CWUIC · California Wildland-Urban Interface Code
What roof assembly classification is required in Fire Hazard Severity Zones?
Homes and buildings located in mapped Fire Hazard Severity Zones must have roof assemblies that meet **Class A** performance (tested to **ASTM E108** or **UL 790**), unless they fall under specific code exceptions (e.g., certain tile, metal, masonry coverings). Profiled roofs that create an airspace need a 72‑lb cap sheet or ≥1" mineral wool (plus bird stops and mudded hip/ridge caps), and fire‑retardant wood shakes require specific listings and weathering approvals. See **§ 504.2**, **§ 1505.2**, and **§ 1505.6** for the controlling rules and exceptions.
Last reviewed: July 6, 2026
What the code requires — 2-4 sentences
The California Wildland‑Urban Interface Code (CWUIC) requires that roof assemblies installed in Fire Hazard Severity Zones have a Class A fire classification. This is the direct requirement of § 504.2. The Class A requirement is to be demonstrated by testing in accordance with ASTM E108 or UL 790 (see § 504.2).
In Fire Hazard Severity Zones, the roof assembly must perform to a Class A fire test (ASTM E108 or UL 790) unless specifically listed exceptions apply.
Requirements in detail
Short plain-English summary of the rule
- If your building is in a mapped Fire Hazard Severity Zone, the roof assembly must meet Class A performance (ASTM E108 or UL 790). § 504.2 is the controlling CWUIC clause.
- The California Building Code defines what Class A means and lists specific coverings that are treated as Class A or allowed as exceptions; see § 1505.2.
- Special rules apply when the roof profile creates a void (airspace) under the covering — see § 504.2.1, § 504.2.1.1 and § 504.2.1.2 for cap sheet, underlayment and other measures.
Decision-relevant table
| Decision factor | Requirement / value | Code reference |
|---|---|---|
| Required roof classification in Fire Hazard Severity Zones | Class A roof assembly (tested ASTM E108 or UL 790) | § 504.2. |
| What “Class A” means (definition / acceptance) | Assemblies effective against severe fire-test exposure; must be listed/identified as Class A by an approved testing agency | § 1505.2. |
| Listed exceptions treated as equivalent to Class A | Brick, masonry or exposed concrete deck; ferrous/copper/metal shingles or sheets, clay or concrete tile or slate on noncombustible decks; 16 oz/sq ft copper over combustible decks; some slate installations | § 504.2 (exceptions) and § 1505.2 (exceptions list). |
| Roof coverings creating an airspace under profile | If airspace exists over a combustible deck, one of these is required: (a) 72‑lb cap sheet meeting ASTM D3909 over the deck; or (b) 1" mineral wool (or other noncombustible material) between roofing and wood framing; plus bird stops at eaves and mudded hip/ridge caps | § 504.2.1.1 (cap sheet, mineral wool, bird stops, mudded caps). |
| Alternative for underlayment (listed assemblies) | A listed and labeled roof underlayment that was tested as part of the Class A roof assembly per ASTM E108 or UL 790 may be used; installation per manufacturer/listing | § 504.2.1.2. |
| Exception to underlayment requirement | If roof sheathing is fire‑retardant‑treated wood labeled for exterior use and it complies with CBC § 2303.2, underlayment need not meet the Class A underlayment requirement | Exception to § 504.2.1.2 (references CBC § 2303.2). |
| Fire‑retardant‑treated wood shakes / shingles | Must comply with UBC Standards cited and be listed (ICC‑ES EG107); meet weathering requirements in Health and Safety Code § 13132.7(j); labeled bundles required | § 1505.6 (and related labeling / H&S requirements). |
How the CWUIC and CBC interact (short)
- CWUIC § 504.2 is the direct CWUIC mandate for Fire Hazard Severity Zones (Class A).
- The California Building Code (CBC) provides the definitions and test/listing practices for Class A and for treatment/listing of wood shakes/shingles (§ 1505.2 and § 1505.6). CWUIC requirements draw on those definitions.
Exceptions & special cases
- The CWUIC lists specific coverings that are considered equivalent to Class A and therefore exempt from testing: brick, masonry, exposed concrete decks; metal (ferrous/copper) shingles or sheets; clay or concrete tile; slate (when installed on noncombustible decks or when special copper weight thresholds are met). See § 504.2.
- If a roofing profile creates an airspace under the covering (e.g., some barrel tiles), you must either install a 72‑lb cap sheet (ASTM D3909) over the deck or provide ≥ 1" mineral wool board (or other noncombustible material) between roofing and wood framing; bird stops and mudded hip/ridge caps are also required. See § 504.2.1.1.
