CWUIC · California Wildland-Urban Interface Code

Which standards govern roof-covering fire tests used by the CWUIC?

For homeowners: In WUI areas the CWUIC requires roofs to be shown **Class A** by standardized tests — ASTM E108 or UL 790 — as a full roof assembly (covering plus tested underlayment when required). Use only the listed underlayment and follow the manufacturer’s listing and installation instructions; some materials (certain metal, tile, brick, or heavy copper) are accepted as Class A equivalents by the exceptions in the code.

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Last reviewed: July 6, 2026

What the code requires — plain English

The California Wildland‑Urban Interface Code requires roofs to meet a Class A fire classification based on standardized roof‑covering fire tests. The required test standards are ASTM E108 or UL 790; where an applicable underlayment is part of the assembly it must be listed and labeled as tested with the roof assembly. See § 504.2, § 504.2.1.2, and § 504.11.6 for the controlling language.

The single most important rule: roofs (and certain accessory‑building roofs) must be shown Class A by testing to ASTM E108 or UL 790 — or be an listed, equivalent assembly or an identified exception — before they are acceptable in WUI/Fire Hazard Severity Zones.

Requirements in detail

Governing standards and the basic rule

Required test standards: ASTM E108 (Standard Test Methods for Fire Tests of Roof Coverings) OR UL 790 (Standard Test Methods for Fire Tests of Roof Coverings). § 504.2 requires the roof assembly to comply with Class A when tested in accordance with one of these standards.
Definition to keep in mind: a roof assembly is the system consisting of the roof covering and roof deck (and may include underlayment, thermal barrier, insulation, etc.). Bolded terms are defined in the code. See the Roof Assembly definition.

Underlayment and assemblies (voids / profiles)

If the roof covering installation creates a void/airspace under the covering, the installation must comply with the airspace or underlayment rules (see § 504.2.1.1 and § 504.2.1.2).
§ 504.2.1.2 requires that a listed and labeled roof underlayment that has been tested as part of the roof assembly in accordance with ASTM E108 or UL 790 for Class A be installed in accordance with the underlayment manufacturer’s instructions and listing. The section also mandates use of bird stops at eaves (where the profile fits) and that hip and ridge caps be mudded in to reduce ember intrusion.

Accessory structures

§ 504.11.6 explicitly states that roof assemblies and roof coverings of accessory buildings that are required to be constructed entirely of noncombustible or ignition‑resistant materials shall comply with § 504.2 and § 504.2.1. It also reiterates that roofs in Fire Hazard Severity Zones must comply with Class A testing to ASTM E108 or UL 790, and that roof assemblies be installed in accordance with their listing and the manufacturer’s instructions.

Key items that appear as exceptions (still code text)

Certain assemblies are treated as equivalent to Class A and do not require testing (examples in § 504.2):
- Roof coverings of brick, masonry, or exposed concrete roof deck.
- Ferrous or copper shingles / metal sheets and shingles, clay or concrete roof tile, or slate installed on noncombustible decks (or certain metal installed without a roof deck on noncombustible framing).
- Minimum 16 oz/sq ft (0.0416 kg/m²) copper sheets installed over combustible decks.
- Slate installed over ASTM D226, Type II underlayment over combustible decks.

Decision‑relevant table

Decision dimension	Required value / action	Code reference
Required fire classification for roofs in WUI / Fire Hazard Severity Zones	Class A (tested)	§ 504.2
Acceptable test standards for roof‑covering classification	ASTM E108 or UL 790	§ 504.2
Roof underlayment used under a tested assembly	Listed & labeled underlayment tested as part of the roof assembly (Class A); install per listing/manufacturer	§ 504.2.1.2
Installation items for profiles with airspace / voids	Bird stops at eaves (where profile fits); mud hip & ridge caps	§ 504.2.1.2 and § 504.2.1.1
Accessory building roofs required to match main rules	Roofs of accessory buildings required to be noncombustible/ignition‑resistant must comply with § 504.2 and § 504.2.1; in Fire Hazard Severity Zones Class A applies	§ 504.11.6
Not tested but considered Class A equivalents	Brick/masonry/exposed concrete; certain metal, tile, slate installations; 16 oz/sq ft (0.0416 kg/m²) copper over combustible decks	§ 504.2

Exceptions & special cases

Where the roof sheathing is fire‑retardant‑treated wood labeled for exterior use and complies with CBC Section 2303.2, the underlayment is not required to comply with Class A under § 504.2.1.2 (Exception). Be sure to verify the sheathing labeling and compliance with CBC §2303.2 when relying on this exception.
Certain construction types are exempt from testing and are treated as Class A equivalents (see the list in § 504.2). Those are not “tested” but are accepted by code as equivalent when the listed conditions are met (materials, deck type, or copper weight).
For accessory buildings required to be constructed of noncombustible or ignition‑resistant materials, the roof still must follow the listed test/listing and installation rules; in Fire Hazard Severity Zones the Class A test requirement is explicit. § 504.11.6 ties accessory roofs back to the main roof rules.

