions, and
where of metal, shall not be less than 0.019-inch (0.48 mm) (No.
26 galvanized sheet gage) corrosion-resistant metal. The valley
flashing shall extend at least 11 inches (279 mm) from the centerline each way and have a splash diverter rib not less than 1
inch (25 mm) high at the flow line formed as part of the flashing.
Sections of flashing shall have an end lap of not less than 4
inches (102 mm). For roof slopes of three units vertical in 12
units horizontal (25-percent slope) and over, the valley flashing shall have a 36-inch-wide (914 mm) underlayment of
either one layer of Type I underlayment running the full
length of the valley or a self-adhering polymer-modified bitumen sheet complying with ASTM D 1970, in addition to
other required underlayment. In areas where the average
daily temperature in January is 25°F (-4°C) or less or where
there is a possibility of ice forming along the eaves causing a
backup of water, the metal valley flashing underlayment shall
be solidly cemented to the roofing underlayment for slopes
under seven units vertical in 12 units horizontal (58-percent
271
9
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
used, sheathing boards shall not be less than 1-inch by 4-inch
(25 mm by 102 mm) nominal dimensions and shall be spaced
on centers equal to the weather exposure to coincide with the
placement of fasteners. Where 1-inch by 4-inch (25 mm by
102 mm) spaced sheathing is installed at 10 inches (254 mm)
o.c., additional 1-inch by 4-inch (25 mm by 102 mm) boards
shall be installed between the sheathing boards.
slope) or self-adhering polymer-modified bitumen sheet
shall be installed.
1507.9 Wood shakes. The installation of wood shakes shall
comply with the provisions of this section and Table 1507.8.
1507.9.1 Deck requirements. Wood shakes shall only be
used on solid or spaced sheathing. Where spaced sheathing is
TABLE 1507.8
WOOD SHINGLE AND SHAKE INSTALLATION
ROOF ITEM
1. Roof slope
WOOD SHINGLES
Wood shingles shall be installed on slopes of
Wood shakes shall be installed on slopes of four units
three units vertical in 12 units horizontal
vertical in 12 units horizontal (4:12) or greater.
(3:12) or greater.
2. Deck requirement
Temperate climate
WOOD SHAKES
—
—
Shakes shall be applied to roofs with solid or spaced
Shingles shall be applied to roofs with solid
sheathing.Where spaced sheathing is used, sheathing
or spaced sheathing. Where spaced sheathing
boards shall not be less than 1″ × 4″ nominal
is used, sheathing boards shall not be less
dimensions and shall be spaced on center equal to the
than 1″ × 4″ nominal dimensions and shall
weather exposure to coincide with the placement of
be spaced on center equal to the weather
fasteners. When 1″ × 4″ spaced sheathing is installed at
exposure to coincide with the placement of
10 inches, boards must be installed between the
fasteners.
sheathing boards.
Solid sheathing required.
In areas where the average daily
temperature in January is 25°F or
less or where there is a possibility of
ice forming along the eaves causing
a backup of water.
Solid sheathing is required.
3. Interlayment
Interlayment shall comply with ASTM D 226, Type 1.
No requirements.
4. Underlayment
—
—
Temperate climate
Underlayment shall comply with ASTM D
226, Type 1.
Underlayment shall comply with ASTM D 226, Type 1.
In areas where there is a possibility
of ice forming along the eaves
causing a backup of water.
An ice shield that consists of at least two
An ice shield that consists of at least two layers of
layers of underlayment cemented together or
underlayment cemented together or of a self-adhering
of a self-adhering polymer-modified bitumen
polymer-modified bitumen sheet shall extend from the
sheet shall extend from the eave’s edge to a
eave’s edge to a point at least 24 inches inside the
point at least 24 inches inside the exterior
exterior wall line of the building.
wall line of the building.
5. Application
—
—
Attachment
Fasteners for wood shingles shall be
corrosion resistant with a minimum
penetration of 0.75 inch into the sheathing.
For sheathing less than 0.5 inch thick, the
fasteners shall extend through the sheathing.
Fasteners for wood shakes shall be corrosion resistant
with a minimum penetration of 0.75 inch into the
sheathing. For sheathing less than 0.5 inch thick, the
fasteners shall extend through the sheathing.
No. of fasteners
Two per shingle.
Two per shake.
Exposure
Weather exposures shall not exceed those set Weather exposures shall not exceed those set forth in
forth in Table 1507.8.6
Table 1507.9.7
Method
Shingles shall be laid with a side lap of not Shakes shall be laid with a side lap of not less than 1.5
inches between joints in adjacent courses. Spacing
less than 1.5 inches between joints in
between shakes shall not be less than 0.375 inch or
courses, and no two joints in any three
adjacent courses shall be in direct alignment. more than 0.625 inch for shakes and tapersawn shakes
of naturally durable wood and shall be 0.25 to 0.375
Spacing between shingles shall be 0.25 to
inch for preservative taper sawn shakes.
0.375 inch.
Flashing
In accordance with Section 1507.8.7.
In accordance with Section 1507.9.8.
For SI: 1 inch = 25.4 mm, °C = [(°F) - 32]/1.8.
2006 INTERNATIONAL BUILDING CODE®
272
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:01 AM
10
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
1507.9.1.1 Solid sheathing required. Solid sheathing is
required in areas where the average daily temperature in
January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of
water.
TABLE 1507.9.7
WOOD SHAKE WEATHER EXPOSURE AND ROOF SLOPE
ROOFING MATERIAL
1507.9.2 Deck slope. Wood shakes shall only be used on
slopes of four units vertical in 12 units horizontal (33-percent slope) or greater.
Shakes of naturally
durable wood
1507.9.3 Underlayment. Underlayment shall comply with
ASTM D 226, Type I or ASTM D 4869. In areas where there
has been a history of ice forming along the eaves causing a
backup of water, an ice barrier that consists of at least two
layers of underlayment cemented together or of a
self-adhering polymer-modified bitumen sheet shall be
used in lieu of normal underlayment and extend from the
eave’s edge to a point at least 24 inches (610 mm) inside the
exterior wall line of the building.
Preservative-treated taper
sawn shakes of Southern
yellow pine
Exception: Detached accessory structures that contain
no conditioned floor area.
1507.9.5 Material standards. Wood shakes shall comply
with the requirements of Table 1507.9.5.
TABLE 1507.9.5
WOOD SHAKE MATERIAL REQUIREMENTS
MATERIAL
APPLICABL
E GRADING
RULES
Wood shakes of naturally durable wood
1
CSSB
Taper sawn shakes of naturally durable
wood
1 or 2
CSSB
Preservative-treated shakes and shingles
of naturally durable wood
1
CSSB
Fire-retardant-treated shakes and
shingles of naturally durable wood
1
CSSB
1 or 2
TFS
Preservative-treated taper sawn shakes
of Southern pine treated in accordance
with AWPA U1 (Commodity
Specification A, Use Category 3B and
Section 5.6)
CSSB = Cedar Shake and Shingle Bureau.
TFS = Forest Products Laboratory of the Texas Forest Services.
1507.9.6 Attachment. Fasteners for wood shakes shall be
corrosion resistant with a minimum penetration of 0.75 inch
(19.1 mm) into the sheathing. For sheathing less than 0.5
inch (12.7 mm) in thickness, the fasteners shall extend
through the sheathing. Each shake shall be attached with a
minimum of two fasteners.
1507.9.7 Application. Wood shakes shall be laid with a side
lap not less than 1.5 inches (38 mm) between joints in adjacent courses. Spacing between shakes in the same course
shall be 0.375 to 0.625 inches (9.5 to 15.9 mm) for shakes
and taper sawn shakes of naturally durable wood and shall
be 0.25 to 0.375 inch (6.4 to 9.5 mm) for preservative taper
sawn shakes. Weather exposure for wood shakes shall not
exceed those set in Table 1507.9.7.
2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:02 AM
GRADE
18
24
No. 1
No. 1
7.5
10a
18
24
No. 1
No. 1
7.5
10
18
24
No. 2
No. 2
5.5
7.5
18
24
No. 1
No. 1
7.5
10
18
24
No. 2
No. 2
5.5
7.5
For SI: 1 inch = 25.4 mm.
a. For 24-inch by 0.375-inch handsplit shakes, the maximum exposure is 7.5
inches.
1507.9.8 Flashing. At the juncture of the roof and vertical
surfaces, flashing and counterflashing shall be provided in
accordance with the manufacturer’s installation instructions, and where of metal, shall not be less than 0.019-inch
(0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal. The valley flashing shall extend at least 11 inches
(279 mm) from the centerline each way and have a splash
diverter rib not less than 1 inch (25 mm) high at the flow line
formed as part of the flashing. Sections of flashing shall
have an end lap of not less than 4 inches (102 mm). For roof
slopes of three units vertical in 12 units horizontal (25-percent slope) and over, the valley flashing shall have a
36-inch-wide (914 mm) underlayment of either one layer of
Type I underlayment running the full length of the valley or
a self-adhering polymer-modified bitumen sheet complying
with ASTM D 1970, in addition to other required
underlayment. In areas where the average daily temperature
in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water,
the metal valley flashing underlayment shall be solidly
cemented to the roofing underlayment for slopes under
seven units vertical in 12 units horizontal (58-percent slope)
or self-adhering polymer-modified bitumen sheet shall be
installed.
1507.9.4 Interlayment. Interlayment shall comply with
ASTM D 226, Type I.
MINIMUM
GRADES
Taper sawn shakes of
naturally durable wood
LENGTH
(inches)
EXPOSURE
(inches)
4:12 PITCH
OR STEEPER
1507.10 Built-up roofs. The installation of built-up roofs shall
comply with the provisions of this section.
1507.10.1 Slope. Built-up roofs shall have a design slope of
a minimum of one-fourth unit vertical in 12 units horizontal
(2-percent slope) for drainage, except for coal-tar built-up
roofs that shall have a design slope of a minimum
one-eighth unit vertical in 12 units horizontal (1-percent
slope).
1507.10.2 Material standards. Built-up roof covering
materials shall comply with the standards in Table
1507.10.2.
1507.11 Modified bitumen roofing. The installation of modified bitumen roofing shall comply with the provisions of this
section.
273
11
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
TABLE 1507.10.2
BUILT-UP ROOFING MATERIAL STANDARDS
MATERIAL STANDARD
STANDARD
Acrylic coatings used in roofing
ASTM D 6083
Aggregate surfacing
ASTM D 1863
Asphalt adhesive used in roofing
ASTM D 3747
Asphalt cements used in roofing
ASTM D 3019; D 2822;
D 4586
Asphalt-coated glass fiber base sheet ASTM D 4601
Asphalt coatings used in roofing
ASTM D1227; D 2823; D
4479
Asphalt glass felt
ASTM D 2178
Asphalt primer used in roofing
ASTM D 41
1507.13 Thermoplastic single-ply roofing. The installation
of thermoplastic single-ply roofing shall comply with the provisions of this section.
1507.13.1 Slope. Thermoplastic single-ply membrane
roofs shall have a design slope of a minimum of one-fourth
unit vertical in 12 units horizontal (2-percent slope).
1507.13.2 Material standards. Thermoplastic single-ply
roof coverings shall comply with ASTM D 4434, ASTM D
6754, ASTM D 6878 or CGSB CAN/CGSB 37-54.
1507.14 Sprayed polyurethane foam roofing. The installation of sprayed polyurethane foam roofing shall comply with
the provisions of this section.
1507.14.1 Slope. Sprayed polyurethane foam roofs shall
have a design slope of a minimum of one-fourth unit vertical
in 12 units horizontal (2-percent slope) for drainage.
Asphalt-saturated and asphalt-coated
ASTM D 2626
organic felt base sheet
Asphalt-saturated organic felt
(perforated)
ASTM D 226
Asphalt used in roofing
ASTM D 312
Coal-tar cements used in roofing
ASTM D 4022; D 5643
Coal-tar saturated organic felt
ASTM D 227
Coal-tar pitch used in roofing
ASTM D 450; Type I or II
Coal-tar primer used in roofing,
dampproofing and waterproofing
ASTM D 43
Glass mat, coal tar
ASTM D 4990
Glass mat, venting type
ASTM D 4897
1507.14.2 Material standards. Spray-applied polyurethane foam insulation shall comply with ASTM C 1029.
1507.14.3 Application. Foamed-in-place roof insulation
shall be installed in accordance with the manufacturer’s
instructions. A liquid-applied protective coating that complies with Section 1507.15 shall be applied no less than 2
hours nor more than 72 hours following the application of
the foam.
1507.14.4 Foam plastics. Foam plastic materials and installation shall comply with Chapter 26.
1507.15 Liquid-applied coatings. The installation of liquid-applied coatings shall comply with the provisions of this
section.
1507.15.1 Slope. Liquid-applied roofs shall have a design
slope of a minimum of one-fourth unit vertical in 12 units
horizontal (2-percent slope).
Mineral-surfaced inorganic cap sheet ASTM D 3909
Thermoplastic fabrics used in
roofing
ASTM D 5665, D 5726
1507.15.2 Material standards. Liquid-applied roof coatings shall comply with ASTM C 836, ASTM C 957, ASTM
D 1227 or ASTM D 3468, ASTM D 6083 or ASTM D 6694.
1507.11.1 Slope. Modified bitumen membrane roofs shall
have a design slope of a minimum of one-fourth unit vertical
in 12 units horizontal (2-percent slope) for drainage.
1507.11.2 Material standards. Modified bitumen roof
coverings shall comply with CGSB 37-GP-56M, ASTM D
6162, ASTM D 6163, ASTM D 6164, ASTM D 6222,
ASTM D 6223 or ASTM D 6298.
1507.12 Thermoset single-ply roofing. The installation of
thermoset single-ply roofing shall comply with the provisions
of this section.
SECTION 1508
ROOF INSULATION
1508.1 General. The use of above-deck thermal insulation
shall be permitted provided such insulation is covered with an
approved roof covering and passes the tests of FM 4450 or UL
1256 when tested as an assembly.
Exceptions:
1. Foam plastic roof insulation shall conform to the
material and installation requirements of Chapter 26.
1507.12.1 Slope. Thermoset single-ply membrane roofs
shall have a design slope of a minimum of one-fourth unit
vertical in 12 units horizontal (2-percent slope) for drainage.
2. Where a concrete roof deck is used and the
above-deck thermal insulation is covered with an
approved roof covering.
1508.1.1 Cellulosic fiberboard. Cellulosic fiberboard roof
insulation shall conform to the material and installation
requirements of Chapter 23.
1507.12.2 Material standards. Thermoset single-ply roof
coverings shall comply with ASTM D 4637, ASTM D 5019
or CGSB 37-GP-52M.
2006 INTERNATIONAL BUILDING CODE®
274
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:02 AM
12
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
fire separation distance of 20 feet (6096 mm) or
greater from a common property line shall be of
Type IV or noncombustible construction. Roofs
shall be constructed of materials and fire-resistance rated as required in Table 601. Interior framing and walls shall be Type IV or noncombustible
construction.
1508.2 Material standards. Above-deck thermal insulation
board shall comply with the standards in Table 1508.2.
TABLE 1508.2
MATERIAL STANDARDS FOR ROOF INSULATION
Cellular glass board
ASTM C 552
Composite boards
ASTM C 1289, Type III, IV, V or
VI
Expanded polystyrene
ASTM C 578
3. Unprotected noncombustible enclosures housing
only mechanical equipment and located with a
minimum fire separation distance of 20 feet (6096
mm) shall be permitted.
