Roof Assembly, Coverings and Replacement Rules

Grounded in the retrieved California Wildland-Urban Interface Code — click a citation to read the verbatim passage:

• CWUIC § 507.1 High relevance — show source text

  SECTION 505— RESERVED

  SECTION 506— RESERVED

  SECTION 507—REPLACEMENT OR REPAIR OF ROOF COVERINGS

  507.1 General. The roof covering on buildings or structures in existence prior to the adoption of this code that are replaced or have 50 percent or more replaced in a 12-month period shall be replaced with a roof covering required for new construction in accordance with Sections 504.2 and 504.2.1. All portions of a roof covering applied during an addition, alteration or repair to an existing structure shall meet at least a Class A fire classification.

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  CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE

  CHAPTER 6 – FIRE PROTECTION REQUIREMENTS

  (Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

  Adopting Agency	BSC	BSC- CG	SFM	Col5	HCD	Col7	Col8	DSA	Col10	OSHPD	Col12	Col13	Col14	Col15	Col16	BSCC	DPH	AGR	DWR	CEC	CA	SL	SLC
  Adopting Agency	BSC	BSC- CG	T-24	T-19*	1	2	1/AC	AC	SS	1	1R	2	3	4	5	5	5	5	5	5	5	5	5
  Adopt Entire Chapter
  Adopt Entire Chapter as amended (amended sections listed below)			X
  Adopt only those sections that are listed below
  [California Code of Regulations, Title 19, Division 1]
  Chapter / Section
  601.1			X
  601.2			X
  601.3			X
  602.1 –602.3.2			X
  603.1 –603.4.2.1			X
  604.1			X
  604.2 –604.4			X
  606.1			X
  606.3			X
  607.

• CWUIC § 1505.1.1 High relevance — show source text

  ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

  1505.1.1 Roofing requirements within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI). Roofing require- ments for structures located within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI) shall also comply with Section 705A.

  1505.1.2 Roof coverings within all other areas other than Fire Hazard Severity Zones or a Wildland-Urban Interface (WUI). The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be a fire-retardant roof covering that is at least Class C fire classification.

  [BF] 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 identified 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.

  Exceptions:

  1. Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.

  2. Class A roof assemblies also include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile or slate installed on noncombustible decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.

  3. Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m [2] ) copper sheets installed over combustible decks.

  4. Class A roof assemblies include slate installed over ASTM D226, Type II or ASTM D4869, Type IV underlayment over combustible decks.

  [BF] 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.

  [BF] 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.

  [BF] 1505.5 Nonclassified roofing. Nonclassified roofing is approved material that is not listed as a Class A, B or C roof covering assembly or roof covering.

  [BF] 1505.6 Fire-retardant-treated wood shingles and shakes. Fire-retardant-treated wood shakes and shingles are wood shakes and shingles complying with UBC Standard 15-3 or 15-4 which are impregnated by the full-cell vacuum-pressure process with fire-retar- dant chemicals, and which have been qualified by UBC Standard 15-2 or ASTM E108 or UL 790 for use on Class A, B or C roofs.

  Fire-retardant-treated wood shakes and shingles shall comply with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7(j). Each bundle shall bear labels from an ICC accredited quality control agency identifying their roof-covering classification and indicating their compliance with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7(j).

• CWUIC § 2.1 High relevance — show source text

  This appendix is for informational purposes and is not intended for adoption.

  User notes:

  About this appendix: Appendix G is an information appendix that provides discussion of some elements of the proposed self-defense mechanisms and their role in enhancing the protection of exposed structures in the wildland-urban interface. The items provided in this appendix provide owners with suggestions for increasing the survivability of their structure. These items are not mandatory but can be considered by owners to increase the safety of structures.

  SECTION G101—GENERAL

  G101.1 Identification of the problem. The California Wildland-Urban Interface Code establishes a set of minimum standards to reduce the loss of property from wildfire. The purpose of these standards is to prevent wildfire spreading from vegetation to a building. Many homes were built in the wildland-urban interface areas prior to the implementation of provisions found in this code. As a result, many homes are lacking in their ability to survive an approaching wildfire. Many of the features discussed in this appendix are designed as low- cost features to retrofit existing homes. Additionally, recommendations are provided beyond the minimum code requirements for those homeowners who desire to increase the survivability of their home. This appendix chapter provides a discussion of some possible self- defense features to enhance survivability and harden the structure against an approaching wildfire.