Common mistakes

Assuming any Class A shingle alone is sufficient — the code requires the roof assembly be Class A when tested; an underlayment that is not listed as tested with the assembly can invalidate the classification. Check the assembly listing and manufacturer’s instructions. § 504.2 and § 504.2.1.2.
Installing a product marked “Class A” in one test configuration but not following the exact underlayment or deck used in that test. The code requires installation in accordance with the listing/manufacturer instructions. § 504.2.1.2.
Overlooking accessory buildings: if your shed or outbuilding falls into the categories in § 504.11, its roof may still need to meet the same assembly/testing requirements. § 504.11.6.
Expecting surface treatments (paint, coatings, stains) to substitute for tested materials — surface treatments are explicitly not an approved method of protection per the code sections addressing surface treatment (see Chapter 5 references).

Worked example — concrete scenario with numbers

Scenario: You’re installing a new roof on a 200 ft² accessory building located 10 ft (≥ 3 ft and < 50 ft) from the primary dwelling. The local authority requires that accessory buildings > 120 ft² and separated by 3–50 ft be constructed of noncombustible or ignition‑resistant materials.

Steps and how the code applies:

Because the accessory building is > 120 ft² and within the 3–50 ft band, the structure must be constructed of noncombustible or ignition‑resistant materials (see § 504.11.3 / § 504.11.6). Its roof therefore must comply with § 504.2 and § 504.2.1.
You select an asphalt‑composition shingle that is part of a listed Class A roof assembly when tested with a specific self‑adhering underlayment. Under § 504.2.1.2, you must install the listed and labeled underlayment that was tested as part of that Class A assembly, following the manufacturer’s instructions and the listing. If the assembly listing shows Class A only when used with Underlayment X, you cannot substitute Underlayment Y unless the listing includes it.
If the roof profile creates an airspace under the covering (e.g., certain metal shingles or shaped tiles that lift the covering above the deck), follow § 504.2.1.1 / § 504.2.1.2 requirements: install required cap sheet or listed underlayment and use bird stops at eaves and mud hip & ridge caps to prevent ember intrusion.
If instead you proposed copper sheets of 16 oz/sq ft (0.0416 kg/m²) over the combustible deck, that specific copper weight is listed as an exception and would be considered equivalent to Class A (no test needed) per § 504.2 — but you must meet the material/installation criteria in that exception.

Related provisions

§ 504.2 — Roof assembly (Class A requirement; exceptions)
§ 504.2.1.2 — Roof underlayment (listed/labeled underlayment tested as part of assembly; bird stops; hip/ridge mudding)
§ 504.2.1.1 — Airspace under roof covering (cap sheet and other installation items)
§ 504.11.6 — Roof construction for accessory buildings (ties accessory roofs to § 504.2 / § 504.2.1; Class A in Fire Hazard Severity Zones)
§ 503.3 — Standards of quality / labeling / approved agency (product testing and labeling requirements that support § 504)

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:
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 § 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:
1. Roof assemblies with coverings of brick, masonry or an exposed concrete roof deck.
2. 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.
3. 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 § 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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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:
1. Roof assemblies with coverings of brick, masonry or an exposed concrete roof deck.
2. 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.
3. 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 § 1404.7.1 High relevance — show source text
602—2022: Specification for Masonry Structures

1404.7.1, 1705.4, 1705A.4, 1705.4.1, 1807.1.6.3, 2101.2.2, 2101A.1.3, 2103.1, 2103.2.1, 2103.3, 2103A.3.1, 2103.4, 2104.1, 2104.2, 2104A, 2105.1, 2105A.1, 2105.2, 2105A.2, 2105.3, 2105A.3, 2106.6, 2115.3, 2115.4

604—2023: Standard for the Installation of Architectural Cast Stone

2104.1

TPI Truss Plate Institute, 2670 Crain Highway, Suite 203, Waldorf, MD 20601

ANSI/TPI 1—2022: National Design Standard for Metal Plate Connected Wood Truss Construction

2303.4.6, 2306.1

UBC International Code Council, Inc., 500 New Jersey Avenue, NW 6th Floor, Washington, DC 20001

UBC Standard 15-2: Test Standard for Determining the Fire Retardancy of Roof-Covering Materials

1505.6

UBC Standard 15-3: Wood Shakes

1505.6

UBC Standard 15-4: Wood Shingles

1505.6

UL UL LLC, 333 Pfingsten Road, Northbrook, IL 60062

9—2009: Fire Tests of Window Assemblies—with Revisions through March 2020 Table 716.1(1), 716.1.1, 716.1.2.2.2, 716.2.1.3, 716.3.1.1, 716.3.1.2, 716.3.2.1.3, 716.3.4, 1013.5

