The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meanings shown herein.
EXTERIOR INSULATION AND FINISH SYSTEMS (EIFS). EIFS are nonstructural, nonload-bearing, exterior wall cladding systems that consist of an insulation board attached either adhesively or mechanically, or both, to the substrate; an integrally reinforced base coat and a textured protective finish coat.
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.
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 discrete 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) SYSTEM. An exterior wall covering fabricated using MCM in a specific assembly including joints, seams, attachments, substrate, framing and other details as appropriate to a particular design.
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 further intruding into the exterior wall assembly.
Exterior walls shall provide the building with a weather-resistant exterior wall envelope. The exterior wall envelope shall include flashing, as described in Section 1405.4. 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 Section 1405.3.
- A weather-resistant exterior wall envelope shall not be required over concrete or masonry walls designed in accordance with Chapters 19 and 21, respectively.
- Compliance with the requirements for a means of drainage, and the requirements of Sections 1404.2 and 1405.4, 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.
- 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.
- Exterior insulation and finish systems (EIFS) complying with Section 1408.4.1.
MINIMUM THICKNESS OF WEATHER COVERINGS
|Adhered masonry veneer||0.25|
|Anchored masonry veneer||2.625|
|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|
|Glass-fiber reinforced concrete panels||0.375|
|High-yield copperd||0.0162 nominal|
|Lead-coated copperd||0.0216 nominal|
|Lead-coated high-yield copper||0.0162 nominal|
|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|
|Stucco or exterior cement plaster|
|Three-coat work over:|
|Metal plaster base||0.875b|
|Cast-in-place or precast concrete||0.625b|
|Two-coat work over:|
|Cast-in-place or precast concrete||0.375b|
|Terra cotta (anchored)||1|
|Terra cotta (adhered)||0.25|
|Wood siding (without sheathing)a||0.5|
For SI: 1 inch = 25.4 mm, 1 ounce per square foot = 0.305 kg/m2.
- Wood siding of thicknesses less than 0.5 inch shall be placed over sheathing that conforms to Section 2304.6.
- Exclusive of texture.
- As measured at the bottom of decorative grooves.
- 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.
Class III vapor retarders shall be permitted where any one of the conditions in Table 1405.3.1 is met.
CLASS III VAPOR RETARDERS
|ZONE||CLASS III VAPOR RETARDERS PERMITTED FOR:a|
Vented cladding over OSB
Vented cladding over plywood
Vented cladding over gypsum
Insulated sheathing with R-value ≥ R2.5 over 2×4 wall
Insulated sheathing with R-value ≥ R3.75 over 2×6 wall
Vented cladding over OSB
Vented cladding over plywood
Vented cladding over gypsum
Insulated sheathing with R-value ≥ R5 over 2×4 wallInsulated sheathing with R-value ≥ R7.5 over 2×6 wall
Vented cladding over gypsum
Insulated sheathing with R-value ≥ R7.5 over 2×4 wallInsulated sheathing with R-value ≥ R11.25 over 2×6 wall
|7 and 8|
Insulated sheathing with R-value ≥ R10 over 2×4 wallInsulated sheathing with R-value ≥ R15 over 2×6 wall
For SI: 1 pound per cubic foot = 16.02 kg/m3.
- Spray foam with a minimum density of 2 pounds per cubic feet applied to the interior cavity side of OSB, plywood, fiberboard, insulating sheathing or gypsum is deemed to meet the insulating sheathing requirement where the spray foam R-value meets or exceeds the specified insulating sheathing R-value.
The vapor retarder class shall be based on the manufacturer’s certified testing or a tested assembly.
The following shall be deemed to meet the class specified:
Sheet polyethylene, nonperforated aluminumfoil
Kraft-faced fiberglass batts or paint with a
perm rating greater than 0.1 and less than orequal to 1.0
|Class III:||Latex or enamel paint|
For the purposes of this section, vented cladding shall include the following minimum clear airspaces.
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:
- The veneer shall not exceed 40 feet (12 190 mm) in height above grade. Where fire-retardant-treated wood is used, the height shall not exceed 60 feet (18 290 mm) in height above grade.
- The veneer is attached to or furred from a noncombustible backing that is fire-resistance rated as required by other provisions of this code.
- 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.
- 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 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.
- With stud backing, a 2-inch by 2-inch (51 mm 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.
In Occupancy Groups R-2 and R-3, 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 at a height not less than 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 through which a 4-inch (102 mm) diameter sphere cannot pass.
Exception: Openings that are provided with window guards that comply with ASTM F 2006 or F 2090.
Combustible exterior wall coverings shall be tested in accordance with NFPA 268.
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.
MINIMUM FIRE SEPARATION FOR COMBUSTIBLE VENEERS
For SI: 1 foot = 304.8 mm.
On buildings of Type I, II, III and IV construction, exterior wall coverings shall be permitted to be constructed of wood in accordance with Section 1405.5, or other equivalent combustible material, complying with the following limitations:
- Combustible exterior wall coverings shall not exceed 10 percent of an exterior wall surface area where the fire separation distance is 5 feet (1524 mm) or less.
- Combustible architectural trim shall be limited to 40 feet (12 192 mm) in height above grade.
- Combustible exterior wall coverings constructed of fire-retardant-treated wood complying with Section 2303.2 for exterior installation shall not be limited in wall surface area where the fire separation distance is 5 feet (1524 mm) or less and shall be permitted up to 60 feet (18 288 mm) in height above grade regardless of the fire separation distance.
Balconies and 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 buildings perimeter on each floor.
- On buildings of Type I and II construction, three stories or less above grade plane, fire-retardant-treated wood shall be permitted for balconies, porches, decks and exterior stairways not used as required exits.
- Untreated wood is permitted for pickets and rails or similar guardrail devices that are limited to 42 inches (1067 mm) in height.
- 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.
- Where sprinkler protection is extended to the balcony areas, the aggregate length of the balcony on each floor shall not be limited.
Where MCM systems are used on exterior walls required to have a fire-resistance rating in accordance with Section 705, evidence shall be submitted to the building official that the required fire-resistance rating is maintained.
Exception: MCM systems not containing foam plastic insulation, which are installed on the outer surface of a fire-resistance-rated exterior wall in a manner such that the attachments do not penetrate through the entire exterior wall assembly, shall not be required to comply with this section.
The thermal barrier specified for MCM in Section 1407.10.2 is not required where:
- 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 typical details used in the installation and shall be tested in the manner intended for use.
- The MCM is used as elements of balconies and similar projections, architectural trim or embellishments.