  G101.2 Structural survivability. The home-hardening features listed in Section G101.2.1 were developed as a best practices guide to assist homeowners in increasing the ignition resistance of their homes from wildfires. Some of these items are based on upgrading to more stringent building materials when that building component is due for replacement as part of its normal maintenance or lifespan, such as the roof covering.

  G101.2.1 Home-hardening features. If homes are not already provided with the suggested protection, the following items should be considered in hardening a home against wildfire. 1. When it is time to replace your roof, replace it with roof assembly classified as Class A when tested in accordance with ASTM E108 or UL 790.

  2. Block any spaces at the eaves between your roof covering and sheathing with noncombustible materials (bird stops). 3. Install a noncombustible rain gutter and downspouts. Install rain gutter covers to prevent the accumulation of leaves and debris in the gutters. 4. Cover your chimney and stovepipe outlets with a noncombustible, corrosion-resistant metal mesh screen (spark arrestor), with [3] / 8 -inch (9.5 mm) to [1] / 2 -inch (12.7 mm) openings. 5. Install ember- and flame-resistant vents. Choose products that have been approved and labeled as OSFM Wildland-Urban Interface (WUI) Products. A temporary solution is to cover the vent openings with a noncombustible and corrosion-resistant mesh with [1] / 16 -inch (1.6 mm) to [1] / 8 -inch (3.2 mm) openings. 6. Caulk and plug gaps greater than [1] / 8 inch (3.2 mm) around exposed rafters and blocking to prevent ember intrusion into the attic or other enclosed spaces. 7. _Inspect exterior siding for dry rot, gaps, cracks and warping.

• CWUIC § 504.3 High relevance — show source text

  504.3 Protection of enclosed eaves. The exposed underside of enclosed roof eaves and soffits shall be protected on the exposed underside by one or more of the following:

  1. Noncombustible materials.

  2. Ignition-resistant building materials. 3. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

  4. 2-inch (51 mm) nominal dimension lumber . 5. 1-inch (25 mm) nominal fire-retardant-treated lumber or [3] / 4 -inch (19.1 mm) nominal fire-retardant-treated plywood, identified for exterior use and complying with Section 2303.2 of the California Building Code . 6. Boxed-in roof eave soffit assemblies with an underside that meets the performance criteria in Section 504.7.2 when tested in accordance with the test procedures set forth in ASTM E2957. 7. Boxed-in roof eave soffit assemblies with an underside that meets the performance criteria in accordance with the test proce- dures set forth in SFM Standard 12-7A-3.

  Facias are required and shall be ignition-resistant building materials , fire-retardant-treated wood labeled for exterior use and complying with Section 2303.2 of the California Building Code, materials approved for not less than 1-hour fire-resistance-rated construction or 2-inch (51 mm) nominal dimension lumber.

  504.3.1 Protection of open eaves. The exposed roof deck on the underside of unenclosed roof eaves shall consist of one or more of the following:

  1. Noncombustible material.

  2. Ignition-resistant building material. 3. Fire-retardant-treated wood labeled for exterior use and complying with Section 2303.2 of the California Building Code. 4. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

  5. 2-inch (51 mm) nominal dimension lumber. 6. One layer of [5] / 8 -inch (16 mm) Type X gypsum sheathing applied behind an exterior covering on the underside of the roof deck.

  7. The exterior portion of a 1-hour fire-resistance-rated exterior assembly, as tested in accordance with ASTM E119 or UL 263, applied to the underside of the roof deck designed for exterior fire exposure, including assemblies using the gypsum panel and sheathing products listed in the Gypsum Association Fire Resistance Design Manual.

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  SPECIAL BUILDING CONSTRUCTION REGULATIONS

  Facias, if provided, shall be of fire-retardant-treated wood labeled for exterior use and complying with Section 2303.2 of the Cali- fornia Building Code, ignition-resistant building materials, materials approved for not less than 1-hour fire-resistance-rated construction or 2-inch (51 mm) nominal dimension lumber.

• CWUIC § 1512.2 High relevance — show source text

  1512.2 Roof replacement. Roof replacement shall include the removal of all existing layers of roof assembly materials down to the roof deck.