10A—2009: Tin Clad Fire Doors—with Revisions through July 20, 2018

716.2.1

10B—2008: Fire Tests of Door Assemblies—with Revisions through May 2020 Table 716.1(1), 716.1.1, 716.1.2.2.1, 716.2.1.2, 716.2.2.2, 716.2.2.3.1, 716.2.5.1.1

2025 CALIFORNIA BUILDING CODE 35-41

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REFERENCED STANDARDS

10C—2016: Positive Pressure Fire Tests of Door Assemblies—with Revisions through May 2021 Table 716.1(1), 716.1.1, 716.1.2.2.1, 716.2.1.1, 716.2.2.1, 716.2.2.2, 716.2.2.3.1, 716.2.5.1.1, 1010.2.8.3

10D—2017: Fire Tests of Fire-Protective Curtain Assemblies

716.4
CWUIC § 19428-2959 High relevance — show source text
REFERENCED STANDARDS

ASTM ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959

B42—20: Specification for Seamless Copper Pipe, Standard Sizes

909.13.1

B43—20: Specification for Seamless Red Brass Pipe, Standard Sizes

909.13.1

B68/B68M—19: Standard Specification for Seamless Copper Tube, Bright Annealed (Metric)

909.13.1

B88—20: Standard Specification for Seamless Copper Water Tube

909.13.1

B251/B251M—2017: Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tube

909.13.1

B280—20: Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service

909.13.1

D56—21a: Test Method for Flash Point by Tag Closed Cup Tester

202

D86—20b: Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure

202

D92—2018: Test Method for Flash and Fire Points by Cleveland Open Cup Tester

202, 2401.2, 5001.1, 5104.1.1, 5104.1.2, 5701.2,

D93—20: Test Methods for Flash Point by Pensky-Martens Closed Up Tester

202

D323—20a: Test Method for Vapor Pressure of Petroleum Products (Reid Method)

202

D2859—2016(2021): Standard Test Method for Ignition Characteristics of Finished Textile Floor Covering Materials

804.3.3.1, 804.3.3.2

D3278—21: Test Methods for Flash Point of Liquids by Small Scale Closed-Cup Apparatus

202

D3498—03(2011): Standard Specification for Adhesives for Field-Gluing Plywood to Lumber Framing for Floor Systems

701.6, 914.3.1.2, 3303.5

E84—21a: Standard Test Method for Surface Burning Characteristics of Building Materials

202, 803.1, 803.1.2, 803.3, 803.5.2, 803.10, 803.12, 803.13, 804.1.1, 804.1.2, 804.2.4, 3311.1

E108— 2020a : Standard Test Methods for Fire Tests of Roof Coverings

1207.9.5

E648—19ae1: Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source

804.3.1, 804.3.2, 804.4

E681—09(2015): Standard Test Method for Concentration Limits of Flammability of Chemicals (Vapors and Gases)

202

E1354—22: Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter

304.3.2, 304.3.4, 318.1, 2310.5.3, 3304.1.3, 3311.1, 3603.4

E1529—16e1: Standard Test Method for Determining Effects of Large Hydrocarbon Pool Fires on Structural Members and Assemblies
CWUIC § 9.3 High relevance — show source text
R202, R302.9.3, R302.9.4, R302.10.1, R302.10.2, R302.15, R303.3, R303.5.9, R303.5.11, R507.2.2.2, R703.14.3

790— Edition 9—2022 : Standard Test Methods for Fire Tests of Roof Coverings—with Revisions through October 2018

R302.2.4, R902.1

907—2016: Fireplace Accessories

R1001.13

959—2010: Medium Heat Appliance Factory-Built Chimneys—with Revisions through August 2019

R1005.6

1040—1996: Fire Test of Insulated Wall Construction—with Revisions through April 2017

R303.6

1256—2002: Fire Test of Roof Deck Construction—with Revisions through August 2018

R906.1

1479—2015: Fire Tests of Penetration Firestops—with Revisions through May 2021

R302.4.1.2

1482—2011: Solid-Fuel Type Room Heaters—with Revisions through February 2020

R1002.2, R1002.5

1618—2015: Wall Protectors, Floor Protectors, and Hearth Extensions—with Revisions through January 2018

R1004.2

1703—2002: Flat-Plate Photovoltaic Modules and Panels—with Revisions through November 2019

R329.3.1, R902.4

1715—1997: Fire Test of Interior Finish Material—with revisions through April 2017

R303.6

1741—2010: Inverters, Converters, Controllers and Interconnection System Equipment with Distributed Energy Resources—with Revisions through June 2021

