Home hardening means using fire-resistant building materials and landscaping to protect buildings from heat, flames and a blast of embers during a firestorm.
Here’s a brief overview of what that involves:
Roofs: “Class A” roofing, which provides the best fire protection, includes asphalt fiberglass composition shingles, concrete or clay tiles and some metal roofing materials. Gaps and ends need to be plugged.
Rain gutters: Fire-resistant gutters are made from metal or another non-combustible material. A non-combustible gutter cover also reduces debris. A metal drip edge covers the space between the roof and the gutter.
Exterior walls: Siding needs to be able to withstand flames and heat for up to an hour. Noncombustible siding includes stucco, steel, fiber cement and specially treated wood.
Windows: Dual-pane windows with one pane using tempered glass that won’t shatter during a fire. Screens can catch embers and reduce heat.
Vents: Ember and flame-resistant vents come equipped with mesh enclosures of 1/16th to 1/8th of an inch. Some vents use “intumescent” material or paint that expands when exposed to high heat and seals off the opening.
Eaves: Boxed in eaves using ignition-resistant or noncombustible materials eliminate space wheres embers can can collect.
Decks: Use fire-resistant material and enclosed openings around the perimeter to keep embers from collecting underneath.
Landscaping: Reduce flammable materials and vegetation within 100 feet of the home. Defensible space is divided into three zones:
—The ember-free zone, or Zone 0 (within 5 feet of the home): Use non-combustible material like stone, pavers or concrete around the home’s perimeter. Replace flammable fences, plants and furniture next buildings with non-flammable materials.
—The green zone (from 5 to 30 feet of the home): Plant just a small amount of vegetation in separate islands and keep it green. Remove dead vegetation and flammable materials.
—The reduced fuel zone (from 30 to 100 feet of the home): Remove dead plants, shrubs, small trees, lower tree branches and other “ladder fuels.” Locate storage buildings, sheds and propane tanks at least 30 feet from the home and create an ember-resistant zones around them.
For more information, see the state Fire Marshall’s products handbook.
Sources: CalFire’s home-hardening websites, which can be found here and here; the Insurance Institute for Business and Home Safety; the Wildfire Home Retrofit Guide; Bob Raymer, building code consultant for the California Building Industry Association and the California Apartment Association; and Kelly Berkompas of Brandguard.