- A listed and labeled underlayment that was tested as part of a Class A assembly may be installed instead when the listing supports it. See § 504.2.1.2.
- If the roof sheathing is fire‑retardant‑treated wood labeled for exterior use and meets CBC § 2303.2, the underlayment Class A requirement may not apply (see exception in § 504.2.1.2).
- Fire‑retardant‑treated wood shakes and shingles are not automatically acceptable unless they meet the listing/testing and weathering requirements set out in § 1505.6 and related Health & Safety Code provisions.
Common mistakes
- Mistaking a Class C or B roof covering as compliant when the building is in a Fire Hazard Severity Zone — CWUIC mandates Class A via § 504.2.
- Assuming any metal roof is exempt—only specific metal coverings and installation conditions described in the code are treated as equivalent; verify the exact exception text in § 504.2 and § 1505.2.
- Forgetting to address airspace created by profiled tiles; an untreated void under the covering can defeat compliance unless the cap sheet or noncombustible filler is provided per § 504.2.1.1.
- Installing fire‑retardant‑treated shakes without verifying ICC‑ES listing and the State Fire Marshal / Health & Safety weathering approval required by § 1505.6 and related H&S code references.
- Relying on surface coatings or paints to meet ignition resistance — CWUIC explicitly disallows surface treatment as a substitute (see related CWUIC text on surface treatments).
Worked example — concrete scenario
Scenario: New single‑family home in a Very High Fire Hazard Severity Zone. The owner proposes a profiled clay tile roof over conventional wood decking.
- CWUIC requires a Class A roof assembly for Fire Hazard Severity Zones — § 504.2. The owner must provide a Class A assembly or meet an exception.
- Clay tile on a noncombustible deck is listed among the allowable exceptions equivalent to Class A (no testing required) under § 504.2 / § 1505.2. If the deck is noncombustible and installation matches the exception, the requirement is satisfied.
- If the tile is installed over a combustible wood deck and the tile profile creates an airspace, you must either:
- Install a 72‑lb cap sheet complying with ASTM D3909 over the deck, or
- Provide ≥ 1‑inch mineral wool board (or other approved noncombustible material) between the roofing and wood framing; and install bird stops at eaves and mudded hip/ridge caps. See § 504.2.1.1.
- Alternatively, provide a listed Class A roof assembly (manufacturer listing showing ASTM E108 / UL 790 test results) with documented installation instructions — permitted by § 504.2.1.2.
So, if the homeowner chooses clay tile over a combustible deck, compliance can be achieved by either meeting the exception conditions (noncombustible deck), providing the 72‑lb cap sheet or 1" mineral wool plus bird stops/mudded caps, or installing a listed Class A assembly per the standards.
Related provisions (CWUIC / CBC)
- § 504.2 — Roof assembly: Class A requirement and listed exceptions.
- § 504.2.1, § 504.2.1.1, § 504.2.1.2 — Requirements for voids under roof covering, cap sheet, listed underlayment, and related exceptions.
- § 1505.2 — Definition and acceptance of Class A roof assemblies; enumerates similar exceptions.
- § 1505.6 — Requirements for fire‑retardant‑treated wood shingles and shakes (listing, ICC‑ES EG107, weathering).
- § 1505.1.1 — Cross‑reference: roofing in Fire Hazard Severity Zones must also comply with other CBC/WUI provisions (see CBC).
Code references
Grounded in the retrieved California Wildland-Urban Interface Code — click a citation to read the verbatim passage:
CWUIC § 4.882 High 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:
Class A roof assemblies include those with coverings of brick, masonry and exposed concrete roof deck.
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.
Class A roof assemblies include minimum 16 ounces per square foot (4.882 kg/m [2] ) copper sheets installed over combustible roof decks.
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 § 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:
Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.
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.
Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m [2] ) copper sheets installed over combustible decks.
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 § 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.|2025 CALIFORNIA BUILDING CODE 15-5
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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:
- Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.
- 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.
- Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m [2] ) copper sheets installed over combustible decks.
CWUIC § 504.1 High relevance — show source text
� SECTION 504—IGNITION-RESISTANT CONSTRUCTION
504.1 General. Ignition-resistant construction shall be in accordance with Sections 504.2 through 504.11.6 .
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504.2 Roof assembly. Roofs shall have a roof assembly that complies with a Class A fire classification when tested in accordance with ASTM E108 or UL 790.