R329.3.1, R330.6

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REFERENCED STANDARDS

1777—2015: Chimney Liners—with Revisions through April 2019

R1003.11.1, R1003.18

1897—2015: Uplift Tests for Roof Covering Systems—with Revisions through September 2020

R905.4.4.1, R905.9.4, R905.10.5, R905.11.4, R905.12.4, R905.13.4, R905.14.4

2034—2017: Single and Multiple Station Carbon Monoxide Alarms—with Revisions through September 2018

R310.1.1, R311.1.1

2075—2013: Gas and Vapor Detectors and Sensors—with Revisions through August 2021

R310.7.4, R311.7.1, R311.7.4

2200—2020: Stationary Engine Generator Assemblies

R331.1

2703—2014: Mounting Systems, Mounting Devices, Clamping/Retention Devices and Ground Lugs for Use with Flat-Plate Photovoltaic Modules and Panels—with Revisions through March 2021

R902.4

3741—2020: Photovoltaic Hazard Control

R329.6, R329.6.3, R329.6.4

CWUIC § 1508.2 High relevance — show source text

[BF] 1508.2 Material standards. Above-deck thermal insulation board shall comply with the standards in Table 1508.2.

[BF] TABLE 1508.2—MATERIAL STANDARDS FOR ROOF INSULATION	Col2
MATERIAL	STANDARD
Cellular glass board	ASTM C552 or ASTM C1902
Composite boards	ASTM C1289, Type III, IV, V or VII
Expanded polystyrene	ASTM C578
Extruded polystyrene	ASTM C578
Fiber-reinforced gypsum board	ASTM C1278
Glass-faced gypsum board	ASTM C1177
High-density polyisocyanurate board	ASTM C1289, Type II, Class 4
Mineral fiber insulation board	ASTM C726
Perlite board	ASTM C728
Polyisocyanurate board	ASTM C1289, Type I or II
Wood fiberboard	ASTM C208, Type II

SECTION 1509—ROOF COATINGS

1509.1 General. The installation of a roof coating on a roof covering shall comply with the requirements of Section 1505 and this section.

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ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

1509.2 Material standards. Roof coating materials shall comply with the standards in Table 1509.2.

TABLE 1509.2—ROOF COATING MATERIAL STANDARDS	Col2
MATERIAL	STANDARD
Acrylic coating	ASTM D6083
Asphaltic emulsion coating	ASTM D1227
Asphalt coating	ASTM D2823
Asphalt roof coating	ASTM D4479
Aluminum-pigmented asphalt coating	ASTM D2824
Silicone coating	ASTM D6694
Moisture-cured polyurethane coating	ASTM D6947

SECTION 1510—RADIANT BARRIERS INSTALLED ABOVE DECK

[BF] 1510.1 General. A radiant barrier installed above a deck shall comply with Sections 1510.2 through 1510.4.

[BF] 1510.2 Fire testing. Radiant barriers shall be permitted for use above decks where the radiant barrier is covered with an approved roof covering and the system consisting of the radiant barrier and the roof covering complies with the requirements of either FM 4450 or UL 1256.

[BF] 1510.3 Installation. The low emittance surface of the radiant barrier shall face the continuous airspace between the radiant barrier and the roof covering.

[BF] 1510.4 Material standards. A radiant barrier installed above a deck shall comply with ASTM C1313/C1313M.

SECTION 1511—ROOFTOP STRUCTURES

[BG] 1511.1 General. The provisions of this section shall govern the construction of rooftop structures.

CWUIC § 1.1 High relevance — show source text
403—2017: Direct Design Handbook for Masonry Structures

R606.1, R606.1.1, R606.12.1, R606.12.3.1

404—2023: Standard for the Design of Architectural Cast Stone

R606.1

602—2022: Specification for Masonry Structures

R606.2.10, R606.2.13, R703.12

TPI Truss Plate Institute 2670 Crain Highway, Suite 203 Waldorf, MD 20601

ANSI/TPI 1—2022: National Design Standard for Metal Plate Connected Wood Truss Construction

R502.12.1, R802.10.2

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REFERENCED STANDARDS

UBC International Code Council, Inc. 500 New Jersey Avenue, NW 6th Floor Washington, DC 20001

UBC Standard 15-2: Test Standard for Determining the Fire Retardancy of Roof-covering Materials

R902

UBC Standard 15-3: Wood Shakes

R902

UBC Standard 15-4: Wood Shingles

R902

UL UL LLC 333 Pfingsten Road Northbrook, IL 60062

55A—2004: Materials for Built-Up Roof Coverings

R905.9.2

103—2010: Factory-built Chimneys for Residential Type and Building Heating Appliances—with Revisions through September 2021