Extruded polystyrene board ASTM C 578
Perlite board
ASTM C 728
Polyisocyanurate board
ASTM C 1289, Type I or Type II
Wood fiberboard
ASTM C 208
4. On one-story buildings, combustible unroofed
mechanical equipment screens, fences or similar
enclosures are permitted where located with a fire
separation distance of at least 20 feet (6096 mm)
from adjacent property lines and where not
exceeding 4 feet (1219 mm) in height above the
roof surface.
SECTION 1509
ROOFTOP STRUCTURES
5. Dormers shall be of the same type of construction
as the roof on which they are placed, or of the exterior walls of the building.
1509.1 General. The provisions of this section shall govern the
construction of rooftop structures.
1509.2 Penthouses. A penthouse or other projection above the
roof in structures of other than Type I construction shall not
exceed 28 feet (8534 mm) above the roof where used as an
enclosure for tanks or for elevators that run to the roof and in all
other cases shall not extend more than 18 feet (5486 mm) above
the roof. The aggregate area of penthouses and other rooftop
structures shall not exceed one-third the area of the supporting
roof. A penthouse, bulkhead or any other similar projection
above the roof shall not be used for purposes other than shelter
of mechanical equipment or shelter of vertical shaft openings
in the roof. Provisions such as louvers, louver blades or flashing shall be made to protect the mechanical equipment and the
building interior from the elements. Penthouses or bulkheads
used for purposes other than permitted by this section shall
conform to the requirements of this code for an additional
story. The restrictions of this section shall not prohibit the placing of wood flagpoles or similar structures on the roof of any
building.
1509.2.1 Type of construction. Penthouses shall be constructed with walls, floors and roof as required for the building.
Exceptions:
1. On buildings of Type I and II construction, the
exterior walls and roofs of penthouses with a fire
separation distance of more than 5 feet (1524 mm)
and less than 20 feet (6096 mm) shall be of at least
1-hour fire-resistance-rated noncombustible construction. Walls and roofs with a fire separation
distance of 20 feet (6096 mm) or greater shall be of
noncombustible construction. Interior framing
and walls shall be of noncombustible construction.
2. On buildings of Type III, IV and V construction,
the exterior walls of penthouses with a fire separation distance of more than 5 feet (1524 mm) and
less than 20 feet (6096 mm) shall be at least 1-hour
fire-resistance-rated construction. Walls with a
2006 INTERNATIONAL BUILDING CODE®
15_ibc_2006_pg275.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Thursday, January 05, 2006 1:01:28 PM
1509.3 Tanks. Tanks having a capacity of more than 500 gallons (2 m3) placed in or on a building shall be supported on
masonry, reinforced concrete, steel or Type IV construction
provided that, where such supports are located in the building
above the lowest story, the support shall be fire-resistance rated
as required for Type IA construction.
1509.3.1 Valve. Such tanks shall have in the bottom or on
the side near the bottom, a pipe or outlet, fitted with a suitable quick opening valve for discharging the contents in an
emergency through an adequate drain.
1509.3.2 Location. Such tanks shall not be placed over or
near a line of stairs or an elevator shaft, unless there is a solid
roof or floor underneath the tank.
1509.3.3 Tank cover. Unenclosed roof tanks shall have covers sloping toward the outer edges.
1509.4 Cooling towers. Cooling towers in excess of 250
square feet (23.2 m2) in base area or in excess of 15 feet (4572
mm) high where located on building roofs more than 50 feet
(15 240 mm) high shall be of noncombustible construction.
Cooling towers shall not exceed one-third of the supporting
roof area.
Exception: Drip boards and the enclosing construction of
wood not less than 1 inch (25 mm) nominal thickness, provided the wood is covered on the exterior of the tower with
noncombustible material.
1509.5 Towers, spires, domes and cupolas. Any tower, spire,
dome or cupola shall be of a type of construction not less in
fire-resistance rating than required for the building to which it
is attached, except that any such tower, spire, dome or cupola
that exceeds 85 feet (25 908 mm) in height above grade plane,
exceeds 200 square feet (18.6 m2) in horizontal area or is used
for any purpose other than a belfry or an architectural embellishment shall be constructed of and supported on Type I or II
construction.
275
13
Color profile: Generic CMYK printer profile
Composite Default screen
ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
1509.5.1 Noncombustible construction required. Any
tower, spire, dome or cupola that exceeds 60 feet (18 288) in
height above the highest point at which it comes in contact
with the roof, or that exceeds 200 square feet (18.6 m2) in
area at any horizontal section, or which is intended to be
used for any purpose other than a belfry or architectural
embellishment, shall be entirely constructed of and supported by noncombustible materials. Such structures shall
be separated from the building below by construction having a fire-resistance rating of not less than 1.5 hours with
openings protected with a minimum 1.5-hour fire-protection rating. Structures, except aerial supports 12 feet (3658
mm) high or less, flagpoles, water tanks and cooling towers,
placed above the roof of any building more than 50 feet (15
240 mm) in height, shall be of noncombustible material and
shall be supported by construction of noncombustible material.
1509.5.2 Towers and spires. Towers and spires where
enclosed shall have exterior walls as required for the building to which they are attached. The roof covering of spires
shall be of a class of roof covering as required for the main
roof of the rest of the structure.
SECTION 1510
REROOFING
2. Metal panel, metal shingle and concrete and clay tile
roof coverings shall be permitted to be installed over
existing wood shake roofs when applied in accordance with Section 1510.4.
3. The application of a new protective coating over an
existing spray polyurethane foam roofing system
shall be permitted without tear-off of existing roof
coverings.
1510.4 Roof recovering. Where the application of a new roof
covering over wood shingle or shake roofs creates a combustible concealed space, the entire existing surface shall be covered
with gypsum board, mineral fiber, glass fiber or other approved
materials securely fastened in place.
1510.5 Reinstallation of materials. Existing slate, clay or
cement tile shall be permitted for reinstallation, except that
damaged, cracked or broken slate or tile shall not be reinstalled.
Existing vent flashing, metal edgings, drain outlets, collars and
metal counterflashings shall not be reinstalled where rusted,
damaged or deteriorated. Aggregate surfacing materials shall
not be reinstalled.
1510.6 Flashings. Flashings shall be reconstructed in accordance with approved manufacturer’s installation instructions.
Metal flashing to which bituminous materials are to be adhered
shall be prim ed prior to installation.
1510.1 General. Materials and methods of application used for
recovering or replacing an existing roof covering shall comply
with the requirements of Chapter 15.
Exception: Reroofing shall not be required to meet the minimum design slope requirement of one-quarter unit vertical
in 12 units horizontal (2-percent slope) in Section 1507 for
roofs that provide positive roof drainage.
1510.2 Structural and construction loads. Structural roof
components shall be capable of supporting the roof-covering
system and the material and equipment loads that will be
encountered during installation of the system.
1510.3 Recovering versus replacement. New roof coverings
shall not be installed without first removing all existing layers
of roof coverings where any of the following conditions occur:
1. Where the existing roof or roof covering is water soaked
or has deteriorated to the point that the existing roof or
roof covering is not adequate as a base for additional
roofing.
2. Where the existing roof covering is wood shake, slate,
clay, cement or asbestos-cement tile.
3. Where the existing roof has two or more applications of
any type of roof covering.
Exceptions:
1. Complete and separate roofing systems, such as
standing-seam metal roof systems, that are designed
to transmit the roof loads directly to the building’s
structural system and that do not rely on existing roofs
and roof coverings for support, shall not require the
removal of existing roof coverings.
2006 INTERNATIONAL BUILDING CODE®
276
15_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\15_ibc_2006.vp
Wednesday, December 07, 2005 10:53:02 AM
14
Color profile: Generic CMYK printer profile
Composite Default screen
CHAPTER 16
STRUCTURAL DESIGN
ESSENTIAL FACILITIES. Buildings and other structures
that are intended to remain operational in the event of extreme
environmental loading from flood, wind, snow or earthquakes.
1602.1 Definitions. The following words and terms shall, for
the purposes of this chapter, have the meanings shown herein.
ALLOWABLE STRESS DESIGN. A method of proportioning structural members, such that elastically computed stresses
produced in the members by nominal loads do not exceed specified allowable stresses (also called “working stress design”).
FACTORED LOAD. The product of a nominal load and a load
factor.
BALCONY, EXTERIOR. An exterior floor projecting from
and supported by a structure without additional independent
supports.
GUARD. See Section 1002.1.
➡ DEAD LOADS. The weight of materials of construction
incorporated into the building, including but not limited to
walls, floors, roofs, ceilings, stairways, built-in partitions, finishes, cladding and other similarly incorporated architectural
and structural items, and the weight of fixed service equipment,
such as cranes, plumbing stacks and risers, electrical feeders,
heating, ventilating and air-conditioning systems and fire
sprinkler systems.
DECK. An exterior floor supported on at least two opposing
sides by an adjacent structure, and/or posts, piers or other independent supports.
IMPACT LOAD. The load resulting from moving machinery,
elevators, craneways, vehicles and other similar forces and
kinetic loads, pressure and possible surcharge from fixed or
moving loads.
LIMIT STATE. A condition beyond which a structure or
member becomes unfit for service and is judged to be no longer
useful for its intended function (serviceability limit state) or to
be unsafe (strength limit state).
LIVE LOADS. Those loads produced by the use and occupancy of the building or other structure and do not include construction or environmental loads such as wind load, snow load,
rain load, earthquake load, flood load or dead load.
➡ DESIGN STRENGTH. The product of the nominal strength
and a resistance factor (or strength reduction factor).
DIAPHRAGM. A horizontal or sloped system acting to transmit lateral forces to the vertical-resisting elements. When the
term “diaphragm” is used, it shall include horizontal bracing
systems.
Diaphragm, blocked. In light-frame construction, a diaphragm in which all sheathing edges not occurring on a
framing member are supported on and fastened to blocking.
Diaphragm boundary. In light-frame construction, a location where shear is transferred into or out of the diaphragm
sheathing. Transfer is either to a boundary element or to
another force-resisting element.
LIVE LOADS (ROOF). Those loads produced (1) during
maintenance by workers, equipment and materials; and (2)
during the life of the structure by movable objects such as
planters and by people.
LOAD AND RESISTANCE FACTOR DESIGN (LRFD). A
method of proportioning structural members and their connections using load and resistance factors such that no applicable
limit state is reached when the structure is subjected to appropriate load combinations. The term “LRFD” is used in the
design of steel and wood structures.
LOAD EFFECTS. Forces and deformations produced in
structural members by the applied loads.
Diaphragm chord. A diaphragm boundary element perpendicular to the applied load that is assumed to take axial
stresses due to the diaphragm moment.
Diaphragm flexible. A diaphragm is flexible for the purpose of distribution of story shear and torsional moment
where so indicated in Section 12.3.1 of ASCE 7, as modified
in Section 1613.6.1.
LOAD FACTOR. A factor that accounts for deviations of the
actual load from the nominal load, for uncertainties in the analysis that transforms the load into a load effect, and for the probability that more than one extreme load will occur
simultaneously.
LOADS. Forces or other actions that result from the weight of
building materials, occupants and their possessions, environ-
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:44 AM
FABRIC PARTITIONS. A partition consisting of a finished
surface made of fabric, without a continuous rigid backing, that
is directly attached to a framing system in which the vertical
framing members are spaced greater than 4 feet (1219 mm) on
center.
277
1
➡
SECTION 1602
DEFINITIONS AND NOTATIONS
DURATION OF LOAD. The period of continuous application of a given load, or the aggregate of periods of intermittent
applications of the same load.
➡
1601.1 Scope. The provisions of this chapter shall govern the
structural design of buildings, structures and portions thereof
regulated by this code.
Diaphragm, rigid. A diaphragm is rigid for the purpose of
distribution of story shear and torsional moment when the
lateral deformation of the diaphragm is less than or equal to
two times the average story drift.
➡
SECTION 1601
GENERAL
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
NOMINAL LOADS. The magnitudes of the loads specified in
this chapter (dead, live, soil, wind, snow, rain, flood and earthquake).
L =
Live load, except roof live load, including any permitted live load reduction.
Lr =
Roof live load including any permitted live load
reduction.
R =
S =
Rain load.
Snow load.
T =
Self-straining force arising from contraction or
expansion resulting from temperature change,
shrinkage, moisture change, creep in component
materials, movement due to differential settlement
or combinations thereof.
W =
Load due to wind pressure.
OCCUPANCY CATEGORY. A category used to determine
structural requirements based on occupancy.
OTHER STRUCTURES. Structures, other than buildings,
for which loads are specified in this chapter.
➡ PANEL (PART OF A STRUCTURE). The section of a floor,
wall or roof comprised between the supporting frame of two
adjacent rows of columns and girders or column bands of floor
or roof construction.
RESISTANCE FACTOR. A factor that accounts for deviations of the actual strength from the nominal strength and the
manner and consequences of failure (also called “strength
reduction factor”).
➡ STRENGTH, NOMINAL. The capacity of a structure or
member to resist the effects of loads, as determined by computations using specified material strengths and dimensions and
equations derived from accepted principles of structural
mechanics or by field tests or laboratory tests of scaled models,
allowing for modeling effects and differences between laboratory and field conditions.
SECTION 1603
CONSTRUCTION DOCUMENTS
1603.1 General. Construction documents shall show the size,
section and relative locations of structural members with floor
levels, column centers and offsets dimensioned. The design
loads and other information pertinent to the structural design
required by Sections 1603.1.1 through 1603.1.8 shall be indicated on the construction documents.
Exception: Construction documents for buildings constructed in accordance with the conventional light-frame
construction provisions of Section 2308 shall indicate the
following structural design information:
1. Floor and roof live loads.
STRENGTH, REQUIRED. Strength of a member, cross section or connection required to resist factored loads or related
internal moments and forces in such combinations as stipulated
by these provisions.
2. Ground snow load, Pg.
3. Basic wind speed (3-second gust), miles per hour
(mph) (km/hr) and wind exposure.
4. Seismic design category and site class.
STRENGTH DESIGN. A method of proportioning structural
members such that the computed forces produced in the members by factored loads do not exceed the member design
strength [also called “load and resistance factor design”
(LRFD)]. The term “strength design” is used in the design of
concrete and masonry structural elements.
5. Flood design data, if located in flood hazard areas
established in Section 1612.3.
1603.1.1 Floor live load. The uniformly distributed, concentrated and impact floor live load used in the design shall
be indicated for floor areas. Use of live load reduction in
accordance with Section 1607.9 shall be indicated for each
type of live load used in the design.
VEHICLE BARRIER SYSTEM. A system of building components near open sides of a garage floor or ramp or building
walls that act as restraints for vehicles.
➡ NOTATIONS.
1603.1.2 Roof live load. The roof live load used in the
design shall be indicated for roof areas (Section 1607.11).
D =
E =
Dead load.
Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4.2 of
ASCE 7.
Em =
Maximum seismic load effect of horizontal and vertical seismic forces as set forth in Section 12.4.3 of
ASCE 7.
Load due to fluids with well-defined pressures and
maximum heights.