  Exceptions:

  1. Where the existing roof assembly includes an ice barrier membrane that is adhered to the roof deck and the existing sheathing is not water-soaked or deteriorated to the point that it is not adequate as a base for additional roofing, the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane in accordance with Section 1507 where permitted by the roof covering manufacturer and new ice barrier underlayment manufacturer.
  2. Where the existing roof includes a self-adhered underlayment and the existing sheathing is not water-soaked or deteriorated to the point that it is not adequate as a base for additional roofing, the existing self-adhered underlayment shall be permitted to remain in place and covered with an underlayment complying with Tables 1507.1.1(1), 1507.1.1(2) and 1507.1.1(3).
  3. Where the existing roof includes one layer of self-adhered underlayment and the existing layer cannot be removed without damaging the roof deck, a second layer of self-adhered underlayment is permitted to be installed over the existing self-adhered underlayment provided that the following conditions are met: 3.1. It is permitted by the roof covering manufacturer and self-adhered underlayment manufacturer. 3.2. The existing sheathing is not water-soaked or deteriorated to the point that it is not adequate as a base for additional roofing.

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  ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

  3.3. The second layer of self-adhered underlayment is installed such that buildup of material at walls, valleys, roof edges, end laps and side laps does not exceed two layers.

  1512.3 Roof recover. The installation of a new roof covering over an existing roof covering shall be permitted where any of the following conditions occur:

  1. Where the new roof covering is installed in accordance with the roof covering manufacturer’s approved instructions.
  2. Complete and separate roofing systems, such as standing-seam metal roof panel 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.
  3. 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 1512.3.1.
  4. The application of a new protective roof coating over an existing protective roof coating, metal roof panel, built-up roof, spray polyurethane foam roofing system, metal roof shingles, mineral-surfaced roll roofing, modified bitumen roofing or thermoset and thermoplastic single-ply roofing shall be permitted without tear off of existing roof coverings.

  Exception: A roof recover shall not be permitted where any of the following conditions occur:

  1. 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. The existing roof covering is slate, clay, cement or asbestos-cement tile.
  3. The existing roof has two or more applications of any type of roof covering.
• CWUIC § 504.11.3 High relevance — show source text

  504.11.3 Accessory buildings greater than 120 square feet, located 3 feet or more but less than 50 feet. Accessory buildings that are greater than 120 square feet (11.15 m2) in size and separated from an applicable building on the same lot by a distance of 3 feet (914 mm) or more but less than 50 feet (15 240 mm) shall be constructed of noncombustible materials or of ignition-resistant building materials as described in Section 503.2.4.

  504.11.4 Accessory buildings 120 square feet or less, located 3 feet or more but less than 50 feet. Where required by the code offi- cial, accessory buildings 120 square feet (11.15 m2) or less and separated from an applicable building on the same lot by a distance of 3 feet (914 mm) or more but less than 50 feet (15 240 mm) shall be constructed of noncombustible materials or of ignition-resistant building materials as described in Section 503.2.4.

  504.11.5 Miscellaneous structures located 3 feet or more but less than 50 feet. Where required by the code official, miscellaneous structures that require a permit and are separated from an applicable building on the same lot by a distance of 3 feet (914 mm) or more but less than 50 feet (15 240 mm) shall be constructed of noncombustible materials or of ignition-resistant building materials as described in Section 503.2.4.

  504.11.6 Roof construction. Roof assemblies and roof coverings of accessory buildings required to be constructed entirely of noncombustible materials or of ignition-resistant building materials shall comply with Sections 504.2 and 504.2.1. Roofs shall have a roofing assembly installed in accordance with its listing and the manufacturer’s installation instructions. Roof assemblies in Fire Hazard Severity Zones shall comply with a Class A fire classification when tested in accordance with ASTM E108 or UL 790.

  SECTION 505— RESERVED

  SECTION 506— RESERVED

  SECTION 507—REPLACEMENT OR REPAIR OF ROOF COVERINGS

  507.1 General. The roof covering on buildings or structures in existence prior to the adoption of this code that are replaced or have 50 percent or more replaced in a 12-month period shall be replaced with a roof covering required for new construction in accordance with Sections 504.2 and 504.2.1. All portions of a roof covering applied during an addition, alteration or repair to an existing structure shall meet at least a Class A fire classification.