Exceptions: The following assemblies are exempt from testing and shall be considered as equivalent to the Class A fire classification:
- Roof assemblies with coverings of brick, masonry or an exposed concrete roof deck.
- Roof assemblies with 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.
- Roof assemblies with minimum 16 oz/sq ft (0.0416 kg/m [2] ) copper sheets installed over combustible roof decks. 4. Roof assemblies of slate roof covering installed over ASTM D226, Type II underlayment over combustible decks.
504.2.1 Roof covering voids. Where there is a void under the roof covering it shall comply with Section 504.2.1.1 or 504.2.1.2.
504.2.1.1 Airspace under roof covering. Where the roof covering is installed over a combustible deck and the roofing profile creates an airspace under the roof covering, the installation shall comply with the following: 1. A 72 lb. (32.7 kg) cap sheet complying with ASTM D3909 Standard Specification for “Asphalt Rolled Roofing (Glass Felt) Surfaced with Mineral Granules,” shall be installed over the roof deck.
Exception: Cap sheet is not required where not less than 1 inch of mineral wool board or other noncombustible material is located between the roofing material and wood framing or deck. 2. Bird stops shall be used at the eaves where the profile fits, to prevent the entry of debris at the eave. 3. Hip and ridge caps shall be mudded in to prevent intrusion of fire or embers.
504.2.1.2 Roof underlayment. A listed and labeled roof underlayment that has been tested as part of the roof assembly in accor- dance with ASTM E108 or UL 790 for Class A fire classification shall be installed in accordance with the underlayment manufacturer’s installation instructions and listing. Bird stops shall be used at the eaves when the profile fits, to prevent the entry of debris at the eave. Hip and ridge caps shall be mudded in to prevent intrusion of fire or embers.
Exception: Where the roof sheathing is fire-retardant-treated wood labeled for exterior use and complies with Section 2303.2 of the California Building Code, the underlayment shall not be required to comply with a Class A fire classification.
CWUIC § 503.2.5 High relevance — show source text
503.2.5 Surface treatment protection. Use of paints, coatings, stains or other surface treatments are not an approved method of protection as required in this chapter.
503.3 Standards of quality. Building material, systems, assemblies and methods of construction shall be tested in accordance with the standards specified in Chapter 5.
503.3.1 Qualification by testing. Material and material assemblies tested in accordance with the requirements of Section 503 shall be accepted for use when the results and conditions of those tests are met. Product evaluation testing of material and material assemblies shall be approved or listed by the State Fire Marshal or identified in a current report issued by an approved agency.
503.3.2 Approved agency. Product evaluation testing shall be performed by an approved agency in accordance with Section 1703 of the California Building Code. The scope of accreditation for the approved agency shall include building product compliance with this code.
503.3.3 Labeling. Material and material assemblies tested in accordance with the referenced standards shall bear an identification label showing the fire test results. That identification label shall be issued by a testing and/or inspecting agency approved by the State Fire Marshal.
1. Identification mark of the approved testing and/or inspecting agency.
2. Contact and identification information of the manufacturer.
3. Model number or identification of the product or material. 4. Pretest weathering specified in this chapter. 5. Compliance standard as described under Chapter 7.
503.3.4 Fire-retardant-treated wood shingles and shakes. Fire-retardant-treated wood shingles and shakes shall be approved and listed by the State Fire Marshal in accordance with Section 208(c), Title 19 California Code of Regulations.
� SECTION 504—IGNITION-RESISTANT CONSTRUCTION
504.1 General. Ignition-resistant construction shall be in accordance with Sections 504.2 through 504.11.6 .
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SPECIAL BUILDING CONSTRUCTION REGULATIONS
504.2 Roof assembly. Roofs shall have a roof assembly that complies with a Class A fire classification when tested in accordance with ASTM E108 or UL 790.
Exceptions: The following assemblies are exempt from testing and shall be considered as equivalent to the Class A fire classification:
- Roof assemblies with coverings of brick, masonry or an exposed concrete roof deck.
- Roof assemblies with 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.
- Roof assemblies with minimum 16 oz/sq ft (0.0416 kg/m [2] ) copper sheets installed over combustible roof decks. 4. Roof assemblies of slate roof covering installed over ASTM D226, Type II underlayment over combustible decks.
504.2.1 Roof covering voids. Where there is a void under the roof covering it shall comply with Section 504.2.1.1 or 504.2.1.2.