R202, R1005.3

127—2011: Factory-Built Fireplaces—with Revisions through February 2020

R1001.11, R1004.1, R1004.4, R1004.5, R1005.4

217—2015: Smoke Alarms—with Revisions through April 2021

R310.1.1, R311.1.1

263—2011: Fire Test of Building Construction and Materials—with Revisions through August 2021 Table R302.1(2), R302.2, R302.2.1, R302.2.2, R302.4.1, R302.11.1, R606.2.2

268—2016: Smoke Detectors for Fire Alarm Systems—with Revisions through October 2019

R310.7.1, R310.7.4, R311.7.4

325—2017: Door, Drapery, Gate, Louver and Window Operators and Systems—with Revisions through February 2020

R317.4

580—2006: Test for Uplift Resistance of Roof Assemblies—with Revisions through March 2019

R905.4.4.1, R905.9.4, R905.10.5, R905.11.4, R905.12.4, R905.13.4, R905.14.4

641—2010: Type L Low-Temperature Venting Systems—with Revisions through April 2018

R202, R1003.11.5

723—2018: Standard for Test for Surface Burning Characteristics of Building Materials

CWUIC § 1.5 High relevance — show source text

2025 CWUIC—continued	Col2	Adopted Yes/No	IWUIC Section	CBC Section	CFC Section	Title 14, Division 1.5 Section	Title 19, Division 1 Section	Gov Code Section	PRC Section	HSC Section
Section	Title	Title	Title	Title	Title	Title	Title	Title	Title	Title
Chapter 5	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations
503.2.4.3.3	Plastic lumber materials	Y		703A.6
503.2.5	Surface treatment protection	Y		703A.5.3
503.3	Standards of quality	Y		703A.1
503.3.1	Qualification by testing	Y		703A.2
503.3.2	Approved agency	Y		703A.3
503.3.3	Labeling	Y		703A.4
503.3.4	Fire-retardant- treated wood shin- gles and shakes	Y		703A.5.2.2
504	Ignition-resistant construction	Y		704A
504.1	General	Y		705A.1
504.2	Roof assembly	Y		705A.2 1505.2
504.2.1	Roof covering voids	Y		705A.2
504.2.1.1	Airspace under roof covering	Y		705A.2.1
504.2.1.2	Roof underlayment	Y		705A.2.2
504.2.2	Roof valleys	Y		705A.3
504.3	Protection of enclosed eaves	Y		707A.6
504.3.1	Protection of open eaves	Y		707A.5
504.4	Gutters and downspouts	Y		705A.4
504.5	Exterior walls	Y		707A.4
504.5.1	Flashing	Y	504.5.1
504.5.2	Exterior wall covering	Y		707A.3 704A.4 #3
504.5.2.1	Extent of exterior wall covering	Y		707A.3.1
504.6	Underfloor enclosure	Y		707A.9
504.

CWUIC § 1509.2 Medium relevance — show source text

1509.2 Material standards. Roof coating materials shall comply with the standards in Table 1509.2.

TABLE 1509.2—ROOF COATING MATERIAL STANDARDS	Col2
MATERIAL	STANDARD
Acrylic coating	ASTM D6083
Asphaltic emulsion coating	ASTM D1227
Asphalt coating	ASTM D2823
Asphalt roof coating	ASTM D4479
Aluminum-pigmented asphalt coating	ASTM D2824
Silicone coating	ASTM D6694
Moisture-cured polyurethane coating	ASTM D6947

SECTION 1510—RADIANT BARRIERS INSTALLED ABOVE DECK

[BF] 1510.1 General. A radiant barrier installed above a deck shall comply with Sections 1510.2 through 1510.4.

[BF] 1510.3 Installation. The low emittance surface of the radiant barrier shall face the continuous airspace between the radiant barrier and the roof covering.

[BF] 1510.4 Material standards. A radiant barrier installed above a deck shall comply with ASTM C1313/C1313M.

SECTION 1511—ROOFTOP STRUCTURES

[BG] 1511.1 General. The provisions of this section shall govern the construction of rooftop structures.

1511.1.1 Area limitation. The aggregate area of penthouses and other enclosed rooftop structures shall not exceed one-third the area of the supporting roof deck. Such penthouses and other enclosed rooftop structures shall not be required to be included in determining the building height, number of stories or building area as regulated by Section 503.1. The area of such penthouses shall not be included in determining the fire area specified in Section 901.7.

[BG] 1511.2 Penthouses. Penthouses in compliance with Sections 1511.2.1 through 1511.2.4 shall be considered as a portion of the story directly below the roof deck on which such penthouses are located. Other penthouses shall be considered as an additional story of the building.

[BG] 1511.2.1 Height above roof deck. Penthouses constructed on buildings of other than Type I construction shall not exceed 18 feet (5486 mm) in height above the roof deck as measured to the average height of the roof of the penthouse. Penthouses located on the roof of buildings of Type I construction shall not be limited in height.