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  CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE

  CHAPTER 6 – FIRE PROTECTION REQUIREMENTS

  (Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)

• CWUIC § 1505.7. High relevance — show source text

  Buildings that are not more than two stories above grade plane 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 constructed in accordance with Section 1505.7.|For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
  a. Unless otherwise required in accordance with the_California 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 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 above grade plane 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 constructed in accordance with Section 1505.7.|

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  ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

  1505.1.1 Roofing requirements within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI). Roofing require- ments for structures located within Fire Hazard Severity Zones or in the Wildland-Urban Interface (WUI) shall also comply with Section 705A.

  1505.1.2 Roof coverings within all other areas other than Fire Hazard Severity Zones or a Wildland-Urban Interface (WUI). The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be a fire-retardant roof covering that is at least Class C fire classification.

  [BF] 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 identified 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.

  Exceptions:

  1. Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.
  2. Class A roof assemblies also include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile or slate installed on noncombustible decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.
  3. Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m [2] ) copper sheets installed over combustible decks.
• CWUIC § 9-19 High relevance — show source text

  R908.2 Structural and construction loads. The 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 roof covering system.

  R908.3 Roof replacement. Roof replacement shall include the removal of existing layers of roof coverings down to the roof deck.

  Exceptions:

  1. Where the existing roof assembly includes an ice barrier membrane that is adhered to the roof deck and the existing sheathing is not water soaked or deteriorated to the point that it is not adequate as a base for additional roofing, the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane in accordance with Section R905 where permitted by the roof covering manufacturer and new ice barrier underlayment manufacturer.
  2. Where the existing roof includes a self-adhered underlayment and the existing sheathing is not water soaked or deteriorated to the point that it is not adequate as a base for additional roofing, the existing self-adhered underlayment shall be

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  ROOF ASSEMBLIES

  permitted to remain in place and covered with an underlayment complying with Table R905.1.1(1), Table R905.1.1(2) and Table R905.1.1(3). 3. Where the existing roof includes one layer of self-adhered underlayment and the existing layer cannot be removed without damaging the roof deck, a second layer of self-adhered underlayment is permitted to be installed over the existing self-adhered underlayment provided that the following conditions are met: 3.1. It is permitted by the roof covering manufacturer and new self-adhered underlayment manufacturer. 3.2. The existing sheathing is not water soaked or deteriorated to the point that it is not adequate as a base for additional roofing. 3.3. The second layer of self-adhered underlayment is installed such that buildup of material at walls, valleys, roof edges, end laps, and side laps does not exceed two layers.

  R908.4 Roof recover. The installation of a new roof covering over an existing roof covering shall be permitted where any of the following conditions occur:

  1. Where the new roof covering is installed in accordance with the roof covering manufacturer’s approved instructions.
  2. 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 do not rely on existing roofs and roof coverings for support, shall not require the removal of existing roof coverings.
  3. Metal panel, metal shingle and concrete and clay tile roof coverings shall be permitted to be installed over existing wood shake roofs where applied in accordance with Section R908.4.1.
  4. The application of a new protective roof coating over an existing protective roof coating, metal roof panel, metal roof shingle, mineral surfaced roll roofing, built-up roof, modified bitumen roofing, thermoset and thermoplastic single-ply roofing and spray polyurethane foam roofing system shall be permitted without tear-off of existing roof coverings.
• CWUIC § 504.5.1 Medium relevance — show source text

  Such material shall extend from the top of the foundation to the underside of the roof sheathing.

  504.5.1 Flashing. A minimum of 6 inches (152 mm) of metal flashing or noncombustible material applied vertically on the exterior of the wall shall be installed at the ground, decking and roof intersections.

  504.5.2 Exterior wall coverings. Exterior wall coverings shall comply with one or more of the following requirements:

  1. Noncombustible material.

  2. Ignition-resistant building material labeled for exterior use. 3. Fire-retardant-treated wood labeled for exterior use and complying with the requirements of Section 2303.2 of the Califor- nia Building Code. 4. Fire-retardant-treated wood shingles and shakes which have been qualified in accordance with Section 1505.6 of the Cali- fornia Building Code for use as “Class B” roof covering shall be an acceptable alternative wall covering material where installed over solid sheathing.