CWUIC § 705.5 High relevance — show source text
b|2a, b, c|1b, c|0c|1b, c|0|3a|2a|2a|HT|1b, c|0| |Bearing walls||||||||||||| |Exteriore, f|3|2|1|0|2|2|3|2|2|2|1|0| |Interior|3a|2a|1|0|1|0|3|2|2|1/HTg|1|0| |Nonbearing walls and partitions
Exterior|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5|See Table 705.5| |Nonbearing walls and partitions
Interiord|0|0|0|0|0|0|0|0|0|See
Section
2304.11.2|0|0| |Floor construction and associated
secondary structural members (see
Section 202)|2|2|1|0|1|0|2|2|2|HT|1|0| |Roof construction and associated
secondary structural members
(see Section 202)|11/2
b|1b, c|1b, c|0c|1b, c|0|11/2|1|1|HT|1b, c|0| |For SI: 1 foot = 304.8 mm.
a. Roof supports: Fire-resistance ratings of primary structural frame and bearing walls are permitted to be reduced by 1 hour where supporting a roof only.
b._ 1._ Except in Group_A, E,_ F-1, H,I, L,M, R-1, R-2, R-2.1 and S-1 occupancies,high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire
_Marshal, _fire protection of structural members in roof construction shall not be required, including protection of primary structural frame members, roof framing and
decking where every part of the roof construction is 20 feet or more above any floor or mezzanine immediately below. Fire-retardant-treated wood members shall be
allowed to be used for such unprotected members.
2. For Group A, E, I, L, R-1, R-2 and R-2.1 occupancies, high-rise buildings, and other applications listed in Section 1.11 regulated by the Office of the State Fire Marshal, fire protec-
tion of members other than the primary structural frame shall not be required, including protection of roof framing and decking where every part of the roof construction is 20
feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
3. One-story portions of Group A and E assembly occupancies the roof-framing system of Type II A or Type III A construction may be of unprotected construction when such roof-
framing system is open to the assembly area and does not contain concealed spaces.
c. In all occupancies, heavy timber complying with Section 2304.11 shall be allowed for roof construction, including primary structural frame members, where a 1-hour or less
fire-resistance rating is required.
d.CWUIC § 1.0 High relevance — show source text
Interpolation shall be permitted for wind speed, mean roof height and parapet height. Extrapolation is not permitted.
c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
surface and not less than the height of the aggregate.
e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
basic wind speed in Section 1609.
f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).|SECTION 1505—FIRE CLASSIFICATION
[BF] 1505.1 General. Fire classification of roof assemblies shall be in accordance with Section 1505. The minimum fire classification of roof assemblies installed on buildings shall comply with Table 1505.1 based on type of construction of the building. Class A, B and C roof assemblies and roof coverings required to be listed by this section shall be tested in accordance with ASTM E108 or UL 790. In addition, fire-retardant-treated woodroof coverings shall be tested in accordance with ASTM D2898; fire-retardant-treated shingles and shakes shall comply with Section 1505.6.
Exception: Skylights and sloped glazing that comply with Chapter 24 or Section 2610.
[BF] TABLE 1505.1—MINIMUM ROOF ASSEMBLY CLASSIFICATION FOR TYPES OF CONSTRUCTIONa, b Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 IA IB IIA IIB IIIA IIIB IV VA VB B B B Cc B Cc B B Cc 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.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.CWUIC § 302.2 High relevance — show source text
Each fire hazard severity zone shall_ embrace relatively homogeneous lands, and the classification shall be based on fuel loading, slope, fire weather and other relevant factors including areas where winds have been identified by the Office of the State Fire Marshal as a major cause of wildfire spread and other areas designated by the enforcing agency to be at a significant risk from wildfires.
302.2 Review of wildland-urban interface areas. The code official shall reevaluate and recommend modification to the wildlandurban interface areas in accordance with Section 302.1 on a 5-year basis or more frequently as deemed necessary by the legislative body. The State Fire Marshal shall periodically review the areas in the state identified as fire hazard severity zones and, as necessary, shall make recommendations relative to fire hazard severity zones. This review shall coincide with the review of state responsibility area lands every five years and, when possible, fall within the time frames for the county’s general plan update.