1603.1.3 Roof snow load. The ground snow load, Pg, shall
be indicated. In areas where the ground snow load, Pg,
exceeds 10 pounds per square foot (psf) (0.479 kN/m2), the
following additional information shall also be provided,
regardless of whether snow loads govern the design of the
roof:
F =
Fa =
H =
1. Flat-roof snow load, Pf.
2. Snow exposure factor, Ce.
3. Snow load importance factor, I.
4. Thermal factor, Ct.
Flood load.
Load due to lateral earth pressures, ground water
pressure or pressure of bulk materials.
1603.1.4 Wind design data. The following information
related to wind loads shall be shown, regardless of whether
2006 INTERNATIONAL BUILDING CODE®
278
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:44 AM
2
➡
mental effects, differential movement and restrained dimensional changes. Permanent loads are those loads in which
variations over time are rare or of small magnitude, such as
dead loads. All other loads are variable loads (see also “Nominal loads”).
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
wind loads govern the design of the lateral-force-resisting
system of the building:
1603.1.8 Systems and components requiring special
inspections for seismic resistance. Construction documents or specifications shall be prepared for those systems
and components requiring special inspection for seismic
resistance as specified in Section 1707.1 by the registered
design professional responsible for their design and shall be
submitted for approval in accordance with Section 106.1.
Reference to seismic standards in lieu of detailed drawings
is acceptable.
1. Basic wind speed (3-second gust), miles per hour
(km/hr).
2. Wind importance factor, I, and occupancy category.
3. Wind exposure, if more than one wind exposure is utilized, the wind exposure and applicable wind direction shall be indicated.
1603.2 Restrictions on loading. It shall be unlawful to place,
or cause or permit to be placed, on any floor or roof of a building, structure or portion thereof, a load greater than is permitted
by these requirements.
4. The applicable internal pressure coefficient.
5. Components and cladding. The design wind pressures in terms of psf (kN/m2) to be used for the design
of exterior component and cladding materials not specifically designed by the registered design professional.
1603.3 Live loads posted. Where the live loads for which each
floor or portion thereof of a commercial or industrial building
is or has been designed to exceed 50 psf (2.40 kN/m2), such
design live loads shall be conspicuously posted by the owner in
that part of each story in which they apply, using durable signs.
It shall be unlawful to remove or deface such notices.
1603.1.5 Earthquake design data. The following information related to seismic loads shall be shown, regardless of
whether seismic loads govern the design of the lateral-force-resisting system of the building:
1603.4 Occupancy permits for changed loads. Occupancy
permits for buildings hereafter erected shall not be issued until
the floor load signs, required by Section 1603.3, have been
installed.
1. Seismic importance factor, I, and occupancy
category.
2. Mapped spectral response accelerations, SS and S1.
3. Site class.
4. Spectral response coefficients, SDS and SD1.
SECTION 1604
GENERAL DESIGN REQUIREMENTS
5. Seismic design category.
6. Basic seismic-force-resisting system(s).
1604.1 General. Building, structures and parts thereof shall be
designed and constructed in accordance with strength design,
load and resistance factor design, allowable stress design,
empirical design or conventional construction methods, as permitted by the applicable material chapters.
7. Design base shear.
8. Seismic response coefficient(s), CS.
9. Response modification factor(s), R.
10. Analysis procedure used.
1603.1.6 Flood design data. For buildings located in whole
or in part in flood hazard areas as established in Section
1612.3, the documentation pertaining to design, if required
in Section 1612.5, shall be included and the following information, referenced to the datum on the community’s Flood
Insurance Rate Map (FIRM), shall be shown, regardless of
whether flood loads govern the design of the building:
1604.2 Strength. Buildings and other structures, and parts
thereof, shall be designed and constructed to support safely the
factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other
structures, and parts thereof, shall be designed and constructed
to support safely the nominal loads in load combinations
defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.
1. In flood hazard areas not subject to high-velocity
wave action, the elevation of the proposed lowest
floor, including the basement.
Loads and forces for occupancies or uses not covered in this
chapter shall be subject to the approval of the building official.
2. In flood hazard areas not subject to high-velocity
wave action, the elevation to which any nonresidential building will be dry floodproofed.
1604.3 Serviceability. Structural systems and members
thereof shall be designed to have adequate stiffness to limit
deflections and lateral drift. See Section 12.12.1 of ASCE 7 for
drift limits applicable to earthquake loading.
3. In flood hazard areas subject to high-velocity wave
action, the proposed elevation of the bottom of the
lowest horizontal structural member of the lowest
floor, including the basement.
1603.1.7 Special loads. Special loads that are applicable to
the design of the building, structure or portions thereof shall
be indicated along with the specified section of this code
that addresses the special loading condition.
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:44 AM
1604.3.1 Deflections. The deflections of structural members shall not exceed the more restrictive of the limitations
of Sections 1604.3.2 through 1604.3.5 or that permitted by
Table 1604.3.
1604.3.2 Reinforced concrete. The deflection of reinforced concrete structural members shall not exceed that
permitted by ACI 318.
279
3
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
TABLE 1604.3
DEFLECTION LIMITSa, b, c, h, i
L
S or W f
D + Ld,g
Roof members:e
Supporting plaster ceiling
Supporting nonplaster ceiling
Not supporting ceiling
l/360
l/240
l/180
l/360
l/240
l/180
l/240
l/180
l/120
Floor members
l/360
—
l/240
—
—
l/240
l/120
—
—
Farm buildings
—
—
l/180
Greenhouses
—
—
l/120
CONSTRUCTION
Exterior walls and interior
partitions:
With brittle finishes
With flexible finishes
For SI: 1 foot = 304.8 mm.
a. For structural roofing and siding made of formed metal sheets, the total load
deflection shall not exceed l/60. For secondary roof structural members supporting formed metal roofing, the live load deflection shall not exceed l/150.
For secondary wall members supporting formed metal siding, the design
wind load deflection shall not exceed l/90. For roofs, this exception only
applies when the metal sheets have no roof covering.
b. Interior partitions not exceeding 6 feet in height and flexible, folding and
portable partitions are not governed by the provisions of this section. The
deflection criterion for interior partitions is based on the horizontal load
defined in Section 1607.13.
c. See Section 2403 for glass supports.
d. For wood structural members having a moisture content of less than 16 percent at time of installation and used under dry conditions, the deflection
resulting from L + 0.5D is permitted to be substituted for the deflection
resulting from L + D.
e. The above deflections do not ensure against ponding. Roofs that do not have
sufficient slope or camber to assure adequate drainage shall be investigated
for ponding. See Section 1611 for rain and ponding requirements and Section 1503.4 for roof drainage requirements.
f. The wind load is permitted to be taken as 0.7 times the “component and cladding” loads for the purpose of determining deflection limits herein.
g. For steel structural members, the dead load shall be taken as zero.
h. For aluminum structural members or aluminum panels used in skylights and
sloped glazing framing, roofs or walls of sunroom additions or patio covers,
not supporting edge of glass or aluminum sandwich panels, the total load
deflection shall not exceed l/60. For aluminum sandwich panels used in roofs
or walls of sunroom additions or patio covers, the total load deflection shall
not exceed l/120.
i. For cantilever members, l shall be taken as twice the length of the cantilever.
1604.3.3 Steel. The deflection of steel structural members
shall not exceed that permitted by AISC 360, AISI-NAS,
AISI-General, AISI-Truss, ASCE 3, ASCE 8, SJI JG-1.1,
SJI K-1.1 or SJI LH/DLH-1.1, as applicable.
1604.3.4 Masonry. The deflection of masonry structural
members shall not exceed that permitted by ACI 530/ASCE
5/TMS 402.
1604.3.5 Aluminum. The deflection of aluminum structural members shall not exceed that permitted by AA
ADM1.
1604.3.6 Limits. Deflection of structural members over
span, l, shall not exceed that permitted by Table 1604.3.
1604.4 Analysis. Load effects on structural members and their
connections shall be determined by methods of structural analysis that take into account equilibrium, general stability, geometric compatibility and both short- and long-term material
properties.
Members that tend to accumulate residual deformations
under repeated service loads shall have included in their analysis the added eccentricities expected to occur during their service life.
Any system or method of construction to be used shall be
based on a rational analysis in accordance with well-established
principles of mechanics. Such analysis shall result in a system
that provides a complete load path capable of transferring loads
from their point of origin to the load-resisting elements.
The total lateral force shall be distributed to the various vertical elements of the lateral-force-resisting system in proportion
to their rigidities, considering the rigidity of the horizontal
bracing system or diaphragm. Rigid elements assumed not to
be a part of the lateral-force-resisting system are permitted to
be incorporated into buildings provided their effect on the
action of the system is considered and provided for in the
design. Except where diaphragms are flexible, or are permitted
to be analyzed as flexible, provisions shall be made for the
increased forces induced on resisting elements of the structural
system resulting from torsion due to eccentricity between the
center of application of the lateral forces and the center of rigidity of the lateral-force-resisting system.
Every structure shall be designed to resist the overturning
effects caused by the lateral forces specified in this chapter. See
Section 1609 for wind loads, Section 1610 for lateral soil loads
and Section 1613 for earthquake loads.
1604.5 Occupancy category. Buildings shall be assigned an
occupancy category in accordance with Table 1604.5.
1604.5.1 Multiple occupancies. Where a structure is occupied by two or more occupancies not included in the same
occupancy category, the structure shall be assigned the classification of the highest occupancy category corresponding
to the various occupancies. Where structures have two or
more portions that are structurally separated, each portion
shall be separately classified. Where a separated portion of a
structure provides required access to, required egress from
or shares life safety components with another portion having a higher occupancy category, both portions shall be
assigned to the higher occupancy category.
1604.6 In-situ load tests. The building official is authorized to
require an engineering analysis or a load test, or both, of any
construction whenever there is reason to question the safety of
the construction for the intended occupancy. Engineering analysis and load tests shall be conducted in accordance with Section 1713.
1604.7 Preconstruction load tests. Materials and methods of
construction that are not capable of being designed by
approved engineering analysis or that do not comply with the
applicable material design standards listed in Chapter 35, or
alternative test procedures in accordance with Section 1711,
shall be load tested in accordance with Section 1714.
2006 INTERNATIONAL BUILDING CODE®
280
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:45 AM
4
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
TABLE 1604.5
OCCUPANCY CATEGORY OF BUILDINGS AND OTHER STRUCTURES
OCCUPANCY
CATEGORY
NATURE OF OCCUPANCY
I
Buildings and other structures that represent a low hazard to human life in the event of failure, including but not limited
to:
Ÿ Agricultural facilities.
Ÿ Certain temporary facilities.
Ÿ Minor storage facilities.
II
Buildings and other structures except those listed in Occupancy Categories I, III and IV
III
Buildings and other structures that represent a substantial hazard to human life in the event of failure, including but not
limited to:
Ÿ Covered structures whose primary occupancy is public assembly with an occupant load greater than 300.
Ÿ Buildings and other structures with elementary school, secondary school or day care facilities with an occupant load
greater than 250.
Ÿ Buildings and other structures with an occupant load greater than 500 for colleges or adult education facilities.
Ÿ Health care facilities with an occupant load of 50 or more resident patients, but not having surgery or emergency treatment
facilities.
Ÿ Jails and detention facilities.
Ÿ Any other occupancy with an occupant load greater than 5,000.
Ÿ Power-generating stations, water treatment for potable water, waste water treatment facilities and other public utility facilities not included in Occupancy Category IV.
Ÿ Buildings and other structures not included in Occupancy Category IV containing sufficient quantities of toxic or explosive substances to be dangerous to the public if released.
Buildings and other structures designated as essential facilities, including but not limited to:
Hospitals and other health care facilities having surgery or emergency treatment facilities.
Fire, rescue and police stations and emergency vehicle garages.
Designated earthquake, hurricane or other emergency shelters.
Designated emergency preparedness, communication, and operation centers and other facilities required for emergency
response.
Ÿ Power-generating stations and other public utility facilities required as emergency backup facilities for Occupancy Category IV structures.
Ÿ Structures containing highly toxic materials as defined by Section 307 where the quantity of the material exceeds the maximum allowable quantities of Table 307.1.(2).
Ÿ Aviation control towers, air traffic control centers and emergency aircraft hangars.
Ÿ Buildings and other structures having critical national defense functions.
Ÿ Water treatment facilities required to maintain water pressure for fire suppression.
Ÿ
Ÿ
Ÿ
Ÿ
IV
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:45 AM
281
5
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
1605.2.1 Basic load combinations. Where strength design
or load and resistance factor design is used, structures and
portions thereof shall resist the most critical effects from the
following combinations of factored loads:
1604.8 Anchorage.
1604.8.1 General. Anchorage of the roof to walls and columns, and of walls and columns to foundations, shall be
provided to resist the uplift and sliding forces that result
from the application of the prescribed loads.
1604.8.2 Concrete and masonry walls. Concrete and
masonry walls shall be anchored to floors, roofs and other
structural elements that provide lateral support for the wall.
Such anchorage shall provide a positive direct connection
capable of resisting the horizontal forces specified in this
chapter but not less than a minimum strength design horizontal force of 280 plf (4.10 kN/m) of wall, substituted for
“E” in the load combinations of Section 1605.2 or 1605.3.
Walls shall be designed to resist bending between anchors
where the anchor spacing exceeds 4 feet (1219 mm).
Required anchors in masonry walls of hollow units or cavity
walls shall be embedded in a reinforced grouted structural
element of the wall. See Sections 1609 for wind design
requirements and see Section 1613 for earthquake design
requirements.
1604.8.3 Decks. Where supported by attachment to an exterior
wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of
toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during
inspection, decks shall be self-supporting. For decks with cantilevered framing members, connections to exterior walls or
other framing members shall be designed and constructed to
resist uplift resulting from the full live load specified in Table
1607.1 acting on the cantilevered portion of the deck.
(Equation 16-1)
1.2(D + F + T) + 1.6(L + H) +
0.5 (Lr or S or R)
(Equation 16-2)
1.2D + 1.6(Lr or S or R) + (f1L or 0.8W)
(Equation 16-3)
1.2D + 1.6W + f1L + 0.5(Lr or S or R)
(Equation 16-4)
1.2D + 1.0E + f1L + f2S
(Equation 16-5)
0.9D + 1.6W + 1.6H
(Equation 16-6)
0.9D + 1.0E + 1.6H
(Equation 16-7)
f1 = 1 for floors in places of public assembly, for live loads
in excess of 100 pounds per square foot (4.79 kN/m2),
and for parking garage live load, and
= 0.5 for other live loads.
f2 = 0.7 for roof configurations (such as saw tooth) that do
not shed snow off the structure, and
= 0.2 for other roof configurations.
Exception: Where other factored load combinations are
specifically required by the provisions of this code, such
combinations shall take precedence.
1605.2.2 Other loads. Where Fa is to be considered in the
design, the load combinations of Section 2.3.3 of ASCE 7
shall be used.
1605.3 Load combinations using allowable stress design.
1604.9 Counteracting structural actions. Structural members, systems, components and cladding shall be designed to
resist forces due to earthquake and wind, with consideration of
overturning, sliding, and uplift. Continuous load paths shall be
provided for transmitting these forces to the foundation. Where
sliding is used to isolate the elements, the effects of friction
between sliding elements shall be included as a force.
