Roofs shall be covered with materials as set forth in Sections R904 and 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 is less than 3 feet (914 mm) from a lot line. Class A, B and C roofing required by this section to be listed shall be tested in accordance with UL 790 or ASTM E108.
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 decks.
- Class A roof assemblies include minimum 16 ounces per square foot copper sheets installed over combustible decks.
- Class A roof assemblies include slate installed over underlayment over combustible decks.
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 A.
Exception: The requirements shall not apply in any jurisdiction that adopts the model ordinance approved by the State Fire Marshal pursuant to Section 51189 of the Government Code or an ordinance that substantially conforms to the model ordinance and transmits a copy to the State Fire Marshal.
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 B.
Exception: Areas designated as moderate fire hazard severity zones.
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.
Roofing requirements for structures located in a wildland-urban interface fire area shall also comply with Section R337.5.