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CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE
CHAPTER 4 – WILDLAND-URBAN INTERFACE AREA 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-
CGSFM Col5 HCD Col7 Col8 DSA Col10 OSHPD Col12 Col13 Col14 Col15 Col16 BSCC DPH AGR DWR CEC CA SL SLC Adopting Agency BSC BSC-
CGT-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 402 † 402.1.1 X 402.1.2 X 402.1.2.1 X 402.2.1 X 402.2.2 X 402. CWUIC § 302.1 High relevance — show source text
SECTION 302—WILDLAND-URBAN INTERFACE AREA DESIGNATIONS
302.1 Mapping . The State Fire Marshal shall classify lands into Fire Hazard Severity Zones in accordance with California Public Resources Code, Sections 4201 through 4204 for State Responsibility Areas and in accordance with Government Code, Sections 51175 through 51189 for Local Responsibility Areas. The State Fire Marshal shall designate areas in the state as fire hazard severity zones and assign each zone based on the severity of fire hazard that is expected to prevail in those areas. Each fire hazard severity zone shall embrace relatively homogeneous lands, and the classification shall be based on fuel loading, slope, fire weather and other relevant factors including areas where winds have been identified by the Office of the State Fire Marshal as a major cause of wildfire spread and other areas designated by the enforcing agency to be at a significant risk from wildfires.
302.2 Review of wildland-urban interface areas. The code official shall reevaluate and recommend modification to the wildlandurban interface areas in accordance with Section 302.1 on a 5-year basis or more frequently as deemed necessary by the legislative body. The State Fire Marshal shall periodically review the areas in the state identified as fire hazard severity zones and, as necessary, shall make recommendations relative to fire hazard severity zones. This review shall coincide with the review of state responsibility area lands every five years and, when possible, fall within the time frames for the county’s general plan update.
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CALIFORNIA WILDLAND-URBAN INTERFACE CODE – MATRIX ADOPTION TABLE
CHAPTER 4 – WILDLAND-URBAN INTERFACE AREA 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 § 1.5 High relevance — show source text
The California Code of Regulations (CCR), Title 14, Division 1.5 provisions that are found in the California Wildland-Urban Interface Code are not listed in the Matrix Adoption Tables as they are not within the State Fire Marshal’s authority to adopt. These provisions are a reprint from the current CCR, Title 14, Division 1.5 text for the code user’s convenience only and are identified in the body of the code by square brackets containing references to applicable Title 14 sections.
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3 WILDLAND-URBAN INTERFACE AREAS
User notes:
About this chapter: Chapter 3 provides for the fundamental aspect of applying the code—the legal declaration and establishment of wildlandurban interface areas within the adopting jurisdiction, mapping of the area, periodic review and updates.
SECTION 301—GENERAL
301.1 Scope. The provisions of this chapter provide methodology to establish and record wildland-urban interface areas in accor- dance with California Public Resources Code (PRC) and California Government Code (GC).
301.2 Purpose . The purpose of this chapter is to classify lands in the state in accordance with the level of fire hazard present for the purpose of identifying measures that will retard the rate of spread and reduce the potential intensity of uncontrolled fires that threaten to destroy resources, life or property, and to require that those measures be taken.
SECTION 302—WILDLAND-URBAN INTERFACE AREA DESIGNATIONS
302.1 Mapping . The State Fire Marshal shall classify lands into Fire Hazard Severity Zones in accordance with California Public Resources Code, Sections 4201 through 4204 for State Responsibility Areas and in accordance with Government Code, Sections 51175 through 51189 for Local Responsibility Areas. The State Fire Marshal shall designate areas in the state as fire hazard severity zones and assign each zone based on the severity of fire hazard that is expected to prevail in those areas. Each fire hazard severity zone shall embrace relatively homogeneous lands, and the classification shall be based on fuel loading, slope, fire weather and other relevant factors including areas where winds have been identified by the Office of the State Fire Marshal as a major cause of wildfire spread and other areas designated by the enforcing agency to be at a significant risk from wildfires.
302.2 Review of wildland-urban interface areas. The code official shall reevaluate and recommend modification to the wildlandurban interface areas in accordance with Section 302.1 on a 5-year basis or more frequently as deemed necessary by the legislative body. The State Fire Marshal shall periodically review the areas in the state identified as fire hazard severity zones and, as necessary, shall make recommendations relative to fire hazard severity zones. This review shall coincide with the review of state responsibility area lands every five years and, when possible, fall within the time frames for the county’s general plan update.
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CWUIC § 1.2 High relevance — show source text
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).
Health and Safety Code Section 13132.7 (j) No wood roof covering materials shall be sold or applied in this state unless both of the following conditions are met: (1) The materials have been approved and listed by the State Fire Marshal as complying with the requirements of this section. (2) The materials have passed at least five years of the 10-year natural weathering test. The 10-year natural weathering test required by this subdivision shall be conducted in accordance with Standard 15-2 of the 1994 edition of the Uniform Building Code at a testing facility recognized by the State Fire Marshal.