1605.3.1 Basic load combinations. Where allowable stress
design (working stress design), as permitted by this code, is
used, structures and portions thereof shall resist the most
critical effects resulting from the following combinations of
loads:
1604.10 Wind and seismic detailing. Lateral-force-resisting
systems shall meet seismic detailing requirements and limitations prescribed in this code and ASCE 7, excluding Chapter
14 and Appendix 11A, even when wind code prescribed load
effects are greater than seismic load effects.
SECTION 1605
LOAD COMBINATIONS
1605.1 General. Buildings and other structures and portions
thereof shall be designed to resist the load combinations specified in Section 1605.2 or 1605.3 and Chapters 18 through 23,
and the special seismic load combinations of Section 1605.4
where required by Section 12.3.3.3 or 12.10.2.1 of ASCE 7.
Applicable loads shall be considered, including both earthquake and wind, in accordance with the specified load combinations. Each load combination shall also be investigated with
one or more of the variable loads set to zero.
D+F
(Equation 16-8)
D+H+F+L+T
(Equation 16-9)
D + H + F + (Lr or S or R)
(Equation 16-10)
D + H + F + 0.75(L + T) +
0.75 (Lr or S or R)
(Equation 16-11)
D + H + F + (W or 0.7E)
(Equation 16-12)
D + H + F + 0.75(W or 0.7E) +
0.75L + 0.75 (Lr or S or R)
(Equation 16-13)
0.6D + W + H
(Equation 16-14)
0.6D + 0.7E + H
(Equation 16-15)
Exceptions:
1. Crane hook loads need not be combined with roof
live load or with more than three-fourths of the
snow load or one-half of the wind load.
2. Flat roof snow loads of 30 psf (1.44 kN/m2) or less
need not be combined with seismic loads. Where
1605.2 Load combinations using strength design or load
and resistance factor design.
2006 INTERNATIONAL BUILDING CODE®
282
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:45 AM
1.4 (D + F)
6
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
flat roof snow loads exceed 30 psf (1.44 kN/m2),
20 percent shall be combined with seismic loads.
elements and components shall be designed to resist the forces
calculated using Equation 16-22 when the effects of the seismic ground motion are additive to gravity forces and those calculated using Equation 16-23 when the effects of the seismic
ground motion counteract gravity forces.
1605.3.1.1 Stress increases. Increases in allowable
stresses specified in the appropriate material chapter or
the referenced standards shall not be used with the load
combinations of Section 1605.3.1, except that a duration
of load increase shall be permitted in accordance with
Chapter 23.
1605.3.1.2 Other loads. Where Fa is to be considered in
design, the load combinations of Section 2.4.2 of ASCE
7 shall be used.
(Equation 16-16)
D + L + (ωW)
(Equation 16-17)
D + L + ωW + S/2
(Equation 16-18)
D + L + S + ωW/2
(Equation 16-19)
D + L + S + E/1.4
(Equation 16-20)
0.9D + E/1.4
(Equation 16-21)
0.9D + Em
(Equation 16-23)
Em = The maximum effect of horizontal and vertical forces
as set forth in Section 12.4.3 of ASCE 7.
f1 = 1 for floors in places of public assembly, for live loads
in excess of 100 psf (4.79 kN/m2) and for parking
garage live load, or
= 0.5 for other live loads.
1605.5 Heliports and helistops. Heliport and helistop landing
areas shall be designed for the following loads, combined in
accordance with Section 1605:
1. Dead load, D, plus the gross weight of the helicopter, Dh,
plus snow load, S.
2. Dead load, D, plus two single concentrated impact loads,
L, approximately 8 feet (2438 mm) apart applied anywhere on the landing area (representing the helicopter’s
two main landing gear, whether skid type or wheeled
type), having a magnitude of 0.75 times the gross weight
of the helicopter. Both loads acting together total
one-and one half times the gross weight of the helicopter.
3. Dead load, D, plus a uniform live load, L, of 100 psf (4.79
kN/m2).
Exception: Landing areas designed for helicopters
with gross weights not exceeding 3,000 pounds
(13.34 kN) in accordance with Items 1 and 2 shall be
permitted to be designed using a 40 psf (1.92 kN/m2)
uniform live load in Item 3, provided the landing area
is identified with a 3,000 pound (13.34 kN) weight
limitation. This 40 psf (1.92 kN/m2) uniform live load
shall not be reduced. The landing area weight limitation shall be indicated by the numeral “3” (kips)
located in the bottom right corner of the landing area
as viewed from the primary approach path. The landing area weight limitation shall be a minimum of 5
feet (1524 mm) in height.
Exceptions:
1. Crane hook loads need not be combined with roof live
loads or with more than three-fourths of the snow load
or one-half of the wind load.
2. Flat roof snow loads of 30 psf (1.44 kN/m2) or less
need not be combined with seismic loads. Where flat
roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.
SECTION 1606
DEAD LOADS
1606.1 General. Dead loads are those loads defined in Section
1602.1. Dead loads shall be considered permanent loads.
1605.3.2.1 Other loads. Where F, H or T are to be considered in the design, each applicable load shall be added
to the combinations specified in Section 1605.3.2.
1606.2 Design dead load. For purposes of design, the actual
weights of materials of construction and fixed service equipment shall be used. In the absence of definite information, values used shall be subject to the approval of the building official.
1605.4 Special seismic load combinations. For both allowable stress design and strength design methods where specifically required by Section 1605.1 or by Chapters 18 through 23,
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:45 AM
(Equation 16-22)
where:
1605.3.2 Alternative basic load combinations. In lieu of the
basic load combinations specified in Section 1605.3.1, structures and portions thereof shall be permitted to be designed for
the most critical effects resulting from the following combinations. When using these alternative basic load combinations
that include wind or seismic loads, allowable stresses are permitted to be increased or load combinations reduced where
permitted by the material chapter of this code or the referenced
standards. For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely to be in place during a design wind event
shall be used. Where wind loads are calculated in accordance
with Chapter 6 of ASCE 7, the coefficient ω in the following
equations shall be taken as 1.3. For other wind loads, ω shall be
taken as 1. When using these alternative load combinations to
evaluate sliding, overturning and soil bearing at the soil-structure interface, the reduction of foundation overturning from
Section 12.13.4 in ASCE 7 shall not be used. When using these
alternative basic load combinations for proportioning foundations for loadings, which include seismic loads, the vertical
seismic load effect, Ev, in Equation 12.4-4 of ASCE 7 is permitted to be taken equal to zero.
D + L + (Lr or S or R)
1.2D + f1L + Em
283
7
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
SECTION 1607
LIVE LOADS
vidual lanes so as to produce the maximum stress in each
structural member. Single spans shall be designed for the
uniform load in Table 1607.6 and one simultaneous concentrated load positioned to produce the maximum effect. Multiple spans shall be designed for the uniform load in Table
1607.6 on the spans and two simultaneous concentrated
loads in two spans positioned to produce the maximum negative moment effect. Multiple span design loads, for other
effects, shall be the same as for single spans.
1607.1 General. Live loads are those loads defined in Section
1602.1.
1607.2 Loads not specified. For occupancies or uses not designated in Table 1607.1, the live load shall be determined in
accordance with a method approved by the building official.
1607.3 Uniform live loads. The live loads used in the design of
buildings and other structures shall be the maximum loads
expected by the intended use or occupancy but shall in no case
be less than the minimum uniformly distributed unit loads
required by Table 1607.1.
1607.7 Loads on handrails, guards, grab bars and vehicle
barriers. Handrails, guards, grab bars as designed in ICC
A117.1 and vehicle barriers shall be designed and constructed
to the structural loading conditions set forth in this section.
1607.4 Concentrated loads. Floors and other similar surfaces
shall be designed to support the uniformly distributed live
loads prescribed in Section 1607.3 or the concentrated load, in
pounds (kilonewtons), given in Table 1607.1, whichever produces the greater load effects. Unless otherwise specified, the
indicated concentration shall be assumed to be uniformly distributed over an area 2.5 feet by 2.5 feet [6.25 square feet (0.58
m2)] and shall be located so as to produce the maximum load
effects in the structural members.
1607.7.1 Handrails and guards. Handrail assemblies and
guards shall be designed to resist a load of 50 plf (0.73
kN/m) applied in any direction at the top and to transfer this
load through the supports to the structure. Glass handrail
assemblies and guards shall also comply with Section 2407.
Exceptions:
1. For one- and two-family dwellings, only the single
concentrated load required by Section 1607.7.1.1
shall be applied.
1607.5 Partition loads. In office buildings and in other buildings where partition locations are subject to change, provisions
for partition weight shall be made, whether or not partitions are
shown on the construction documents, unless the specified live
load exceeds 80 psf (3.83 kN/m2). The partition load shall not
be less than a uniformly distributed live load of 15 psf (0.74
kN/m2).
2. In Group I-3, F, H and S occupancies, for areas that
are not accessible to the general public and that
have an occupant load less than 50, the minimum
load shall be 20 pounds per foot (0.29 kN/m).
1607.7.1.1 Concentrated load. Handrail assemblies
and guards shall be able to resist a single concentrated
load of 200 pounds (0.89 kN), applied in any direction at
any point along the top, and have attachment devices and
supporting structure to transfer this loading to appropriate structural elements of the building. This load need not
be assumed to act concurrently with the loads specified
in the preceding paragraph.
1607.6 Truck and bus garages. Minimum live loads for
garages having trucks or buses shall be as specified in Table
1607.6, but shall not be less than 50 psf (2.40 kN/m2), unless
other loads are specifically justified and approved by the building official. Actual loads shall be used where they are greater
than the loads specified in the table.
TABLE 1607.6
UNIFORM AND CONCENTRATED LOADS
UNIFORM LOAD
(pounds/linear
foot of lane)
For moment
design
For shear
design
H20-44 and
HS20-44
640
18,000
26,000
H15-44 and
HS15-44
480
13,500
19,500
LOADING
CLASSa
1607.7.1.2 Components. Intermediate rails (all those
except the handrail), balusters and panel fillers shall be
designed to withstand a horizontally applied normal load
of 50 pounds (0.22 kN) on an area equal to 1 square foot
(0.093m2), including openings and space between rails.
Reactions due to this loading are not required to be
superimposed with those of Section 1607.7.1 or
1607.7.1.1.
CONCENTRATED LOAD
(pounds)b
For SI: 1 pound per linear foot = 0.01459 kN/m, 1 pound = 0.004448 kN,
1 ton = 8.90 kN.
a. An H loading class designates a two-axle truck with a semitrailer. An HS
loading class designates a tractor truck with a semitrailer. The numbers following the letter classification indicate the gross weight in tons of the standard truck and the year the loadings were instituted.
b. See Section 1607.6.1 for the loading of multiple spans.
1607.7.1.3 Stress increase. Where handrails and guards
are designed in accordance with the provisions for allowable stress design (working stress design) exclusively for
the loads specified in Section 1607.7.1, the allowable
stress for the members and their attachments are permitted to be increased by one-third.
1607.6.1 Truck and bus garage live load application. The
concentrated load and uniform load shall be uniformly distributed over a 10-foot (3048 mm) width on a line normal to
the centerline of the lane placed within a 12-foot-wide
(3658 mm) lane. The loads shall be placed within their indi-
1607.7.2 Grab bars, shower seats and dressing room
bench seats. Grab bars, shower seats and dressing room
bench seat systems shall be designed to resist a single concentrated load of 250 pounds (1.11 kN) applied in any direction at any point.
2006 INTERNATIONAL BUILDING CODE®
284
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:46 AM
8
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
TABLE 1607.1
MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS AND MINIMUM CONCENTRATED LIVE LOADSg
OCCUPANCY OR USE
UNIFORM
(psf)
CONCENTRATED
(lbs.)
23. Libraries
Corridors above first floor
Reading rooms
Stack rooms
80
60
150b
1,000
1,000
1,000
24. Manufacturing
Heavy
Light
250
125
3,000
2,000
25. Marquees
75
—
80
2,000
UNIFORM CONCENTRATED
(psf)
(lbs.)
1. Apartments (see residential)
—
—
2. Access floor systems
Office use
Computer use
50
100
2,000
2,000
3. Armories and drill rooms
150
—
4. Assembly areas and theaters
Fixed seats (fastened to floor)
Follow spot, projections and control
rooms
Lobbies
Movable seats
Stages and platforms
OCCUPANCY OR USE
60
50
100
100
125
—
5. Balconies
On one- and two-family residences only,
and not exceeding 100 sq ft
100
60
6. Bowling alleys
75
—
7. Catwalks
40
300
8. Dance halls and ballrooms
100
—
—
occupancy
servedh
—
10. Dining rooms and restaurants
100
—
11. Dwellings (see residential)
—
—
12. Cornices
60
—
13. Corridors, except as otherwise indicated
100
—
14. Elevator machine room grating
2
(on area of 4 in )
—
300
15. Finish light floor plate construction
2
(on area of 1 in )
—
—
200
16. Fire escapes
On single-family dwellings only
100
40
—
17. Garages (passenger vehicles only)
Trucks and buses
40
Note a
See Section 1607.6
18. Grandstands (see stadium and arena
bleachers)
—
—
19. Gymnasiums, main floors and
balconies
100
—
20. Handrails, guards and grab bars
See Section 1607.7
21. Hospitals
Corridors above first floor
Operating rooms, laboratories
Patient rooms
80
60
40
1,000
1,000
1,000
22. Hotels (see residential)
—
—
—
—
100
50
2,000
2,000
27. Penal institutions
Cell blocks
Corridors
40
100
—
28. Residential
One- and two-family dwellings
i
Uninhabitable attics without storage
Uninhabitable attics with limited
i, j, k
storage
Habitable attics and sleeping areas
All other areas except balconies and
decks
Hotels and multiple-family dwellings
Private rooms and corridors
serving them
Public rooms and corridors
serving them
Same as
9. Decks
26. Office buildings
Corridors above first floor
File and computer rooms shall be
designed for heavier loads based
on anticipated occupancy
Lobbies and first-floor corridors
Offices
29. Reviewing stands, grandstands and
bleachers
10
20
30
40
—
40
100
Note c
30. Roofs
All roof surfaces subject to maintenance
workers
Awnings and canopies
Fabric construction supported by a
5
lightweight rigid skeleton structure nonreduceable
All other construction
20
Ordinary flat, pitched, and curved roofs
20
Primary roof members, exposed to a
work floor
Single panel point of lower chord of
roof trusses or any point along
primary structural members
supporting roofs:
Over manufacturing, storage
warehouses, and repair garages
All other occupancies
Roofs used for other special purposes
Note 1
Roofs used for promenade purposes
60
Roofs used for roof gardens or
100
assembly purposes
300
2,000
300
Note 1
(continued)
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006_pg285.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Thursday, January 05, 2006 1:04:31 PM
285
9
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
TABLE 1607.1—continued
MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS AND
MINIMUM CONCENTRATED LIVE LOADSg
OCCUPANCY OR USE
31. Schools
Classrooms
Corridors above first floor
First-floor corridors
UNIFORM CONCENTRATED
(psf)
(lbs.)
