Is Your Home Hardened to Survive a Wildfire?
Fundamental Information
The term “fire hardened” means your home is prepared for wildfire and an ember storm. It does not mean fireproof. Home hardening addresses the most vulnerable components of your house with building materials and installation techniques that increase resistance to heat, flames, and embers that accompany most wildfires.
Learning to live with wildfire includes taking steps to reduce the risk to homes. Homes built to modern (2008 or later) building codes, with an adjacent and well-maintained defensible space, have a much better chance of surviving wildfire. Maintenance and upgrades to older homes can significantly improve the chance of your home surviving a fire.
Part of learning to live with wildfire is understanding that we have some control in how we prepare for and address this hazard, and how we manage fire in our individual communities.
The following fundamental information can help you better understand options for hardening your home and where to find more information.
How Homes Catch Fire
There are three ways your home can be exposed to fire, radiant heat, embers and direct flame contact.
Embers are small pieces of burning material that can travel more than a mile ahead of a wildfire. They can create spot fires when they land on combustible materials, such as leaves in your gutter or plants under your windows. Embers are responsible for most damage during wildfires. They can accumulate on your home, deck, or porch and ignite plants, mulch, leaves, fencing, or furniture. They can also be forced into gaps in the home (e.g. attic vents or an open or broken window) and burn the home from the inside out. When this happens, there can be little damage to the surrounding vegetation, leaving people puzzled as to what caused the home to burn.
Radiant heat generated from burning structures or plants can be hot enough to ignite a house without direct flame contact. This is particularly challenging in densely populated areas, where the heat from one burning home can ignite the next.
Direct flame contact can easily ignite your home depending on the time and exposure to radiant heat and/or convection heat from warm weather and/or a fire front. Even if the flaming front of a wildfire is not hot enough to ignite a house, the plants under windows ignited by embers or direct flame can break glass, allowing fire to enter the house.
Home and Property
We’ve learned from recent fires that hardening your home and keeping the 5 feet closest to your house clear of flammable materials (including patio furniture and décor) greatly improves its chance of surviving a fire. Maintaining defensible space is the law within 100 feet of a home in wildfire-prone areas, and highly recommended elsewhere. However, it is especially important to harden your home to reduce vulnerability to radiant heat.
Recommendations for Hardening Your Home
Reducing wildfire risks includes both maintaining defensible space and hardening your home. The top 3 things you can do to make your home more fire-resistant are to:
- Incorporate fire- and ember-resistant construction materials, installation details, and maintenance.
- Avoid combustible materials on the property, especially within the first five feet of the home.
- Be thoughtful about landscaping choices and maintenance.
Incorporating fire- and ember-resistant construction materials
The roof has the greatest exposure to fire embers. Replace a combustible roof with a tile, metal, asphalt, or other materials with a Class-A fire rating.
Crawl spaces and attics are particularly vulnerable. Embers can enter a crawl space and/or the attic, through vents. Upgrading vents with 1/8-inch metal mesh is also an economical way to reduce this risk. Installing WUI vents approved to resist embers and flames is a good way to reduce this risk too.
Eaves and soffits with gaps around exposed rafters and blocking of open-eave construction should be Caulked and plugged and wherever possible t is a good idea to fully enclose open eaves.
Fences or gates that connect to structures should have noncombustible materials within 5 feet of the building, to prevent the fence from burning up to the structure.
Chimney and stovepipe outlets should have an approved noncombustible mesh screen.
Rain gutters should be cleared of leaves and needles that embers can easily ignite. The installation of a noncombustible gutter guard to reduce accumulated debris will reduce the need to clean the gutters.
Garages are especially vulnerable because embers can enter a garage and ignite combustible contents destroying a house from the inside out. Installing weather stripping, or gaskets, around and under the garage door can limit ember entry.
Decks are vulnerable to fires from embers igniting vegetation or materials near or below them. Ensuring that all combustible items are removed from underneath, on, or next to your deck can reduce risk. The installation of a noncombustible layer between wood decks and siding is also helpful.
Siding is vulnerable if exposed to flames or radiant heat for periods of time. Plugging and/or caulking gaps and joints can reduce risk. It is also important to maintain 6 inches of vertical noncombustible material between the ground and the start of the siding. If possible, replace wood shingle or shake siding with ignition-resistant materials.
Windows can break from the heat, even before a home ignites, allowing burning embers or flames into the home. Ensuring there is no vegetation or other combustible materials within 5 feet of windows and glass doors is a simple way to reduce risk. Installing or upgrading to multi-pane tempered glass is an improvement that can reduce risk further.
Water supply for fire protection can be enhanced by having multiple garden hoses long enough to reach all areas of the structures on your property. Best practice in rural areas is to have a water tank with a 2½-inch fire department standpipe outlet for fire department use. Also, if you have a pool or well, it is a good idea to have a fuel-powered water pump available.