Exception: Where used to enclose tanks or elevators that travel to the roof level, penthouses shall be permitted to have a maximum height of 28 feet (8534 mm) above the roof deck.

[BG] 1511.2.2 Use limitations. Penthouses shall not be used for purposes other than the shelter of mechanical or electrical equipment, tanks, elevators and related machinery, stairways or vertical shaft openings in the roof assembly, including ancillary spaces used to access elevators and stairways.

CWUIC § 1505.1.1 Medium 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 § 12-7 Medium relevance — show source text
(d) Conditions of acceptance. The test shall be regarded as successful if the transmission of heat through the protection during the period of fire exposure for which classification is desired does not raise the average (arithmetical) temperature of the thermocouples at one of the sections above 100°F (38°C), or does not raise the temperature above 1200°F (649°C) at any one of the measured points. The fire-resistance classification so derived shall be applicable to the beam, girder or truss when used with any floor or roof construction which has an equal or greater thermal capacity for heat dissipation from the beam than the floor or roof with which it was tested.

18 2025 CALIFORNIA REFERENCED STANDARDS CODE

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FIRE-RESISTIVE STANDARDS

TESTS OF CEILING CONSTRUCTIONS

Sec. 12-7-113.

(a) Application. This test procedure is to be used for classification of ceilings that are not an integral part of a floor construction and where 36 inches (914 mm) or more space is provided above the top of the joists or beams supporting and protected by the ceiling. (b) Size of sample. The area exposed to fire shall be not less than 180 square feet (16.7 m [2] ), with neither dimension less than 12 feet (3657 mm), and the ceiling surface at its edges shall be in contact with the test furnace structure.

(c) Test construction and enclosure. The test ceiling construction shall include all structural members and details including hangers, if any, but not walkways. Above the ceiling during the test, there shall be provided a tight flat-topped enclosure, the underside of the covering material of which shall be 36 inches (914 mm) above the top of the joists or beams supporting and protected by the ceiling. The top of the enclosure shall be made of cement-asbestos board [1] / 4 inch (6 mm) in thickness under asbestos millboard 1 / 2 inch (13 mm) in thickness, and the side walls of 8-inch (203 mm) common brick, or it shall be of a construction having equivalent heat conductivity and heat capacity. Where use of the ceiling under a combustible construction is contemplated, at least five 15-inch (381 mm) square panels of 1-inch (25 mm) pine boards shall be attached to the underside of the top of the enclosure. The temperatures on the bottom surface of these panels shall be measured.

(d) Conditions of acceptance. The test shall be regarded as successful if the following conditions are met:
1. The ceiling shall have withstood the fire endurance test without the passage of flame or ignition of combustible members or materials forming part of the construction above the ceilings as evidenced by glow or flame.
2. Transmission of heat through the ceiling during the fire endurance test shall not have been such as to raise the average temperature above the test ceiling more than indicated in Items A, B and C. The limiting temperatures shall be the average of those taken at not less than five points, one of which shall be approximately at the center, and four at approximately the centers of the quarter sections. A. With combustible supports or other combustible material in contact with the ceiling, the temperature increase at the points of contact shall not exceed 250°F (121°C).
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.

2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 5-9

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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. Medium 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:
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 § 507.1 Medium 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.

2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE 5-9

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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 § 503.1 Medium relevance — show source text

1||||||| |502|RESERVED|N||||||||| |503|Ignition-resistant
construction and
material|Y||704A||||||| |503.1|General|Y||701A.3||||||| |503.2|Ignition-resistant
building material|Y||707A.3 #2||||||| |503.2.1|Noncombustible
material|Y||704A.4 #1||||||| |503.2.2|Fire-retardant-
treated wood|Y||704A.4 #2||||||| |503.2.3|Fire-retardant-
treated wood roof
coverings|Y||705A.1||||||| |503.2.4|Other ignition-
resistant building
material|Y||704A.3||||||| |503.2.4.1|Flame spread|Y||704A.3 #1||||||| |503.2.4.2|Flame front|Y||704A.3 #2||||||| |503.2.4.3|Weathering|Y||703A.5.1||||||| |503.2.4.3.1|Evaluation require-
ments for weathering|Y||703A.5.2
703A.5.2.1||||||| |503.2.4.3.2|Wood-plastic
composite materials|Y||703A.6|||||||

APPENDIX H-28 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE

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APPENDIX H—REFERENCED CALIFORNIA DOCUMENTS

2025 CWUIC—continued	Col2	Adopted Yes/No	IWUIC Section	CBC Section	CFC Section	Title 14, Division 1.5 Section	Title 19, Division 1 Section	Gov Code Section	PRC Section	HSC Section
Section	Title	Title	Title	Title	Title	Title	Title	Title	Title	Title
Chapter 5	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations	Special building construction regulations
503.2.4.3.3	Plastic lumber materials	Y		703A.6
503.2.5	Surface treatment protection	Y		703A.5.3
503.3	Standards of quality	Y		703A.1
503.3.1	Qualification by testing	Y		703A.2
503.3.2	Approved agency	Y		703A.3
503.3.3	Labeling	Y		703A.4
_503.3.