40
80
100
1,000
1,000
1,000
32. Scuttles, skylight ribs and accessible
ceilings
—
200
33. Sidewalks, vehicular driveways and
yards, subject to trucking
250d
8,000e
34. Skating rinks
100
—
35. Stadiums and arenas
Bleachers
Fixed seats (fastened to floor)
100c
60c
—
36. Stairs and exits
One- and two-family dwellings
All other
40
100
Note f
37. Storage warehouses (shall be designed
for heavier loads if required for anticipated storage)
Heavy
Light
250
125
38. Stores
Retail
First floor
Upper floors
Wholesale, all floors
100
75
125
39. Vehicle barriers
See Section 1607.7.3
40. Walkways and elevated platforms (other
than exitways)
60
41. Yards and terraces, pedestrians
100
g. Where snow loads occur that are in excess of the design conditions, the
structure shall be designed to support the loads due to the increased loads
caused by drift buildup or a greater snow design determined by the building
official (see Section 1608). For special-purpose roofs, see Section
1607.11.2.2.
h. See Section 1604.8.3 for decks attached to exterior walls.
i. Attics without storage are those where the maximum clear height between
the joist and rafter is less than 42 inches, or where there are not two or more
adjacent trusses with the same web configuration capable of containing a
rectangle 42 inches high by 2 feet wide, or greater, located within the plane
of the truss. For attics without storage, this live load need not be assumed to
act concurrently with any other live load requirements.
j. For attics with limited storage and constructed with trusses, this live load
need only be applied to those portions of the bottom chord where there are
two or more adjacent trusses with the same web configuration capable of
containing a rectangle 42 inches high by 2 feet wide or greater, located
within the plane of the truss. The rectangle shall fit between the top of the
bottom chord and the bottom of any other truss member, provided that each
of the following criteria is met:
i. The attic area is accessible by a pull-down stairway or framed opening
in accordance with Section 1209.2, and
ii. The truss shall have a bottom chord pitch less than 2:12.
iii.Bottom chords of trusses shall be designed for the greater of actual imposed dead load or 10 psf, uniformly distributed over the entire span.
k. Attic spaces served by a fixed stair shall be designed to support the minimum
live load specified for habitable attics and sleeping rooms.
l. Roofs used for other special purposes shall be designed for appropriate loads
as approved by the building official.
1607.7.3 Vehicle barriers. Vehicle barrier systems for passenger cars shall be designed to resist a single load of 6,000
pounds (26.70 kN) applied horizontally in any direction to
the barrier system and shall have anchorage or attachment
capable of transmitting this load to the structure. For design
of the system, the load shall be assumed to act at a minimum
height of 1 foot, 6 inches (457 mm) above the floor or ramp
surface on an area not to exceed 1 square foot (305 mm2),
and is not required to be assumed to act concurrently with
any handraolil or guard loadings specified in the preceding
paragraphs of Section 1607.7.1. Garages accommodating
trucks and buses shall be designed in accordance with an
approved method that contains provision for traffic railings.
1,000
1,000
1,000
—
—
2
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm ,
1 square foot = 0.0929 m2,
1 pound per square foot = 0.0479 kN/m2, 1 pound = 0.004448 kN,
1 pound per cubic foot = 16 kg/m3
a. Floors in garages or portions of buildings used for the storage of motor vehicles shall be designed for the uniformly distributed live loads of Table
1607.1 or the following concentrated loads: (1) for garages restricted to
vehicles accommodating not more than nine passengers, 3,000 pounds acting on an area of 4.5 inches by 4.5 inches; (2) for mechanical parking structures without slab or deck which are used for storing passenger vehicles
only, 2,250 pounds per wheel.
b. The loading applies to stack room floors that support nonmobile, double-faced library bookstacks, subject to the following limitations:
1. The nominal bookstack unit height shall not exceed 90 inches;
2. The nominal shelf depth shall not exceed 12 inches for each face; and
3. Parallel rows of double-faced bookstacks shall be separated by aisles
not less than 36 inches wide.
c. Design in accordance with the ICC Standard on Bleachers, Folding and
Telescopic Seating and Grandstands.
d. Other uniform loads in accordance with an approved method which contains
provisions for truck loadings shall also be considered where appropriate.
e. The concentrated wheel load shall be applied on an area of 20 square inches.
f. Minimum concentrated load on stair treads (on area of 4 square inches) is
300 pounds.
1607.8 Impact loads. The live loads specified in Section
1607.3 include allowance for impact conditions. Provisions
shall be made in the structural design for uses and loads that
involve unusual vibration and impact forces.
1607.8.1 Elevators. Elevator loads shall be increased by
100 percent for impact and the structural supports shall be
designed within the limits of deflection prescribed by
ASME A17.1.
1607.8.2 Machinery. For the purpose of design, the weight
of machinery and moving loads shall be increased as follows to allow for impact: (1) elevator machinery, 100 percent; (2) light machinery, shaft- or motor-driven, 20 percent;
(3) reciprocating machinery or power-driven units, 50 percent; (4) hangers for floors or balconies, 33 percent. Percentages shall be increased where specified by the
manufacturer.
1607.9 Reduction in live loads. Except for roof uniform live
loads, all other minimum uniformly distributed live loads, Lo,
in Table 1607.1 are permitted to be reduced in accordance with
Section 1607.9.1 or 1607.9.2.
2006 INTERNATIONAL BUILDING CODE®
286
16_ibc_2006_pg285-287.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Monday, December 19, 2005 11:21:37 AM
10
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
1607.9.1 General. Subject to the limitations of Sections
1607.9.1.1 through 1607.9.1.4, members for which a value
of KLLAT is 400 square feet (37.16 m2) or more are permitted
to be designed for a reduced live load in accordance with the
following equation:
⎛
15 ⎞
⎟
L = L o ⎜⎜ 0.25 +
⎟
K LL AT ⎠
⎝
1607.9.1.3 Special occupancies. Live loads of 100 psf
(4.79 kN/m2) or less shall not be reduced in public
assembly occupancies.
(Equation 16-24)
⎛
4.57 ⎞
⎟
For SI: L = L o ⎜⎜ 0.25 +
⎟
K LL AT ⎠
⎝
1607.9.1.4 Special structural elements. Live loads
shall not be reduced for one-way slabs except as permitted in Section 1607.9.1.1. Live loads of 100 psf (4.79
kN/m2) or less shall not be reduced for roof members
except as specified in Section 1607.11.2.
where:
L = Reduced design live load per square foot (meter) of
area supported by the member.
Lo = Unreduced design live load per square foot (meter)
of area supported by the member (see Table 1607.1).
KLL = Live load element factor (see Table 1607.9.1).
AT = Tributary area, in square feet (square meters). L shall
not be less than 0.50Lo for members supporting one
floor and L shall not be less than 0.40Lo for members
supporting two or more floors.
TABLE 1607.9.1
LIVE LOAD ELEMENT FACTOR, KLL
ELEMENT
KLL
Interior columns
Exterior columns without cantilever slabs
4
4
Edge columns with cantilever slabs
3
Corner columns with cantilever slabs
Edge beams without cantilever slabs
Interior beams
2
2
2
All other members not identified above including:
Edge beams with cantilever slabs
Cantilever beams
Two-way slabs
Members without provisions for continuous shear
transfer normal to their span
1
1607.9.1.2 Passenger vehicle garages. The live loads
shall not be reduced in passenger vehicle garages except
the live loads for members supporting two or more floors
are permitted to be reduced by a maximum of 20 percent,
but the live load shall not be less than L as calculated in
Section 1607.9.1.
1607.9.2 Alternate floor live load reduction. As an alternative to Section 1607.9.1, floor live loads are permitted to
be reduced in accordance with the following provisions.
Such reductions shall apply to slab systems, beams, girders,
columns, piers, walls and foundations.
1. A reduction shall not be permitted in Group A occupancies.
2. A reduction shall not be permitted where the live load
exceeds 100 psf (4.79 kN/m2) except that the design
live load for members supporting two or more floors
is permitted to be reduced by 20 percent.
3. A reduction shall not be permitted in passenger vehicle parking garages except that the live loads for
members supporting two or more floors are permitted
to be reduced by a maximum of 20 percent.
4. For live loads not exceeding 100 psf (4.79 kN/m2), the
design live load for any structural member supporting
150 square feet (13.94 m2) or more is permitted to be
reduced in accordance with the following equation:
R = 0.08 (A -150)
(Equation 16-25)
For SI: R = 0.861 (A -13.94)
Such reduction shall not exceed the smallest of:
1. 40 percent for horizontal members;
1607.9.1.1 Heavy live loads. Live loads that exceed 100
psf (4.79 kN/m2) shall not be reduced.
2. 60 percent for vertical members; or
3. R as determined by the following equation.
Exceptions:
1. The live loads for members supporting two or
more floors are permitted to be reduced by a
maximum of 20 percent, but the live load shall
not be less than L as calculated in Section
1607.9.1.
2. For uses other than storage, where approved,
additional live load reductions shall be permitted where shown by the registered design
professional that a rational approach has been
used and that such reductions are warranted.
R = 23.1 (1 + D/Lo)
(Equation 16-26)
where:
A = Area of floor supported by the member, square
feet (m2).
D = Dead load per square foot (m2) of area supported.
Lo = Unreduced live load per square foot (m2) of area
supported.
R = Reduction in percent.
➡
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006_pg287.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Thursday, January 05, 2006 1:05:19 PM
287
11
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
R1 = 0.6 for At > 600 square feet
(55.74 m2)
1607.10 Distribution of floor loads. Where uniform floor live
loads are involved in the design of structural members arranged
so as to create continuity, the minimum applied loads shall be
the full dead loads on all spans in combination with the floor
live loads on spans selected to produce the greatest effect at
each location under consideration. It shall be permitted to
reduce floor live loads in accordance with Section 1607.9.
where:
At = Tributary area (span length multiplied by effective
width) in square feet (m2) supported by any structural member, and
1607.11 Roof loads. The structural supports of roofs and marquees shall be designed to resist wind and, where applicable,
snow and earthquake loads, in addition to the dead load of construction and the appropriate live loads as prescribed in this
section, or as set forth in Table 1607.1. The live loads acting on
a sloping surface shall be assumed to act vertically on the horizontal projection of that surface.
(Equation 16-27)
(Equation 16-31)
R2 = 1.2 – 0.05 F for 4 < F < 12
(Equation 16-32)
R2 = 0.6 for F > 12
(Equation 16-33)
F = For a sloped roof, the number of inches of rise per
foot (for SI: F = 0.12 × slope, with slope expressed
as a percentage), or for an arch or dome, the
rise-to-span ratio multiplied by 32.
1607.11.2.2 Special-purpose roofs. Roofs used for
promenade purposes, roof gardens, assembly purposes
or other special purposes shall be designed for a minimum live load as required in Table 1607.1. Such roof live
loads are permitted to be reduced in accordance with
1607.9.
1607.11.2.3 Landscaped roofs. Where roofs are to be
landscaped, the uniform design live load in the landscaped area shall be 20 psf (0.958 kN/m2). The weight of
the landscaping materials shall be considered as dead
load and shall be computed on the basis of saturation of
the soil.
1607.11.2 Reduction in roof live loads. The minimum uniformly distributed roof live loads, Lo, in Table 1607.1 are permitted to be reduced according to the following provisions.
Lr = Lo R1R2
R2 = 1 for F ≤ 4
where:
1607.11.1 Distribution of roof loads. Where uniform roof
live loads are reduced to less than 20 psf (0.96 kN/m2) in
accordance with Section 1607.11.2.1 and are involved in the
design of structural members arranged so as to create continuity, the minimum applied loads shall be the full dead loads
on all spans in combination with the roof live loads on adjacent spans or on alternate spans, whichever produces the
greatest effect. See Section 1607.11.2 for minimum roof
live loads and Section 7.5 of ASCE 7 for partial snow loading.
1607.11.2.1 Flat, pitched and curved roofs. Ordinary
flat, pitched and curved roofs are permitted to be
designed for a reduced roof live load as specified in the
following equation or other controlling combinations of
loads in Section 1605, whichever produces the greater
load. In structures where special scaffolding is used as a
work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equation shall not be used unless
approved by the building official. Greenhouses shall be
designed for a minimum roof live load of 12 psf (0.58
kN/m2).
(Equation 16-30)
1607.11.2.4 Awnings and canopies. Awnings and canopies shall be designed for uniform live loads as required
in Table 1607.1 as well as for snow loads and wind loads
as specified in Sections 1608 and 1609.
1607.12 Crane loads. The crane live load shall be the rated
capacity of the crane. Design loads for the runway beams,
including connections and support brackets, of moving bridge
cranes and monorail cranes shall include the maximum wheel
loads of the crane and the vertical impact, lateral and longitudinal forces induced by the moving crane.
1607.12.1 Maximum wheel load. The maximum wheel
loads shall be the wheel loads produced by the weight of the
bridge, as applicable, plus the sum of the rated capacity and
the weight of the trolley with the trolley positioned on its
runway at the location where the resulting load effect is
maximum.
where: 12 ≤ Lr ≤ 20
For SI: Lr = Lo R1R2
where: 0.58 ≤ Lr ≤ 0.96
Lr = Reduced live load per square foot (m2) of horizontal projection in pounds per square foot (kN/m2).
1607.12.2 Vertical impact force. The maximum wheel
loads of the crane shall be increased by the percentages
shown below to determine the induced vertical impact or
vibration force:
The reduction factors R1 and R2 shall be determined as
follows:
R1 = 1 for At ≤ 200 square feet
(18.58 m2)
(Equation 16-28)
R1 = 1.2 – 0.001At for 200 square
feet < At < 600 square feet
(Equation 16-29)
Pendant-operated bridge cranes (powered) · 10 percent
For SI: 1.2 – 0.011At for 18.58 square meters < At < 55.74
square meters
Bridge cranes or monorail cranes with
hand-geared bridge, trolley and hoist · · · · · 0 percent
Monorail cranes (powered) · · · · · · · · · 25 percent
Cab-operated or remotely operated
bridge cranes (powered) · · · · · · · · · · · 25 percent
2006 INTERNATIONAL BUILDING CODE®
288
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:47 AM
12
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
1607.12.3 Lateral force. The lateral force on crane runway
beams with electrically powered trolleys shall be calculated
as 20 percent of the sum of the rated capacity of the crane
and the weight of the hoist and trolley. The lateral force shall
be assumed to act horizontally at the traction surface of a
runway beam, in either direction perpendicular to the beam,
and shall be distributed according to the lateral stiffness of
the runway beam and supporting structure.
2. A concentrated load of 40 pounds (0.176 kN) applied
to an 8-inch diameter (203 mm) area [50.3 square
inches (32 452 mm2)] of the fabric face at a height of
54 inches (1372 mm) above the floor.
1607.12.4 Longitudinal force. The longitudinal force on
crane runway beams, except for bridge cranes with
hand-geared bridges, shall be calculated as 10 percent of the
maximum wheel loads of the crane. The longitudinal force
shall be assumed to act horizontally at the traction surface of
a runway beam, in either direction parallel to the beam.
1608.1 General. Design snow loads shall be determined in
accordance with Chapter 7 of ASCE 7, but the design roof load
shall not be less than that determined by Section 1607.
Exception: Fabric partitions complying with Section
1607.13.1 shall not be required to resist the minimum horizontal load of 5 psf (0.24 kN/m2).
1607.13.1 Fabric partitions. Fabric partitions that exceed 6
feet (1829 mm) in height, including their finish materials,
shall have adequate strength to resist the following load conditions:
1. A horizontal distributed load of 5 psf (0.24 kN/m2)
applied to the partition framing. The total area used to
determine the distributed load shall be the area of the
fabric face between the framing members to which
the fabric is attached. The total distributed load shall
be uniformly applied to such framing members in
proportion to the length of each member.
