Protect Your Eaves, Soffits, Vents, and Gutters from Wildfire

04/18/2023

Protecting your home's eaves, gutters, soffits, and vents from wildfire is crucial to prevent wildfires. Evaluate and modify these building components to keep wildfire embers from entering and igniting your home.

What do I need to know?

Eaves, Overhangs, and Soffits
Eaves, overhangs, and soffits are not typically fabricated with fire-resistant materials. That is why they pose a potential hazard in wildfire-prone areas. These critical home components, including those made with thin metal, untreated wood panels, and vinyl material, are highly vulnerable to wildfire because they melt or ignite, allowing the fire to spread onto the roof, into the attic, or onto and through the exterior wall.
Overhangs and the top part of exterior walls can trap windborne embers, convective heat, and radiant heat, so it is critical to construct overhangs and walls using noncombustible or fire-resistant materials.

Vents
There are various types of vents in a home, including vents for attics; ventilated cathedral ceilings; crawlspaces; and heating, ventilation, and air conditioning (HVAC) systems. During a wildfire, embers and hot gasses can enter vent openings and attic spaces, crawlspaces, and ductwork, spreading fire to the interior of your home. Dust, lint, and other debris collected at vent openings can also catch fire.

Gutters and Downspouts
Gutters and downspouts fabricated with plastic can melt during a wildfire.
Branches, leaves, pine needles, and other debris and vegetation trapped in gutters can catch ignite, create a fuel path, and spread wildfire to the roof.

Where do I start?

1. Remove debris from your gutters, soffits, and vents, such as leaves, twigs, and branches.
2. Install fine mesh screens over your vents, gutters, soffits, fireplace chimneys, and the underside of above-ground decks to keep embers out. Use non-combustible mesh no larger than 1/8 inch in size.
3. Enclose eaves, fascia, and soffits with noncombustible materials to reduce the size of the vents or openings to prevent firebrands from entering the structure.
4. Do not use polyvinyl chloride (PVC) or vinyl siding; they can melt in a wildfire and allow embers to enter the attic space.
5. Consider a home design without or with minimal overhangs to avoid the potential fire risks with soffits and the potential for trapping embers and hot gases. If you have a roof overhang or large overhang, take the following steps:
   • Use soffits rated for minimum one-hour fire resistance. This will help stop embers and hot gases from making contact with the joists, rafters, trusses, or the underside of the roof decking.
   • Use flat, horizontal soffits instead of attaching the soffits to the sloped joists.
   • Use noncombustible or fire-resistant fascia materials.
6. Seal any gaps or cracks around your eaves, soffits, and vents with a fire-resistant sealant. This will prevent embers from entering your home through these openings.
7. Use fire-resistant materials for eaves, soffits, and vents. Metal, cement, or stucco can be good choices.
8. Use noncombustible materials for gutters and downspouts, as those fabricated from galvanized steel, copper, and aluminum will not ignite.
9. Install non-combustible leaf guards over gutters, including metal-mesh screens and hood types. As debris can still accumulate on top of the leaf guards, clean them regularly and remove all debris.
10. Never plant trees under your roof overhangs. Trim back any existing trees and branches that drape over your roof and eaves.
11. Keep a defensible space around your home by clearing any ignitable materials, such as dry leaves or branches, within 30 feet of your home.
    Take all these steps to protect your eaves, gutters, soffits, and vents, and you will reduce the risk of your home igniting during a wildfire.

Resources and References

FEMA P-737 Home Builders' Guide to Construction in Wildfire Zones
FEMA Rebuilding After a Wildfire
California Department of Forestry and Fire Protection: Wildfire Home Retrofit Guide
California Department of Forestry and Fire Protection: Readyforwildfire.org