CWUIC § 504.7 Medium relevance — show source text
Ignition Source Control Appendix A, A104 Ignition-Resistant Building Material 202, 503 Ignition-Resistant Construction 504 Appendages 504.7 Detached accessory structures 504.11 Eaves 504.3

Exterior doors 504.9

Exterior walls 504.5

Gutters and downspouts 504.4 Protection of eaves 504.3 Roof covering 504.2 Underfloor protection 504.6 Vents 504.10

Windows 504.8 Ignition-Resistant Construction and Material 503 Inspection and Enforcement 109 Abatement 109.3.8 Authority to inspect 109.1.2 Citations 109.3.4

Enforcement 109.2 Placarding 109.3.5.3 Prosecution 109.3.6

Reinspections 109.1.3 Right of entry 104.4 Testing 109.1.4 Unsafe conditions 109.3.5

Key Box 403.1

Land Use Limitations Appendix A, A108 Legal Defense of the Code Official 104.8.1 Liability of the Code Official 104.8

Log Wall Construction 202 LP-Gas Installations 606

Maintenance 101.6 Maintenance of Defensible Space 604 Modified area 604.2 Responsibility 604.3 Trees 604.4 Mapping of Wildland-Urban Interface Area 302.2 Multilayered Glazed Panels 202

Noncombustible Roof Covering 202

Outbuilding 202

Peer Review 104.2.2.7, 202 Permits

Application 105.4 Approval 105.5 Expiration 105.8 Issuance 105.6 Preliminary inspection 105.4.1 Refusal to issue 105.6.1

Required 105.2 Retention 105.9

Revocation 105.10 Validity 105.7 Work exempt from permit 105.3 Placarding as Unsafe 109.3.5.3 Powers and Duties of the Code

Official 104.1

Practical Difficulties 104.2.3 Protection of Pumps and Water Storage Facilities Appendix A, A107

Rafter Tail 202 Referenced Standards 102.4, Chapter 7 Registered Design Professional 104.2.1.2, 104.2.2.6.2, 106.1, 202 Residential Unit 202 Retroactivity 101.4 Ridgelline 202 Road 202 Roof Covering 202 Roof Covering System 202 Roof Coverings, Replacement or Repair of 507

Roof Deck 202

Scope 101 Self-Defense Mechanism Appendix G Service Utilities 111

Slope 202 Spark Arrestors 605 Stop Work Order 113 Storage of Firewood and Combustible Materials 607 Strategic Ridgeline 202 Structure 202

Subdivision 202

CWUIC § 1.5 Medium relevance — show source text

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APPENDIX H—REFERENCED CALIFORNIA DOCUMENTS

2025 CWUIC—continued	Col2	Adopted Yes/No	IWUIC Section	CBC Section	CFC Section	Title 14, Division 1.5 Section	Title 19, Division 1 Section	Gov Code Section	PRC Section	HSC Section
Section	Title	Title	Title	Title	Title	Title	Title	Title	Title	Title
Chapter 2	Definitions	Definitions	Definitions	Definitions	Definitions	Definitions	Definitions	Definitions	Definitions	Definitions
	Multilayered glazed panels	Y
	Noncombustible roof covering	Y
	Outbuilding (T14)	Y				1299.02(c)
	Peer review	Y
	Rafter tail	Y		702A
	Registered design professional	Y
	Residential unit (T14)	Y				1270.01(w)
	Ridgeline (topography) (T14)	Y				1270.01(x)
	Road (T14)	Y				1270.01(y)
	Roof assembly	Y
	Roof covering	Y
	Roof covering system	Y
	Roof deck	Y
	Roof eave	Y		702A
	Roof eave soffit	Y		702A
	Slope	Y
	State Responsibility Area (SRA)	Y		702A	4902.1
	Strategic ridgeline (T14)	Y				1270.01(dd)
	Structure	Y	202			1270.01(ee)
	Subdivision	Y
	Tree crown	Y
	Undeveloped ridgeline (T14)	Y				1270.01(ii)
	Unenclosed acces- sory structure	Y
	Vertical curve (T14)	Y				1270.01(k)
	Wildfire	Y		702A	4902.1
	Wildfire exposure	Y		702A	4902.1
	Wildland	Y
	Wildland-urban inter- face area	Y		702A	4902.1
Chapter 3	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas	Wildland-urban interface areas
301	General	Y
301.1	Scope	Y								4201
301.