1608.2 Ground snow loads. The ground snow loads to be used
in determining the design snow loads for roofs shall be determined in accordance with ASCE 7 or Figure 1608.2 for the
contiguous United States and Table 1608.2 for Alaska.
Site-specific case studies shall be made in areas designated
“CS” in Figure 1608.2. Ground snow loads for sites at elevations above the limits indicated in Figure 1608.2 and for all
sites within the CS areas shall be approved. Ground snow load
determination for such sites shall be based on an extreme value
statistical analysis of data available in the vicinity of the site
using a value with a 2-percent annual probability of being
exceeded (50-year mean recurrence interval). Snow loads are
zero for Hawaii, except in mountainous regions as approved by
the building official.
➡
1607.13 Interior walls and partitions. Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their
finish materials, shall have adequate strength to resist the loads
to which they are subjected but not less than a horizontal load of
5 psf (0.240 kN/m2).
SECTION 1608
SNOW LOADS
SECTION 1609
WIND LOADS
1609.1 Applications. Buildings, structures and parts thereof
shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for
the effect of shielding by other structures.
TABLE 1608.2
GROUND SNOW LOADS, pg , FOR ALASKAN LOCATIONS
LOCATION
POUNDS PER
SQUARE FOOT
LOCATION
POUNDS PER
SQUARE FOOT
LOCATION
POUNDS PER
SQUARE FOOT
Adak
30
Galena
60
Petersburg
150
Anchorage
50
Gulkana
70
St. Paul Islands
40
Angoon
70
Homer
40
Seward
50
Barrow
25
Juneau
60
Shemya
25
Barter Island
35
Kenai
70
Sitka
50
Bethel
40
Kodiak
30
Talkeetna
120
Big Delta
50
Kotzebue
60
Unalakleet
50
Cold Bay
25
McGrath
70
Valdez
160
Cordova
100
Nenana
80
Whittier
300
Fairbanks
60
Nome
70
Wrangell
60
Fort Yukon
60
Palmer
50
Yakutat
150
2
For SI: 1 pound per square foot = 0.0479 kN/m .
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:47 AM
289
13
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1608.2
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)
2006 INTERNATIONAL BUILDING CODE®
290
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:48 AM
14
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1608.2–continued
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:48 AM
291
15
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
nents and cladding loads determined in accordance with the provisions of ASCE 7. Attachment
in accordance with Table 1609.1.2 is permitted for
buildings with a mean roof height of 33 feet (10
058 mm) or less where wind speeds do not exceed
130 mph (57.2 m/s).
1609.1.1 Determination of wind loads. Wind loads on
every building or structure shall be determined in accordance with Chapter 6 of ASCE 7. The type of opening protection required, the basic wind speed and the exposure
category for a site is permitted to be determined in accordance with Section 1609 or ASCE 7. Wind shall be assumed
to come from any horizontal direction and wind pressures
shall be assumed to act normal to the surface considered.
2. Glazing in Occupancy Category I buildings as
defined in Section 1604.5, including greenhouses
that are occupied for growing plants on a production or research basis, without public access shall
be permitted to be unprotected.
1. Subject to the limitations of Section 1609.1.1.1,
the provisions of SBCCI SSTD 10 shall be permitted for applicable Group R-2 and R-3 buildings.
3. Glazing in Occupancy Category II, III or IV buildings located over 60 feet (18 288 mm) above the
ground and over 30 feet (9144 mm) above aggregate surface roofs located within 1,500 feet (458
m) of the building shall be permitted to be unprotected.
2. Subject to the limitations of Section 1609.1.1.1,
residential structures using the provisions of the
AF&PA WFCM.
3. Designs using NAAMM FP 1001.
4. Designs using TIA/EIA-222 for antenna-supporting structures and antennas.
1609.1.2.1 Louvers. Louvers protecting intake and
exhaust ventilation ducts not assumed to be open that are
located within 30 feet (9144 mm) of grade shall meet
requirements of an approved impact-resisting standard
or the Large Missile Test of ASTM E 1996.
1609.1.1.1 Applicability. The provisions of SSTD 10
are applicable only to buildings located within Exposure
B or C as defined in Section 1609.4. The provisions of
SBCCI SSTD 10 and the AF&PA WFCM shall not apply
to buildings sited on the upper half of an isolated hill,
ridge or escarpment meeting the following conditions:
TABLE 1609.1.2
WIND-BORNE DEBRIS PROTECTION FASTENING
SCHEDULE FOR WOOD STRUCTURAL PANELSa,b,c,d
1. The hill, ridge or escarpment is 60 feet (18 288
mm) or higher if located in Exposure B or 30 feet
(9144 mm) or higher if located in Exposure C;
1609.1.2 Protection of openings. In wind-borne debris
regions, glazing in buildings shall be impact-resistant or
protected with an impact-resistant covering meeting the
requirements of an approved impact-resisting standard or
ASTM E 1996 and ASTM E 1886 referenced therein as follows:
1. Glazed openings located within 30 feet (9144 mm) of
grade shall meet the requirements of the Large Missile Test of ASTM E 1996.
2. Glazed openings located more than 30 feet (9144
mm) above grade shall meet the provisions of the
Small Missile Test of ASTM E 1996.
Panel
6 feet
6 feet
Span
Panel
8 feet
16
12
9
No. 8 screws
16
16
12
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.4 N,
1 mile per hour = 0.44 m/s.
a. This table is based on a maximum wind speed (3-second gust) of 130 mph
and mean roof height of 33 feet or less.
b. Fasteners shall be installed at opposing ends of the wood structural panel.
Fasteners shall be located a minimum of 1 inch from the edge of the panel.
c. Fasteners shall be long enough to penetrate through the exterior wall covering a minimum of 1.75 inches into wood wall framing; a minimum of 1.25
inches into concrete block or concrete; or into steel framing by at least three
threads. Fasteners shall be located a minimum of 2.5 inches from the edge of
concrete block or concrete.
d. Where screws are attached to masonry or masonry/stucco, they shall be
attached utilizing vibration-resistant anchors having a minimum withdrawal
capacity of 490 pounds.
1609.2 Definitions. The following words and terms shall, for
the purposes of Section 1609, have the meanings shown herein.
HURRICANE-PRONE REGIONS. Areas vulnerable to
hurricanes defined as:
1. The U. S. Atlantic Ocean and Gulf of Mexico coasts
where the basic wind speed is greater than 90 mph (40
m/s) and
2. Hawaii, Puerto Rico, Guam, Virgin Islands and American Samoa.
WIND-BORNE DEBRIS REGION. Portions of hurricane-prone regions that are within 1 mile (1.61 km) of the
coastal mean high water line where the basic wind speed is 110
mph (48 m/s) or greater; or portions of hurricane-prone regions
2006 INTERNATIONAL BUILDING CODE®
292
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:48 AM
4 feet
Span
No. 6 screws
Exceptions:
1. Wood structural panels with a minimum thickness
of 7/16 inch (11.1 mm) and maximum panel span of
8 feet (2438 mm) shall be permitted for opening
protection in one- and two-story buildings. Panels
shall be precut so that they shall be attached to the
framing surrounding the opening containing the
product with the glazed opening. Panels shall be
secured with the attachment hardware provided.
Attachments shall be designed to resist the compo-
Panel Span
4 feet
16
➡
➡
3. The hill, ridge or escarpment is unobstructed
upwind by other such topographic features for a distance from the high point of 50 times the height of
the hill or 1 mile (1.61 km), whichever is greater.
FASTENER SPACING (inches)
FASTENER
TYPE
➡
2. The maximum average slope of the hill exceeds 10
percent; and
➡
Exceptions:
➡
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
where the basic wind speed is 120 mph (53 m/s) or greater; or
Hawaii.
1609.4.2 Surface roughness categories. A ground surface
roughness within each 45-degree (0.79 rad) sector shall be
determined for a distance upwind of the site as defined in
Section 1609.4.3 from the categories defined below, for the
purpose of assigning an exposure category as defined in
Section 1609.4.3.
➡ 1609.3 Basic wind speed. The basic wind speed, in mph, for
the determination of the wind loads shall be determined by Figure 1609. Basic wind speed for the special wind regions indicated, near mountainous terrain and near gorges shall be in
accordance with local jurisdiction requirements. Basic wind
speeds determined by the local jurisdiction shall be in accordance with Section 6.5.4 of ASCE 7.
Surface Roughness B. Urban and suburban areas,
wooded areas or other terrain with numerous closely
spaced obstructions having the size of single-family
dwellings or larger.
In nonhurricane-prone regions, when the basic wind speed is
estimated from regional climatic data, the basic wind speed
shall be not less than the wind speed associated with an annual
probability of 0.02 (50-year mean recurrence interval), and the
estimate shall be adjusted for equivalence to a 3-second gust
wind speed at 33 feet (10 m) above ground in Exposure Category C. The data analysis shall be performed in accordance
with Section 6.5.4.2 of ASCE 7.
Surface Roughness C. Open terrain with scattered
obstructions having heights generally less than 30 feet
(9144 mm). This category includes flat open country,
grasslands, and all water surfaces in hurricane-prone
regions.
1609.3.1 Wind speed conversion. When required, the
3-second gust basic wind speeds of Figure 1609 shall be
converted to fastest-mile wind speeds, Vfm, using Table
1609.3.1 or Equation 16-34.
(V3 S − 10. 5)
1.05
1609.4.3 Exposure categories. An exposure category shall
be determined in accordance with the following:
Exposure B. Exposure B shall apply where the ground
surface roughness condition, as defined by Surface
Roughness B, prevails in the upwind direction for a distance of at least 2,600 feet (792 m) or 20 times the height
of the building, whichever is greater.
(Equation 16-34)
where:
V3S = 3-second gust basic wind speed from Figure 1609.
Exception: For buildings whose mean roof height is
less than or equal to 30 feet (9144 mm), the upwind distance is permitted to be reduced to 1,500 feet (457 m).
1609.4 Exposure category. For each wind direction considered, an exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for
the site at which the building or structure is to be constructed.
Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well
as from constructed features.
1609.4.1 Wind directions and sectors. For each selected
wind direction at which the wind loads are to be evaluated,
the exposure of the building or structure shall be determined
for the two upwind sectors extending 45 degrees (0.79 rad)
either side of the selected wind direction. The exposures in
these two sectors shall be determined in accordance with
Sections 1609.4.2 and 1609.4.3 and the exposure resulting
in the highest wind loads shall be used to represent winds
from that direction.
Exposure C. Exposure C shall apply for all cases where
Exposures B or D do not apply.
Exposure D. Exposure D shall apply where the ground
surface roughness, as defined by Surface Roughness D,
prevails in the upwind direction for a distance of at least
5,000 feet (1524 m) or 20 times the height of the building, whichever is greater. Exposure D shall extend inland
from the shoreline for a distance of 600 feet (183 m) or 20
times the height of the building, whichever is greater.
1609.5 Roof systems.
1609.5.1 Roof deck. The roof deck shall be designed to
withstand the wind pressures determined in accordance
with ASCE 7.
TABLE 1609.3.1
EQUIVALENT BASIC WIND SPEEDSa,b,c
V3S
85
90
100
105
110
120
125
130
140
145
150
160
170
Vfm
71
76
85
90
95
104
109
114
123
128
133
142
152
For SI: 1 mile per hour = 0.44 m/s.
a. Linear interpolation is permitted.
b. V3S is the 3-second gust wind speed (mph).
c. Vfm is the fastest mile wind speed (mph).
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006_update.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Thursday, December 08, 2005 8:28:43 AM
293
17
➡
Vfm =
Surface Roughness D. Flat, unobstructed areas and
water surfaces outside hurricane-prone regions. This category includes smooth mud flats, salt flats and unbroken
ice.
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1609
BASIC WIND SPEED (3-SECOND GUST)
2006 INTERNATIONAL BUILDING CODE®
294
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:53 AM
18
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1609—continued
BASIC WIND SPEED (3-SECOND GUST)
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:56 AM
295
19
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1609–continued
BASIC WIND SPEED (3-SECOND GUST)
WESTERN GULF OF MEXICO HURRICANE COASTLINE
2006 INTERNATIONAL BUILDING CODE®
296
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:49:59 AM
20
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1609–continued
BASIC WIND SPEED (3-SECOND GUST)
EASTERN GULF OF MEXICO AND SOUTHEASTERN U.S. HURRICANE COASTLINE
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:02 AM
297
21
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1609–continued
BASIC WIND SPEED (3-SECOND GUST)
MID AND NORTHERN ATLANTIC HURRICANE COASTLINE
2006 INTERNATIONAL BUILDING CODE®
298
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:05 AM
22
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
Concrete and clay roof tiles complying with the following limitations shall be designed to withstand the aerodynamic uplift moment as determined by this section.
1609.5.2 Roof coverings. Roof coverings shall comply
with Section 1609.5.1.
Exception: Rigid tile roof coverings that are air permeable and installed over a roof deck complying with Section 1609.5.1 are permitted to be designed in accordance
with Section 1609.5.3.
1. The roof tiles shall be either loose laid on battens,
mechanically fastened, mortar set or adhesive set.
2. The roof tiles shall be installed on solid sheathing
which has been designed as components and cladding.
Asphalt shingles installed over a roof deck complying
with Section 1609.5.1 shall be tested to determine the resistance of the sealant to uplift forces using ASTM D 6381.
3. An underlayment shall be installed in accordance
with Chapter 15.
Asphalt shingles installed over a roof deck complying
with Section 1609.5.1 are permitted to be designed using
UL 2390 to determine appropriate uplift and force coefficients applied to the shingle.
4. The tile shall be single lapped interlocking with a
minimum head lap of not less than 2 inches (51
mm).
1609.5.3 Rigid tile. Wind loads on rigid tile roof coverings
shall be determined in accordance with the following equation:
5. The length of the tile shall be between 1.0 and 1.75
feet (305 mm and 533 mm).
Ma = qhCLbLLa[1.0 – GCp]
6. The exposed width of the tile shall be between 0.67
and 1.25 feet (204 mm and 381 mm).
For SI: Ma =
[
q h C L bLL a 1.0 − GC p
(Equation 16-35)
]
7. The maximum thickness of the tail of the tile shall not
exceed 1.3 inches (33 mm).
1, 000
8. Roof tiles using mortar set or adhesive set systems
shall have at least two-thirds of the tile’s area free of
mortar or adhesive contact.
where:
b
CL
= Exposed width, feet (mm) of the roof tile.
= Lift coefficient. The lift coefficient for concrete and
clay tile shall be 0.2 or shall be determined by test in
accordance with Section 1715.2.
SECTION 1610
SOIL LATERAL LOADS
GCp = Roof pressure coefficient for each applicable roof
zone determined from Chapter 6 of ASCE 7. Roof
coefficients shall not be adjusted for internal pressure.
L = Length, feet (mm) of the roof tile.
La = Moment arm, feet (mm) from the axis of rotation to
the point of uplift on the roof tile. The point of uplift
shall be taken at 0.76L from the head of the tile and
the middle of the exposed width. For roof tiles with
nails or screws (with or without a tail clip), the axis
of rotation shall be taken as the head of the tile for
direct deck application or as the top edge of the batten for battened applications. For roof tiles fastened
only by a nail or screw along the side of the tile, the
axis of rotation shall be determined by testing. For
roof tiles installed with battens and fastened only by
a clip near the tail of the tile, the moment arm shall
be determined about the top edge of the batten with
consideration given for the point of rotation of the
tiles based on straight bond or broken bond and the
tile profile.