R902.3 Building-integrated photovoltaic (BIPV) systems. Building-integrated photovoltaic (BIPV) systems installed as the roof covering shall be tested, listed and labeled for fire classification in accordance with UL 7103 [SFM] Section R902.1 through R902.1.2. Class A, B or C BIPV products shall be installed where the edge of the roof is less than 3 feet (914 mm) from a lot line.
R902.4 Rooftop-mounted photovoltaic (PV) panel systems. Rooftop-mounted photovoltaic (PV) panel systems installed on or above the roof covering shall be tested, listed and identified with a fire classification in accordance with UL 2703. Listed systems shall be installed in accordance with the manufacturer’s installation instructions and their listing. Class A, B or C photovoltaic panel systems
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ROOF ASSEMBLIES
and modules shall be installed in jurisdictions designated by law as requiring their use or where the edge of the roof is less than 3 feet (914 mm) from a lot line.
SECTION R903—WEATHER PROTECTION
CWUIC § 1.0 High relevance — show source text
Extrapolation is not permitted.
c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
surface and not less than the height of the aggregate.
e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
basic wind speed in Section 1609.
f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
a. Parapet height is measured vertically from the top surface of the coping down to the surface of the roof covering in the field of the roof adjacent to the parapet and outbound
of any cant strip.
b. Interpolation shall be permitted for wind speed, mean roof height and parapet height. Extrapolation is not permitted.
c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
surface and not less than the height of the aggregate.
e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
basic wind speed in Section 1609.
f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).|SECTION 1505—FIRE CLASSIFICATION
[BF] 1505.1 General. Fire classification of roof assemblies shall be in accordance with Section 1505. The minimum fire classification of roof assemblies installed on buildings shall comply with Table 1505.1 based on type of construction of the building. Class A, B and C roof assemblies and roof coverings required to be listed by this section shall be tested in accordance with ASTM E108 or UL 790. In addition, fire-retardant-treated woodroof coverings shall be tested in accordance with ASTM D2898; fire-retardant-treated shingles and shakes shall comply with Section 1505.6.
Exception: Skylights and sloped glazing that comply with Chapter 24 or Section 2610.
Frequently asked questions
Can I use a Class B roof covering in a Fire Hazard Severity Zone?
No. In Fire Hazard Severity Zones the CWUIC requires a Class A roof assembly per § 504.2. Only the specific exceptions listed in the code are treated as equivalent.
Are clay or concrete tiles automatically acceptable?
Clay or concrete tile on a noncombustible deck is listed among exceptions treated equivalent to Class A in § 504.2 and § 1505.2. If installed over a combustible deck or the installation creates an airspace, the CWUIC’s airspace requirements apply (see § 504.2.1.1).
What if my roof profile creates a void under the tiles?
You must comply with § 504.2.1.1: either install a 72‑lb cap sheet (ASTM D3909) over the deck or provide ≥ 1" mineral wool board (or other approved noncombustible material) between roofing and wood framing, plus bird stops and mudded hip/ridge caps.
Can I use fire‑retardant‑treated wood shakes?
Only if they are listed/approved and meet the testing and weathering requirements in § 1505.6 (ICC‑ES EG107, H&S § 13132.7(j), labeling). Also remember the CWUIC Class A requirement still applies in Fire Hazard Severity Zones.
Does a manufacturer’s label/listing matter?
Yes. Class A assemblies and approved fire‑retardant coverings must be listed and labeled by an approved testing agency per § 1505.2, and CWUIC references require labeling and testing documentation.
More in California Wildland-Urban Interface Code
- Administration and Definitions
- Board of Appeals, Administration & Enforcement (permits, code official duties, appeals process)
- Wildland‑Urban Interface Area Designation & Mapping
- Fire Service Access & Water Supply (fire apparatus roads, driveways, hydrants, draft sites, standby power)
- Wildland‑Urban Interface Area Requirements (access, water, premises identification, key boxes)
- Referenced Standards & Test Methods
- Special Building Construction Regulations (ignition‑resistant construction, roof/vent/assembly requirements)
- Appendices and Model Ordinances (vegetation plans, severity‑zone adoption, home‑hardening guidance)
- Fire Protection Requirements (fire protection plans, systems, safety element provisions)
- Referenced California Documents & Matrix (CCR/Title 14 & 19 cross‑references, statutory references)
- Vegetation Management & Defensible Space (vegetation plans, maintenance, fire‑smart characteristics)
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