CWUIC § 601.3 Medium relevance — show source text
Dead-end Road 202 Defensible Space 403, 601.3 Vegetation Plan 603 Definitions 202 Designation of Wildland-Urban Interface Area 302.1

Director 202 Driveway 202 Dumping Appendix A, A106 Dwelling 202

Exterior Covering 202

INDEX

Fees 109 Findings of Fact Appendix E Fire Chief 202 Fire Danger Rating System Appendix D Fire Flow Calculation Area Application 404.5 Defined 202 Fire Hazard Severity Zones 1.1.2, 202, 302.1, 302.2, Appendix D, Appendix H Fire Protection Plans 602

Fire Weather 202

Fire-Resistance-Rated Construction 501.3 Fire-Resistive Vegetation Appendix F Fire-Retardant-Treated Lumber or

Wood 503.2, 504.5, 504.7, 504.11 Flame Spread Index 202 Flashing 504.2.1, 504.5.1 Fuel Break 202, 609 Fuel Models Appendix D Fuel Modification 202

Fuel Modification Distance 603.2

Fuel Mosaic 202 Fuel-Loading 202

General Requirements Appendix A Green Belt 202

Greenways 202

Hammerhead/T 202 Hazardous Land Use 202

Hazardous Materials 202 Heavy Timber Construction 202

Ignition Source Control Appendix A, A104 Ignition-Resistant Building Material 202, 503 Ignition-Resistant Construction 504 Appendages 504.7 Detached accessory structures 504.11 Eaves 504.3

Exterior doors 504.9

Exterior walls 504.5

Gutters and downspouts 504.4 Protection of eaves 504.3 Roof covering 504.2 Underfloor protection 504.6 Vents 504.10

Windows 504.8 Ignition-Resistant Construction and Material 503 Inspection and Enforcement 109 Abatement 109.3.8 Authority to inspect 109.1.2 Citations 109.3.4

Enforcement 109.2 Placarding 109.3.5.3 Prosecution 109.3.6

Reinspections 109.1.3 Right of entry 104.4 Testing 109.1.4 Unsafe conditions 109.3.5

Key Box 403.1

Land Use Limitations Appendix A, A108 Legal Defense of the Code Official 104.8.1 Liability of the Code Official 104.8

Log Wall Construction 202 LP-Gas Installations 606

Maintenance 101.6 Maintenance of Defensible Space 604 Modified area 604.2 Responsibility 604.3 Trees 604.4 Mapping of Wildland-Urban Interface Area 302.2 Multilayered Glazed Panels 202

Noncombustible Roof Covering 202

Outbuilding 202
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 § 1.11. Medium relevance — show source text
- The California Code of Regulations (CCR), Title 19, Division 1 provisions that are found in the California Wildland-Urban Interface Code are a reprint from the current CCR, Title 19, Division 1 text for the code user’s convenience only. The scope, applicability and appeals procedures of CCR, Title 19, Division I remain the same. The state agency does not adopt sections identified by the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
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.

2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE APPENDIX G-1

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

APPENDIX G-2 2025 CALIFORNIA WILDLAND-URBAN INTERFACE CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

G VOLUNTARY HOME-HARDENING RECOMMENDATIONS

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.

Frequently asked questions

What exactly does “tested as part of the roof assembly” mean?

It means the underlayment (or any component) must have been included in the test assembly that produced the Class A listing; the product’s listing must identify the assembly configuration and permit installation per that listing. § 504.2.1.2.

Can I rely on a manufacturer’s “Class A shingle” label if I change the underlayment?

No. A shingle’s Class A designation applies only in the tested assembly listed by the manufacturer. If the Class A listing specifies a particular underlayment or deck, you must install it per the listing and manufacturer instructions. § 504.2.1.2.

Are metal roofs always exempt from testing?

No. Specific metal installations are listed as exceptions when installed on noncombustible decks (or certain metal installed without a deck on noncombustible framing). Check the exception text in § 504.2 for the exact conditions.

If my roof sheathing is fire‑retardant‑treated wood, do I still need a Class A underlayment?

If the sheathing is labeled for exterior use and complies with CBC § 2303.2, the underlayment is not required to comply with Class A per the exception in § 504.2.1.2 — but verify the labeling and CBC compliance.

Do accessory building roofs in the WUI have extra requirements?

Yes. If an accessory building is required to be built of noncombustible or ignition‑resistant materials, its roof must comply with § 504.2 and § 504.2.1; roofs in Fire Hazard Severity Zones must meet Class A via ASTM E108 or UL 790. § 504.11.6.

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G VOLUNTARY HOME-HARDENING RECOMMENDATIONS

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