Ma = Aerodynamic uplift moment, feet-pounds (N-mm)
acting to raise the tail of the tile.
qh = Wind velocity pressure, psf (kN/m2) determined
from Section 6.5.10 of ASCE 7.
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:06 AM
1610.1 General. Basement, foundation and retaining walls
shall be designed to resist lateral soil loads. Soil loads specified
in Table 1610.1 shall be used as the minimum design lateral soil
loads unless specified otherwise in a soil investigation report
approved by the building official. Basement walls and other
walls in which horizontal movement is restricted at the top shall
be designed for at-rest pressure. Retaining walls free to move
and rotate at the top are permitted to be designed for active
pressure. Design lateral pressure from surcharge loads shall be
added to the lateral earth pressure load. Design lateral pressure
shall be increased if soils with expansion potential are present
at the site.
Exception: Basement walls extending not more than 8 feet
(2438 mm) below grade and supporting flexible floor systems shall be permitted to be designed for active pressure.
SECTION 1611
RAIN LOADS
1611.1 Design rain loads. Each portion of a roof shall be
designed to sustain the load of rainwater that will accumulate
on it if the primary drainage system for that portion is blocked
plus the uniform load caused by water that rises above the inlet
of the secondary drainage system at its design flow.
R = 5.2 (ds + dh)
(Equation 16-36)
299
23
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
For SI: R = 0.0098 (ds + dh)
where:
dh
= Additional depth of water on the undeflected roof
above the inlet of secondary drainage system at its
design flow (i.e., the hydraulic head), in inches (mm).
ds
= Depth of water on the undeflected roof up to the inlet of
secondary drainage system when the primary drainage
system is blocked (i.e., the static head), in inches (mm).
R
= Rain load on the undeflected roof, in psf (kN/m2). When
the phrase “undeflected roof” is used, deflections from
loads (including dead loads) shall not be considered
when determining the amount of rain on the roof.
1611.2 Ponding instability. For roofs with a slope less than 1/4
inch per foot [1.19 degrees (0.0208 rad)], the design calculations shall include verification of adequate stiffness to preclude
progressive deflection in accordance with Section 8.4 of ASCE
7.
1611.3 Controlled drainage. Roofs equipped with hardware
to control the rate of drainage shall be equipped with a secondary drainage system at a higher elevation that limits accumulation of water on the roof above that elevation. Such roofs shall
be designed to sustain the load of rainwater that will accumulate on them to the elevation of the secondary drainage system
plus the uniform load caused by water that rises above the inlet
of the secondary drainage system at its design flow determined
from Section 1611.1. Such roofs shall also be checked for
ponding instability in accordance with Section 1611.2.
SECTION 1612
FLOOD LOADS
1612.1 General. Within flood hazard areas as established in Section 1612.3, all new construction of buildings, structures and
portions of buildings and structures, including substantial
improvement and restoration of substantial damage to buildings
and structures, shall be designed and constructed to resist the
effects of flood hazards and flood loads. For buildings that are
located in more than one flood hazard area, the provisions associated with the most restrictive flood hazard area shall apply.
1612.2 Definitions. The following words and terms shall, for
the purposes of this section, have the meanings shown herein.
BASE FLOOD. The flood having a 1-percent chance of being
equaled or exceeded in any given year.
TABLE 1610.1
SOIL LATERAL LOAD
DESIGN LATERAL SOIL LOADa
(pound per square foot per foot of depth)
UNIFIED SOIL
CLASSIFICATION
Active pressure
At-rest pressure
Well-graded, clean gravels; gravel-sand mixes
GW
30
60
Poorly graded clean gravels; gravel-sand mixes
GP
30
60
Silty gravels, poorly graded gravel-sand mixes
GM
40
60
Clayey gravels, poorly graded gravel-and-clay mixes
GC
45
60
Well-graded, clean sands; gravelly sand mixes
SW
30
60
Poorly graded clean sands; sand-gravel mixes
SP
30
60
Silty sands, poorly graded sand-silt mixes
SM
45
60
SM-SC
45
100
Clayey sands, poorly graded sand-clay mixes
SC
60
100
Inorganic silts and clayey silts
ML
45
100
Mixture of inorganic silt and clay
ML-CL
60
100
Inorganic clays of low to medium plasticity
CL
60
100
Organic silts and silt clays, low plasticity
OL
Note b
Note b
Inorganic clayey silts, elastic silts
MH
Note b
Note b
Inorganic clays of high plasticity
CH
Note b
Note b
Organic clays and silty clays
OH
Note b
Note b
DESCRIPTION OF BACKFILL MATERIALc
Sand-silt clay mix with plastic fines
For SI: 1 pound per square foot per foot of depth = 0.157 kPa/m, 1 foot = 304.8 mm.
a. Design lateral soil loads are given for moist conditions for the specified soils at their optimum densities. Actual field conditions shall govern. Submerged or saturated soil pressures shall include the weight of the buoyant soil plus the hydrostatic loads.
b. Unsuitable as backfill material.
c. The definition and classification of soil materials shall be in accordance with ASTM D 2487.
2006 INTERNATIONAL BUILDING CODE®
300
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:06 AM
24
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
BASE FLOOD ELEVATION. The elevation of the base
flood, including wave height, relative to the National Geodetic
Vertical Datum (NGVD), North American Vertical Datum
(NAVD) or other datum specified on the Flood Insurance Rate
Map (FIRM).
FLOOD INSURANCE RATE MAP (FIRM). An official
map of a community on which the Federal Emergency Management Agency (FEMA) has delineated both the special flood
hazard areas and the risk premium zones applicable to the community.
BASEMENT. The portion of a building having its floor
subgrade (below ground level) on all sides.
FLOOD INSURANCE STUDY. The official report provided
by the Federal Emergency Management Agency containing the
Flood Insurance Rate Map (FIRM), the Flood Boundary and
Floodway Map (FBFM), the water surface elevation of the base
flood and supporting technical data.
DESIGN FLOOD. The flood associated with the greater of
the following two areas:
1. Area with a flood plain subject to a 1-percent or greater
chance of flooding in any year; or
FLOODWAY. The channel of the river, creek or other watercourse and the adjacent land areas that must be reserved in
order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.
2. Area designated as a flood hazard area on a community’s
flood hazard map, or otherwise legally designated.
DESIGN FLOOD ELEVATION. The elevation of the
“design flood,” including wave height, relative to the datum
specified on the community’s legally designated flood hazard
map. In areas designated as Zone AO, the design flood elevation shall be the elevation of the highest existing grade of the
building’s perimeter plus the depth number (in feet) specified
on the flood hazard map. In areas designated as Zone AO where
a depth number is not specified on the map, the depth number
shall be taken as being equal to 2 feet (610 mm).
DRY FLOODPROOFING. A combination of design modifications that results in a building or structure, including the
attendant utility and sanitary facilities, being water tight with
walls substantially impermeable to the passage of water and
with structural components having the capacity to resist loads
as identified in ASCE 7.
EXISTING CONSTRUCTION. Any buildings and structures for which the “start of construction” commenced before
the effective date of the community’s first flood plain management code, ordinance or standard. “Existing construction” is
also referred to as “existing structures.”
EXISTING STRUCTURE. See “Existing construction.”
FLOOD or FLOODING. A general and temporary condition
of partial or complete inundation of normally dry land from:
1. The overflow of inland or tidal waters.
2. The unusual and rapid accumulation or runoff of surface
waters from any source.
FLOOD DAMAGE-RESISTANT MATERIALS. Any construction material capable of withstanding direct and prolonged contact with floodwaters without sustaining any
damage that requires more than cosmetic repair.
SPECIAL FLOOD HAZARD AREA. The land area subject
to flood hazards and shown on a Flood Insurance Rate Map or
other flood hazard map as Zone A, AE, A1-30, A99, AR, AO,
AH, V, VO, VE or V1-30.
START OF CONSTRUCTION. The date of permit issuance
for new construction and substantial improvements to existing
structures, provided the actual start of construction, repair,
reconstruction, rehabilitation, addition, placement or other
improvement is within 180 days after the date of issuance. The
actual start of construction means the first placement of permanent construction of a building (including a manufactured
home) on a site, such as the pouring of a slab or footings, installation of pilings or construction of columns.
Permanent construction does not include land preparation
(such as clearing, excavation, grading or filling), the installation of streets or walkways, excavation for a basement, footings, piers or foundations, the erection of temporary forms or
the installation of accessory buildings such as garages or sheds
not occupied as dwelling units or not part of the main building.
For a substantial improvement, the actual “start of construction” means the first alteration of any wall, ceiling, floor or
other structural part of a building, whether or not that alteration
affects the external dimensions of the building.
SUBSTANTIAL DAMAGE. Damage of any origin sustained
by a structure whereby the cost of restoring the structure to its
before-damaged condition would equal or exceed 50 percent of
the market value of the structure before the damage occurred.
FLOOD HAZARD AREA. The greater of the following two
areas:
1. The area within a flood plain subject to a 1-percent or
greater chance of flooding in any year.
2. The area designated as a flood hazard area on a community’s flood hazard map, or otherwise legally designated.
FLOOD HAZARD AREA SUBJECT TO HIGH VELOCITY WAVE ACTION. Area within the flood hazard area that
is subject to high velocity wave action, and shown on a Flood
Insurance Rate Map (FIRM) or other flood hazard map as Zone
V, VO, VE or V1-30.
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:06 AM
LOWEST FLOOR. The floor of the lowest enclosed area,
including basement, but excluding any unfinished or
flood-resistant enclosure, usable solely for vehicle parking,
building access or limited storage provided that such enclosure
is not built so as to render the structure in violation of this section.
SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, rehabilitation, addition or improvement of a building or
structure, the cost of which equals or exceeds 50 percent of the
market value of the structure before the improvement or repair
is started. If the structure has sustained substantial damage, any
repairs are considered substantial improvement regardless of
the actual repair work performed. The term does not, however,
include either:
1. Any project for improvement of a building required to
correct existing health, sanitary or safety code violations
301
25
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
identified by the building official and that are the minimum necessary to assure safe living conditions.
2.3. For breakaway walls designed to resist a nominal
load of less than 10 psf (0.48 kN/m2) or more than
20 psf (0.96 kN/m2), construction documents
shall include a statement that the breakaway wall
is designed in accordance with ASCE 24.
1612.3 Establishment of flood hazard areas. To establish
flood hazard areas, the governing body shall adopt a flood hazard map and supporting data. The flood hazard map shall
include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency in an
engineering report entitled “The Flood Insurance Study for
[INSERT NAME OF JURISDICTION],” dated [INSERT DATE OF ISSUANCE], as amended or revised with the accompanying Flood
Insurance Rate Map (FIRM) and Flood Boundary and Floodway
Map (FBFM) and related supporting data along with any revisions thereto. The adopted flood hazard map and supporting data
are hereby adopted by reference and declared to be part of this
section.
SECTION 1613
EARTHQUAKE LOADS
1613.1 Scope. Every structure, and portion thereof, including
nonstructural components that are permanently attached to
structures and their supports and attachments, shall be
designed and constructed to resist the effects of earthquake
motions in accordance with ASCE 7, excluding Chapter 14 and
Appendix 11A. The seismic design category for a structure is
permitted to be determined in accordance with Section 1613 or
ASCE 7.
Exceptions:
1612.4 Design and construction. The design and construction
of buildings and structures located in flood hazard areas,
including flood hazard areas subject to high velocity wave
action, shall be in accordance with ASCE 24.
1. Detached one- and two-family dwellings, assigned to
Seismic Design Category A, B or C, or located where
the mapped short-period spectral response acceleration, SS, is less than 0.4 g.
1612.5 Flood hazard documentation. The following documentation shall be prepared and sealed by a registered design
professional and submitted to the building official:
2. The seismic-force-resisting system of wood-frame
buildings that conform to the provisions of Section
2308 are not required to be analyzed as specified in
this section.
1. For construction in flood hazard areas not subject to
high-velocity wave action:
3. Agricultural storage structures intended only for incidental human occupancy.
1.1. The elevation of the lowest floor, including the
basement, as required by the lowest floor elevation inspection in Section 109.3.3.
1.2. For fully enclosed areas below the design flood
elevation where provisions to allow for the automatic entry and exit of floodwaters do not meet
the minimum requirements in Section 2.6.2.1 of
ASCE 24, construction documents shall include
a statement that the design will provide for equalization of hydrostatic flood forces in accordance
with Section 2.6.2.2 of ASCE 24.
1.3. For dry floodproofed nonresidential buildings,
construction documents shall include a statement
that the dry floodproofing is designed in accordance with ASCE 24.
4. Structures that require special consideration of their
response characteristics and environment that are not
addressed by this code or ASCE 7 and for which other
regulations provide seismic criteria, such as vehicular
bridges, electrical transmission towers, hydraulic
structures, buried utility lines and their appurtenances
and nuclear reactors.
1613.2 Definitions. The following words and terms shall, for
the purposes of this section, have the meanings shown herein.
DESIGN EARTHQUAKE GROUND MOTION. The earthquake ground motion that buildings and structures are specifically proportioned to resist in Section 1613.
2. For construction in flood hazard areas subject to
high-velocity wave action:
MAXIMUM CONSIDERED EARTHQUAKE GROUND
MOTION. The most severe earthquake effects considered by
this code.
2.1. The elevation of the bottom of the lowest horizontal structural member as required by the lowest floor elevation inspection in Section 109.3.3.
MECHANICAL SYSTEMS. For the purposes of determining seismic loads in ASCE 7, mechanical systems shall include
plumbing systems as specified therein.
2.2. Construction documents shall include a statement that the building is designed in accordance
with ASCE 24, including that the pile or column
foundation and building or structure to be
attached thereto is designed to be anchored to
resist flotation, collapse and lateral movement
due to the effects of wind and flood loads acting
simultaneously on all building components, and
other load requirements of Chapter 16.
ORTHOGONAL. To be in two horizontal directions, at 90
degrees (1.57 rad) to each other.
SEISMIC DESIGN CATEGORY. A classification assigned
to a structure based on its occupancy category and the severity
of the design earthquake ground motion at the site.
SEISMIC-FORCE-RESISTING SYSTEM. That part of the
structural system that has been considered in the design to provide the required resistance to the prescribed seismic forces.
2006 INTERNATIONAL BUILDING CODE®
302
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:07 AM
26
➡
2. Any alteration of a historic structure provided that the
alteration will not preclude the structure’s continued designation as a historic structure.
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
D, E or F in accordance with Table 1613.5.2. When the soil
properties are not known in sufficient detail to determine the
site class, Site Class D shall be used unless the building official or geotechnical data determines that Site Class E or F
soil is likely to be present at the site.
SITE CLASS. A classification assigned to a site based on the
types of soils present and their engineering properties as
defined in Section 1613.5.2.
SITE COEFFICIENTS. The values of Fa and Fv indicated in
Tables 1613.5.3(1) and 1613.5.3(2), respectively.