  Exception: Exterior wall coverings which are a component of an approved wall assembly complying with Section 504.5.

  504.5.2.1 Extent of exterior wall covering. Where provided, exterior wall coverings shall extend from the top of the foundation to the roof, and terminate at 2-inch (50.8 mm) nominal solid wood blocking between rafters at all roof overhangs, or in the case of enclosed eaves, terminate at the enclosure.

  504.6 Underfloor enclosure. Buildings or structures shall have underfloor areas enclosed to the ground with exterior walls in accordance with Section 504.5.

  Exception: Complete enclosure shall not be required where the underside of exposed floors and exposed structural columns, beams and supporting walls are protected as required for exterior 1-hour fire-resistance-rated construction or heavy timber construction or fire-retardant-treated wood. The fire-retardant-treated wood shall be labeled for exterior use and meet the requirements of Section 2303.2 of the California Building Code .

  504.7 Projections . Unenclosed accessory structures attached to buildings with habitable spaces and projections, other than decks, shall be heavy timber construction or constructed of one of the following:

  1. Noncombustible materials.

  2. Fire-retardant-treated wood identified for exterior use and meeting the requirements of Section 2303.2 of the California Building Code .

  3. Ignition-resistant building materials in accordance with Section 503.2. 4. Materials approved for not less than 1-hour fire-resistance-rated construction on the exterior side, as tested in accordance with ASTM E119 or UL 263.

  5. One layer of [5] / 8 -inch (15.9 mm) Type X gypsum sheathing applied behind the exterior covering on the underside of the ceiling. 6. The exterior portion of a 1-hour fire-resistance-rated exterior assembly, as tested in accordance with ASTM E119 or UL 263, 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. 7. The underside of a floor projection assembly that meets the performance criteria in Section 504.7.2 when tested in accordance with the test procedures set forth in ASTM E2957.

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• CWUIC § 3-3 Medium relevance — show source text

  301 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

  302 Wildland-Urban Interface Area Designations . . . . . .3-3

  CHAPTER 4 WILDLAND-URBAN INTERFACE AREA

  REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . 4-3

  401 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

  402 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

  403 Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

  404 Water Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

  CHAPTER 5 SPECIAL BUILDING CONSTRUCTION

  REGULATIONS . . . . . . . . . . . . . . . . . . . . . . . . 5-3

  501 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3

  502 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3

  503 Ignition-Resistant Construction and Material. . . . . .5-3

  504 Ignition-Resistant Construction. . . . . . . . . . . . . . . . . .5-4

  505 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9

  506 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9

  507 Replacement or Repair of Roof Coverings. . . . . . . . .5-9

  CHAPTER 6 FIRE PROTECTION REQUIREMENTS. . . . . . .6-3

  601 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

  602 Fire Protection Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

  603 Vegetation Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

  604 Maintenance of Defensible Space . . . . . . . . . . . . . . . 6-5

• CWUIC § 4.882 Medium relevance — show source text

  Chapter 9 also provides requirements for roof drainage, flashing, above-deck thermal insulation, rooftop-mounted photovoltaic systems and recovering or replacing an existing roof covering.

  SECTION R901—GENERAL

  R901.1 Scope. The provisions of this chapter shall govern the design, materials, construction and quality of roof assemblies.

  SECTION R902—FIRE CLASSIFICATION

  R902.1 Roof assemblies. Roof decks shall be covered with materials as set forth in Section R904 or with roof coverings as set forth in Section R905. A minimum Class A, B or C roofing shall be installed in areas designated by this section or where the edge of the roof deck is less than 3 feet (914 mm) from a lot line. Where Class A, B or C roof assemblies are required, they shall be tested in accordance with ASTM E108 or UL 790. Where required, the roof assembly shall be listed and identified as to class by an approved testing agency.

  Exceptions:

  1. Class A roof assemblies include those with coverings of brick, masonry and exposed concrete roof deck.

  2. Class A roof assemblies include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile, or slate installed on noncombustible roof decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.

  3. Class A roof assemblies include minimum 16 ounces per square foot (4.882 kg/m [2] ) copper sheets installed over combustible roof decks.

  4. Class A roof assemblies include slate installed over underlayment over ASTM D226, Type II underlayment over combustible decks.

