Roofing and Eaves
Roof and edge components (such as gutters) are arguably the most important part of a home in terms of making it safer from wildfires. While a home may only be subjected to the flaming front of the wildfire for a few minutes, the roof (and the rest of the house) could be subjected to airborne glowing or burning embers for a few hours as the wildfire approaches and burns through an area.
See a video demonstration of some of the things to keep in mind about the roof and roof edge.
|R1||Is the roof covering something other than Class A fire rated?||Class A roof covering:|
Roof coverings can obtain a Class A rating based on the covering alone (called a stand-alone Class A) or based on the covering and underlying materials that provide additional fire protection (called an assembly-rated Class A). Common stand alone Class A roof coverings include: asphalt composition ('3-tab') shingles, clay tiles, concrete tiles, and slate.
Common assembly rated Class A coverings include: aluminum (metal) roofs; fire-retardant treated wood shakes (with Class B fire rating, approved by the California Office of the State Fire Marshal as a result of passing the required natural weathering test); and some recycled composite materials.
It can sometimes be difficult to tell whether a roof is Class A or not. Even a homeowner may not know the classification of their own roof. In this case, the manufacturer of the roof covering can tell them. If you don't know the name of the manufacturer, you may have to consult with a professional roofer.
|R2||Does the roof have any unstopped openings at the edge or ridge (e.g., open tiles)?||Stopped tile:|
|Wind-borne debris can accumulate under a clay tile barrel roof coverings or other openings at the edge of the roof. If accessible, birds can also build nests in the space between the roof sheathing and the bottom of the tiles, also providing combustible debris (fine fuels), that are easily ignited if embers are driven into the openings between the roof covering and sheathing.|
|R3||Is the roof in poor condition (e.g., broken pieces, open areas, badly curled shingles)?||Poor condition roof:|
|An older roof may lose some of its fire resistance characteristics with time. It is up to a homeowner to make sure their roof covering is inspected and maintained, and replaced when needed. When new, this asphalt composition roof covering has a Class A rating. The older, weathered roof may not provide the same protection from wildfire, and may also be more vulnerable to water leaks.|
|R4||Is there vegetation or other combustible debris in the roof valleys?||Debris in roof valley:|
|Another critical inspection and maintenance item for a roof is the removal debris (needles, leaves, and other combustible material) from areas where they naturally accumulate, and in gutters. Ignition of debris in these locations can ignite other roof components besides the roof covering - components that don't perform as well as a Class A roof. This issue is even more critical if the roof is something other than Class A.|
|R5||Does the roof have a 'complex design' where debris and embers can accumulate and possibly ignite adjacent combustible siding or other vulnerable components?||Complex roof:|
|The complexity of a roof is determined by how many levels and wall/roof intersections there are. A complex roof may include features like dormers and included windows, and roof to exterior wall intersections. The more complex a roof design, the more likely it is to have debris collection points, and therefore the need to ensure that it is debris free.|
|R6||Does the roof have open eaves (i.e., exposed rafter tails)? (If no, go to R7.)||Open eaves:|
|The eave occurs at the edge of the roof. Eaves usually project beyond the side of the building. Open, or unboxed, eaves can make a home more vulnerable to embers.||
|R6a||If yes, do gaps greater than ~1/8" exist between the blocking and rafters?||Gap in blocking:|
|With an open eave construction, blocking is installed between the rafters. Gaps greater than 1/8" can provide a location for embers to accumulate, and potentially gain access to the attic.||
|R6b||Are there vent holes in the between-rafter blocking?||Vent holes in blocking:|
|In open eave construction, blocking is installed between the rafters. Vent holes in the blocking (provided to allow air entry for drying and cooling in the attic space) also provides an entry point for embers to enter the attic.|
|R7||Does the roof have boxed-in (soffited) eaves? (If no, go to R8.)||Boxed eave:|
|The eave occurs at the edge of a roof. Eaves usually project beyond the side of the building. A boxed, or soffited, eave is enclosed.|
|R7a||Is there a vent in the soffit?||Soffit vents:|
|Entry of burning embers has been problematic for attic vents in general, and soffit vents in particular. There are several types of soffit vents, including the strip vents seen in the photo on the right, and the one in the photo accompanying question R7b.|
|R7b||Is the soffit material combustible?||Soffit:|
|If the soffit material is combustible, it is even more important that any vent screening is well maintained and that combustible vegetation is cleared from around the soffit area.|
|R8||Is the chimney opening unscreened?||Screened chimney:|
|In the case of chimney screening, it is more of a concern that embers not be able to leave the chimney (and spreading fire to the wildland area) than that embers enter the home through the chimney in the event of a wildfire.|
|R9||Is there debris in the roof gutters?||Gutter debris:|
|Combustible debris can build up in gutters, especially from nearby or overhanging trees. Second story gutters are even more problematic, since they are seldom cleaned on a regular basis. If ignited, combustible debris in the gutter will expose the edge of the roof covering, and may be able to more easily enter the attic. Even screened gutters must be routinely maintained.||
|R10||Is there any vegetation near the roof or roof edge (overhanging, underneath, or adjacent to)?||Vegetation near roof:|
|Not all plants are strictly ‘good’ or ‘bad’. The size, location, structure, and condition of vegetation determines its risk to a home. Plants or trees located closer to a home are will pose a greater risk. Some trees farther away can sometimes serve as buffers against radiant and convective energy, and fire brands (embers). However, any trees or other vegetation within 6' of the roof should be pruned, regularly watered (preferably by incorporating into a drip irrigation system), and any dead material removed, including debris at the soil level.|