Section R337.7

EXTERIOR COVERING

R337.7.1 Scope. The provisions of this section shall gov- ern the materials and construction methods used to resist building ignition and/or safeguard against the intrusion of flames resulting from small ember and short-term direct flame contact exposure.

R337.7.2 General. The following exterior covering mate- rials and/or assemblies shall comply with this section:

1. Exterior wall covering material.

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2. Exterior wall assembly.

3. Exterior exposed underside of roof eave overhangs.

4. Exterior exposed underside of roof eave soffits.

5. Exposed underside of exterior porch ceilings.

6. Exterior exposed underside of floor projections.

7. Exterior underfloor areas.

Exceptions:

1. Exterior wall architectural trim, embellishments, fascias and gutters.

2. Roof or wall top cornice projections and similar assemblies.

3. Roof assembly projections over gable end walls.

4. Solid wood rafter tails and solid wood blocking installed between rafters having minimum dimen- sion 2 inch (50.8 mm) nominal.

5. Deck walking surfaces shall comply with Section R337.9 only.

R337.7.3 Exterior walls. The exterior wall covering or wall assembly shall comply with one of the following requirements:

1. Noncombustible material.

2. Ignition-resistant material.

3. Sawn lumber or glue-laminated wood with the smallest minimum nominal dimension of 4 inches (102 mm). Sawn or glue-laminated planks splined, tongue-and-grove, or set close together and well spiked.

4. Log wall construction assembly.

5. Wall assemblies that have been tested in accordance with the test procedures for a 10-minute direct flame contact exposure test set forth in ASTM E2707 with the conditions of acceptance shown in Section R337.7.3.1.

6. Wall assemblies that meet the performance criteria in accordance with the test procedures for a 10-min- ute direct flame contact exposure test set forth in SFM Standard 12-7A-1.

Exception: Any of the following shall be deemed to meet the assembly performance criteria and intent of this section:

1. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind the exterior covering or cladding on the exterior side of the framing.

2. The exterior portion of a 1-hour fire resistive exterior wall assembly designed for exterior fire exposure including assemblies using the gypsum panel and sheathing products listed in the Gyp- sum Association Fire Resistance Design Manual.

R337.7.3.1 Conditions of acceptance when tested in accordance with ASTM E2707. The ASTM E2707 test shall be conducted on a minimum of three test speci-

BUILDING PLANNING

mens and the conditions of acceptance in 1 and 2 below shall be met. If any one of the three tests does not meet the conditions of acceptance, three additional tests shall be run. All of the additional tests shall meet the conditions of acceptance.

1. Absence of flame penetration through the wall assembly at any time.

2. Absence of evidence of glowing combustion on the interior surface of the assembly at the end of the 70-minute test.

R337.7.3.2 Extent of exterior wall covering. Exterior wall coverings shall extend from the top of the founda- tion to the roof, and terminate at 2 inch (50.8 mm) nomi- nal solid wood blocking between rafters at all roof overhangs, or in the case of enclosed eaves, terminate at the enclosure.

R337.7.4 Open roof eaves. The exposed roof deck on the underside of unenclosed roof eaves shall consist of one of the following:

1. Noncombustible material. 2. Ignition-resistant material. 3. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind an exterior covering on the under- side exterior of the roof deck. 4. The exterior portion of a 1-hour fire resistive exte- rior wall assembly applied to the underside of the roof deck designed for exterior fire exposure includ- ing assemblies using the gypsum panel and sheath- ing products listed in the Gypsum Association Fire Resistance Design Manual.

Exceptions: The following materials do not require protection:

1. Solid wood rafter tails on the exposed underside of open roof eaves having a minimum nominal dimension of 2 inch (50.8 mm).

2. Solid wood blocking installed between rafter tails on the exposed underside of open roof eaves hav- ing a minimum nominal dimension of 2 inch (50.8 mm).

3. Gable end overhangs and roof assembly projec- tions beyond an exterior wall other than at the lower end of the rafter tails.

4. Fascia and other architectural trim boards.

R337.7.5 Enclosed roof eaves and roof eave soffits. The exposed underside of enclosed roof eaves having either a boxed-in roof eave soffit with a horizontal underside, or sloping rafter tails with an exterior covering applied to the underside of the rafter tails, shall be protected by one of the following:

1. Noncombustible material.

2. Ignition-resistant material.

3. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind an exterior covering on the under- side of the rafter tails or soffit.

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

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BUILDING PLANNING

4. The exterior portion of a 1-hour fire resistive exterior wall assembly applied to the underside of the rafter tails or soffit including assemblies using the gypsum panel and sheathing products listed in the Gypsum Association Fire Resistance Design Manual.

5. Boxed-in roof eave soffit assemblies with a horizon- tal underside that meet the performance criteria in Section R337.7.10 when tested in accordance with the test procedures set forth in ASTM E2957.