  R902.1.1 Roofing requirements within Fire Hazard Severity Zones or in Wildland-Urban Interface (WUI) area. Roofing require- ments for structures located within Fire Hazard Severity Zones or in a Wildland-Urban Interface (WUI) area shall also comply with Part 7, California Wildland-Urban Interface Code.

  R902.1.2 Roof coverings in all other areas other than Fire Hazard Severity Zones or a Wildland-Urban Interface (WUI) area. The entire roof covering of every existing structure where more than 50 percent of the total roof area is replaced within any one-year period, the entire roof covering of every new structure, and any roof covering applied in the alteration, repair or replacement of the roof of every existing structure, shall be a fire-retardant roof covering that is at least Class C fire classification.

  R902.2 Fire-retardant-treated shingles and shakes. Fire-retardant-treated wood shakes and shingles are wood shakes and shin- gles complying with UBC Standard 15-3 or 15-4 which are impregnated by the full-cell vacuum-pressure process with fire-retardant chemicals, and which have been qualified by UBC Standard 15-2 or ASTM E108 or UL 790 for use on Class A, B or C roofs. Fire-retardant- treated wood shakes and shingles shall comply with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7 (j). Each bundle shall bear labels from an ICBO accredited quality control agency identifying their roof-covering classification and indicating their compliance with ICC-ES EG107 and with the weathering requirements contained in Health and Safety Code Section 13132.7 (j).

• CWUIC § 1511.10.1 Medium relevance — show source text

  1511.10.1 Design. [BSC, DSA-SS, DSA-SS/CC, HCD 1 & HCD 2, OSHPD 1, 1R, 2, 4 & 5] Supports and attachments of photovoltaic panels to the roof structure, the panels, modules and components shall be designed in accordance with this code. 1. Seismic design shall be in accordance with ASCE 7 Section 13.6.12. 2. Wind design pressures shall be determined from ASCE 7 Section 29.4.3 or 29.4.4 using effective wind area in accordance with ASCE 7 Section 26.2.

  Construction documents for the supports and attachments shall be submitted to the enforcement agency for approval.

  SECTION 1512—REROOFING

  1512.1 General. Materials and methods of application used for recovering or replacing an existing roof covering shall comply with the requirements of Chapter 15.

  Exceptions:

  1. Roof replacement or roof recover of existing low-slope roof coverings shall not be required to meet the minimum design slope requirement of [1] / 4 unit vertical in 12 units horizontal (2-percent slope) in Section 1507 for roofs that provide positive roof drainage and meet the requirements of Sections 1608.3 and 1611.2.
  2. Recovering or replacing an existing roof covering shall not be required to meet the requirement for secondary (emergency overflow) drains or scuppers in Section 1502.2 for roofs that provide for positive roof drainage and meet the requirements of Sections 1608.3 and 1611.2. For the purposes of this exception, existing secondary drainage or scupper systems required in accordance with this code shall not be removed unless they are replaced by secondary drains or scuppers designed and installed in accordance with Section 1502.2.

  1512.2 Roof replacement. Roof replacement shall include the removal of all existing layers of roof assembly materials down to the roof deck.

  Exceptions:

  1. Where the existing roof assembly includes an ice barrier membrane that is adhered to the roof deck and the existing sheathing is not water-soaked or deteriorated to the point that it is not adequate as a base for additional roofing, the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane in accordance with Section 1507 where permitted by the roof covering manufacturer and new ice barrier underlayment manufacturer.
  2. Where the existing roof includes a self-adhered underlayment and the existing sheathing is not water-soaked or deteriorated to the point that it is not adequate as a base for additional roofing, the existing self-adhered underlayment shall be permitted to remain in place and covered with an underlayment complying with Tables 1507.1.1(1), 1507.1.1(2) and 1507.1.1(3).
  3. Where the existing roof includes one layer of self-adhered underlayment and the existing layer cannot be removed without damaging the roof deck, a second layer of self-adhered underlayment is permitted to be installed over the existing self-adhered underlayment provided that the following conditions are met: 3.1. It is permitted by the roof covering manufacturer and self-adhered underlayment manufacturer. 3.2. The existing sheathing is not water-soaked or deteriorated to the point that it is not adequate as a base for additional roofing.

  15-24 2025 CALIFORNIA BUILDING CODE