1613.5.3 Site coefficients and adjusted maximum considered earthquake spectral response acceleration
parameters. The maximum considered earthquake spectral
response acceleration for short periods, SMS, and at 1-second
period, SM1, adjusted for site class effects shall be determined by Equations 16-37 and 16-38, respectively:
1613.3 Existing buildings. Additions, alterations, modification, or change of occupancy of existing buildings shall be in
accordance with Sections 3403.2.3 and 3406.4.
1613.4 Special inspections. Where required by Section
1705.3, the statement of special inspections shall include the
special inspections required by Section 1705.3.1.
1613.5 Seismic ground motion values. Seismic ground
motion values shall be determined in accordance with this section.
SMS = FaSs
(Equation 16-37)
SM1 = Fv S1
(Equation 16-38)
1613.5.1 Mapped acceleration parameters. The parameters Ss and S1 shall be determined from the 0.2 and 1-second
spectral response accelerations shown on Figures 1613.5(1)
through 1613.5(14). Where S1 is less than or equal to 0.04
and Ss is less than or equal to 0.15, the structure is permitted
to be assigned to Seismic Design Category A.
where:
1613.5.2 Site class definitions. Based on the site soil properties, the site shall be classified as either Site Class A, B, C,
S1 = The mapped spectral accelerations for a 1-second
period as determined in Section 1613.5.1.
Fa = Site coefficient defined in Table 1613.5.3(1).
Fv = Site coefficient defined in Table 1613.5.3(2).
SS = The mapped spectral accelerations for short periods
as determined in Section 1613.5.1.
TABLE 1613.5.2
SITE CLASS DEFINITIONS
AVERAGE PROPERTIES IN TOP 100 feet, SEE SECTION 1613.5.5
SITE
CLASS
SOIL PROFILE
NAME
Soil shear wave velocity, v S , (ft/s)
A
Hard rock
v s > 5,000
N/A
N/A
B
Rock
2,500 < v s ≤ 5,000
N/A
N/A
C
Very dense soil and soft
rock
1,200 < v s ≤ 2,500
N > 50
s u ≥ 2,000
D
Stiff soil profile
600 ≤ v s ≤ 1,200
15 ≤ N ≤ 50
1,000 ≤ s u ≤ 2,000
E
Soft soil profile
v s < 600
N < 15
s u < 1,000
Standard penetration resistance, N Soil undrained shear strength, s u , (psf)
Any profile with more than 10 feet of soil having the following characteristics:
1. Plasticity index PI > 20,
E
—
2. Moisture content w ≥ 40%, and
3. Undrained shear strength s u < 500 psf
F
—
Any profile containing soils having one or more of the following characteristics:
1. Soils vulnerable to potential failure or collapse under seismic loading such as liquefiable
soils, quick and highly sensitive clays, collapsible weakly cemented soils.
2. Peats and/or highly organic clays (H > 10 feet of peat and/or highly organic clay where
H = thickness of soil)
3. Very high plasticity clays (H >25 feet with plasticity index PI >75)
4. Very thick soft/medium stiff clays (H >120 feet)
For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kPa. N/A = Not applicable
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:07 AM
303
27
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
TABLE 1613.5.3(1)
VALUES OF SITE COEFFICIENT Fa a
SITE
CLASS
MAPPED SPECTRAL RESPONSE ACCELERATION AT SHORT PERIOD
Ss
0.25
Ss = 0.50
Ss = 0.75
Ss = 1.00
Ss
1.25
A
0.8
0.8
0.8
0.8
0.8
B
1.0
1.0
1.0
1.0
1.0
C
1.2
1.2
1.1
1.0
1.0
D
1.6
1.4
1.2
1.1
1.0
E
2.5
1.7
1.2
0.9
0.9
F
Note b
Note b
Note b
Note b
Note b
a. Use straight-line interpolation for intermediate values of mapped spectral response acceleration at short period, Ss.
b. Values shall be determined in accordance with Section 11.4.7 of ASCE 7.
TABLE 1613.5.3(2)
VALUES OF SITE COEFFICIENT FV a
SITE
CLASS
MAPPED SPECTRAL RESPONSE ACCELERATION AT 1-SECOND PERIOD
S1
0.1
S1 = 0.2
S1 = 0.3
S1 = 0.4
S1
0.5
A
0.8
0.8
0.8
0.8
0.8
B
1.0
1.0
1.0
1.0
1.0
C
1.7
1.6
1.5
1.4
1.3
D
2.4
2.0
1.8
1.6
1.5
E
3.5
3.2
2.8
2.4
2.4
F
Note b
Note b
Note b
Note b
Note b
a. Use straight-line interpolation for intermediate values of mapped spectral response acceleration at 1-second period, S1.
b. Values shall be determined in accordance with Section 11.4.7 of ASCE 7.
1613.5.4 Design spectral response acceleration parameters. Five-percent damped design spectral response acceleration at short periods, SDS, and at 1-second period, SD1, shall
be determined from Equations 16-39 and 16-40, respectively:
2
SDS = SMS
3
(Equation 16-39)
2
SD1 = SM1
3
(Equation 16-40)
1613.5.5 Site classification for seismic design. Site classification for Site Class C, D or E shall be determined from
Table 1613.5.5.
The notations presented below apply to the upper 100 feet
(30 480 mm) of the site profile. Profiles containing distinctly different soil and/or rock layers shall be subdivided
into those layers designated by a number that ranges from 1
to n at the bottom where there is a total of n distinct layers in
the upper 100 feet (30 480 mm). The symbol i then refers to
any one of the layers between 1 and n.
where:
vsi = The shear wave velocity in feet per second (m/s).
di = The thickness of any layer between 0 and 100 feet (30
480 mm).
where:
where:
➡
SMS = The maximum considered earthquake spectral
response accelerations for short period as determined in Section 1613.5.3.
SM1 = The maximum considered earthquake spectral
response accelerations for 1-second period as determined in Section 1613.5.3.
n
vs =
n
di
∑
i =1 v si
(Equation 16-41)
2006 INTERNATIONAL BUILDING CODE®
304
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:08 AM
di
∑
i =1
28
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
n
k = The number of cohesive soil layers in the top 100 feet
(30 480 mm).
di = 100 feet (30 480 mm)
∑
i =1
Ni is the Standard Penetration Resistance (ASTM D
1586) not to exceed 100 blows/foot (305 mm) as directly
measured in the field without corrections. When refusal is
met for a rock layer, Ni shall be taken as 100 blows/foot (305
mm).
n
N=
di
∑
i =1
(Equation 16-42)
di
∑=1 N
i
i
where Ni and di in Equation 16-42 are for cohesionless
soil, cohesive soil and rock layers.
(Equation 16-43)
The hard rock category, Site Class A, shall be supported
by shear wave velocity measurements either on site or on
profiles of the same rock type in the same formation with an
equal or greater degree of weathering and fracturing. Where
hard rock conditions are known to be continuous to a depth
of 100 feet (30 480 mm), surficial shear wave velocity measurements are permitted to be extrapolated to assess vs.
m
di = ds
∑
i =1
Use di and Ni for cohesionless soil layers only in Equation
16-43.
ds = The total thickness of cohesionless soil layers in the
top 100 feet (30 480 mm).
m = The number of cohesionless soil layers in the top 100
feet (30 480 mm).
sui = The undrained shear strength in psf (kPa), not to
exceed 5,000 psf (240 kPa), ASTM D 2166 or D
2850.
dc
d
∑=1 s i
i
ui
where:
su =
Where a site does not qualify under the criteria for Site
Class F and there is a total thickness of soft clay greater than
10 feet (3048 mm) where a soft clay layer is defined by: su <
500 psf (24 kPa), w ≥ 40 percent, and PI > 20, it shall be classified as Site Class E.
The shear wave velocity for rock, Site Class B, shall be
either measured on site or estimated by a geotechnical engineer or engineering geologist/seismologist for competent
rock with moderate fracturing and weathering. Softer and
more highly fractured and weathered rock shall either be
measured on site for shear wave velocity or classified as Site
Class C.
n
d
N ch = m s
d
∑=1 N i
i
i
where:
PI = The plasticity index, ASTM D 4318.
w = The moisture content in percent, ASTM D 2216.
The rock categories, Site Classes A and B, shall not be
used if there is more than 10 feet (3048 mm) of soil between
the rock surface and the bottom of the spread footing or mat
foundation.
1613.5.5.1 Steps for classifying a site.
1. Check for the four categories of Site Class F requiring site-specific evaluation. If the site corresponds
to any of these categories, classify the site as Site
Class F and conduct a site-specific evaluation.
(Equation 16-44)
k
2. Check for the existence of a total thickness of soft
clay > 10 feet (3048 mm) where a soft clay layer is
defined by: su < 500 psf (24 kPa), w ≥ 40 percent
and PI > 20. If these criteria are satisfied, classify
the site as Site Class E.
k
di = dc
∑
i =1
3. Categorize the site using one of the following three
methods with v s , N, and s u and computed in all
cases as specified.
dc = The total thickness of cohesive soil layers in the top
100 feet (30 480 mm).
TABLE 1613.5.5
SITE CLASSIFICATIONa
SITE CLASS
vs
N or N ch
su
E
< 600 ft/s
< 15
< 1,000 psf
D
600 to 1,200 ft/s
15 to 50
1,000 to 2,000 psf
C
1,200 to 2,500 ft/s
> 50
> 2,000
For SI: 1 foot per second = 304.8 mm per second, 1 pound per square foot = 0.0479kN/m2.
a. If the su method is used and the N ch and su criteria differ, select the category with the softer soils (for example, use Site Class E instead of D).
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:08 AM
305
29
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
3.1. v s for the top 100 feet (30 480 mm) (v s
method).
1613.5.6.1 Alternative seismic design category determination. Where S1 is less than 0.75, the seismic design
category is permitted to be determined from Table
1613.5.6(1) alone when all of the following apply:
3.2. N ch for the top 100 feet (30 480 mm) (N
method).
1. In each of the two orthogonal directions, the
approximate fundamental period of the structure,
Ta, in each of the two orthogonal directions determined in accordance with Section 12.8.2.1 of
ASCE 7, is less than 0.8 Ts determined in accordance with Section 11.4.5 of ASCE 7.
1613.5.6 Determination of seismic design category.
Occupancy Category I, II or III structures located where the
mapped spectral response acceleration parameter at 1-second period, Sl, is greater than or equal to 0.75 shall be
assigned to Seismic Design Category E. Occupancy Category IV structures located where the mapped spectral
response acceleration parameter at 1-second period, S1, is
greater than or equal to 0.75 shall be assigned to Seismic
Design Category F. All other structures shall be assigned to
a seismic design category based on their occupancy category and the design spectral response acceleration coefficients, SDS and SD1, determined in accordance with Section
1613.5.4 or the site-specific procedures of ASCE 7. Each
building and structure shall be assigned to the more severe
seismic design category in accordance with Table
1613.5.6(1) or 1613.5.6(2), irrespective of the fundamental
period of vibration of the structure, T.
2. In each of the two orthogonal directions, the fundamental period of the structure used to calculate
the story drift is less than Ts.
TABLE 1613.5.6(1)
SEISMIC DESIGN CATEGORY BASED ON
SHORT-PERIOD RESPONSE ACCELERATIONS
3. Equation 12.8-2 of ASCE 7 is used to determine
the seismic response coefficient, Cs.
4. The diaphragms are rigid as defined in Section
12.3.1 in ASCE 7 or for diaphragms that are flexible, the distance between vertical elements of the
seismic-force-resisting system does not exceed 40
feet (12 192 mm).
1613.5.6.2 Simplified design procedure. Where the
alternate simplified design procedure of ASCE 7 is used,
the seismic design category shall be determined in accordance with ASCE 7.
1613.6 Alternatives to ASCE 7. The provisions of Section
1613.6 shall be permitted as alternatives to the relevant provisions of ASCE 7.
1613.6.1 Assumption of flexible diaphragm. Add the following text at the end of Section 12.3.1.1 of ASCE 7:
OCCUPANCY CATEGORY
VALUE OF SDS
I or II
III
IV
SDS < 0.167g
A
A
A
0.167g ≤ SDS < 0.33g
B
B
C
0.33g ≤ SDS < 0.50g
C
C
D
0.50g ≤ SDS
D
D
D
➡
Diaphragms constructed of wood structural panels or
untopped steel decking shall also be permitted to be idealized as flexible, provided all of the following conditions are
met:
1. Toppings of concrete or similar materials are not
placed over wood structural panel diaphragms except
for nonstructural toppings no greater than 11/2 inches
(38 mm) thick.
TABLE 1613.5.6(2)
SEISMIC DESIGN CATEGORY BASED ON
1-SECOND PERIOD RESPONSE ACCELERATION
2. Each line of vertical elements of the lateral-force-resisting system complies with the allowable story drift of Table 12.12-1.
OCCUPANCY CATEGORY
VALUE OF SD1
I or II
III
IV
SD1 < 0.067g
A
A
A
0.067g ≤ SD1 < 0.133g
B
B
C
0.133g ≤ SD1 < 0.20g
C
C
D
0.20g ≤ SD1
D
D
D
3. Vertical elements of the lateral-force-resisting system
are light-framed walls sheathed with wood structural
panels rated for shear resistance or steel sheets.
4. Portions of wood structural panel diaphragms that
cantilever beyond the vertical elements of the lateral-force-resisting system are designed in accordance with Section 2305.2.5 of the International
Building Code.
➡
2006 INTERNATIONAL BUILDING CODE®
306
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:08 AM
30
➡
➡
3.3. N for cohesionless soil layers (PI < 20) in
the top 100 feet (30 480 mm) and average, s u for cohesive soil layers (PI > 20)
in the top 100 feet (30 480 mm) ( s u
method).
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
1613.6.2 Additional seismic-force-resisting systems for
seismically isolated structures. Add the following exception to the end of Section 17.5.4.2 of ASCE 7:
Exception: For isolated structures designed in accordance with this standard, the Structural System Limitations and the Building Height Limitations in Table
12.2-1 for ordinary steel concentrically braced frames
(OCBFs) as defined in Chapter 11 and ordinary moment
frames (OMFs) as defined in Chapter 11 are permitted to
be taken as 160 feet (48 768 mm) for structures assigned
to Seismic Design Category D, E or F, provided that the
following conditions are satisfied:
1. The value of RI as defined in Chapter 17 is taken as
1.
2. For OMFs and OCBFs, design is in accordance
with AISC 341.
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:09 AM
307
31
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1613.5(1)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF
0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B
2006 INTERNATIONAL BUILDING CODE®
308
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:18 AM
32
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1613.5(1)—continued
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF
0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:23 AM
309
33
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1613.5(2)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES
OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B
2006 INTERNATIONAL BUILDING CODE®
310
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:31 AM
34
Color profile: Generic CMYK printer profile
Composite Default screen
STRUCTURAL DESIGN
FIGURE 1613.5(2)—continued
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES
OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B
2006 INTERNATIONAL BUILDING CODE®
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:36 AM
311
35
Color profile: Generic CMYK printer profile
Composite Default screen
FIGURE 1613.5(3)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF
0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B
STRUCTURAL DESIGN
2006 INTERNATIONAL BUILDING CODE®
312
16_ibc_2006.prn
M:\data\CODES\2006 I-Codes\Building\Final VP_Chgo\16_ibc_2006.vp
Wednesday, December 07, 2005 10:50:39 AM
36