6. Boxed-in roof eave soffit assemblies with a horizon- tal underside that meet the performance criteria in accordance with the test procedures set forth in SFM Standard 12-7A-3.

Exceptions: The following materials do not require protection:

1. Gable end overhangs and roof assembly projec- tions beyond an exterior wall other than at the lower end of the rafter tails.

2. Fascia and other architectural trim boards.

R337.7.6 Exterior porch ceilings. The exposed underside of exterior porch ceilings shall be protected by one of the following:

1. Noncombustible material.

2. Ignition-resistant material.

3. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind the exterior covering on the under- side of the ceiling.

4. The exterior portion of a 1-hour fire resistive exterior wall assembly applied to the underside of the ceiling assembly including assemblies using the gypsum panel and sheathing products listed in the Gypsum Association Fire Resistance Design Manual.

5. Porch ceiling assemblies with a horizontal under- side that meet the performance criteria in Section R337.7.10 when tested in accordance with the test procedures set forth in ASTM E2957.

6. Porch ceiling assemblies with a horizontal under- side that meet the performance criteria in accor- dance with the test procedures set forth in SFM Standard 12-7A-3.

Exception: Architectural trim boards.

R337.7.7 Floor projections. The exposed underside of a cantilevered floor projection where a floor assembly extends over an exterior wall shall be protected by one of the following:

1. Noncombustible material.

2. Ignition-resistant material.

3. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind an exterior covering on the under- side of the floor projection.

4. The exterior portion of a 1-hour fire resistive exte- rior wall assembly applied to the underside of the floor projection including assemblies using the gyp-

sum panel and sheathing products listed in the Gyp- sum Association Fire Resistance Design Manual.

5. The underside of a floor projection assembly that meet the performance criteria in Section R337.7.10 when tested in accordance with the test procedures set forth in ASTM E2957.

6. The underside of a floor projection assembly that meet the performance criteria in accordance with the test procedures set forth in SFM Standard 12- 7A-3.

Exception: Architectural trim boards.

R337.7.8 Underfloor protection. The underfloor area of elevated or overhanging buildings shall be enclosed to grade in accordance with the requirements of this chapter or the underside of the exposed underfloor shall consist of one of the following:

1. Noncombustible material.

2. Ignition-resistant material.

3. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind an exterior covering on the under- side of the floor projection.

4. The exterior portion of a 1-hour fire resistive exte- rior wall assembly applied to the underside of the floor including assemblies using the gypsum panel and sheathing products listed in the Gypsum Associ- ation Fire Resistance Design Manual.

5. The underside of a floor assembly that meets the performance criteria in Section R337.7.10 when tested in accordance with the test procedures set forth in either of the following:

5.1. SFM Standard 12-7A-3; or

5.2. ASTM E2957.

6. The underside of a floor assembly that meets the performance criteria in accordance with the test procedures set forth in SFM Standard 12-7A-3.

Exception: Structural columns and beams do not require protection when they are constructed with sawn lumber or glue laminated wood with the smallest mini- mum nominal dimension of 4 inches (102 mm). Sawn or glue-laminated planks splined, tongue-and-grove, or set close together and well spiked.

R337.7.9 Underside of appendages. When required by the enforcing agency the underside of overhanging append- ages shall be enclosed to grade in accordance with the requirements of this chapter or the underside of the exposed underfloor shall consist of one of the following:

1. Noncombustible material.

2. Ignition-resistant material.

3. One layer of ⁵ /8-inch Type X gypsum sheathing applied behind an exterior covering on the under- side of the floor projection.

4. The exterior portion of a 1-hour fire resistive exte- rior wall assembly applied to the underside of the floor including assemblies using the gypsum panel

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Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

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and sheathing products listed in the Gypsum Associ- ation Fire Resistance Design Manual.

5. The underside of a floor assembly that meets the performance criteria in accordance with the test procedures set forth in either of the following:

5.1. SFM Standard 12-7A-3; or

5.2. ASTM E2957;

Exception: Structural columns and beams do not require protection when they are constructed with sawn lumber or glue-laminated wood with the smallest mini- mum nominal dimension of 4 inches (102 mm). Sawn or glue-laminated planks splined, tongue-and-grove, or set close together and well spiked.

R337.7.10 Conditions of acceptance when tested in accordance with ASTM E2957. The test shall be con- ducted on a minimum of three test specimens and the conditions of acceptance in 1 through 3 below shall be met. If any one of the three tests does not meet the condi- tions of acceptance, three additional tests shall be run. All of the additional tests shall meet the conditions of acceptance.

1. Absence of flame penetration of the eaves or hori- zontal projection assembly at any time.

2. Absence of structural failure of the eaves or hori- zontal projection subassembly at any time.

3. Absence of sustained combustion of any kind at the conclusion of the 40-minute test.