Home Hardening
What is Home Hardening?
Home hardening is installing or retrofitting a home with ignition-resistant materials. When hardening a home, consideration should be given to the three heat transfer mechanisms: embers, radiant heat and direct flame contact. Remember: embers can travel more than a mile away from the fire.
On this page you will find information on steps you can take to harden your home. You can also schedule a site visit to gain site- specific recommendations for home hardening and Home Ignition Zone recommendations. More information can be found at FireSafe Montana Ignition Resistant Construction Guide
Class A roof example
The ABC's of Roofs: Roofs are highly vulnerable to wildfire ignition. Many homes that ignite in wildland-urban interface fires burn from the top down; this is a result of the roofing materials or the combustible roof decking. There are three classifications of ignition-resistant roofs: Class A, B and C. The classification refers to the roof's effectiveness to fire severity tests.
Class A: Can withstand high severity fire tests. Highly Recommended. Roofing materials include:
Asphalt shingles
Metal/stone-coated material
Concrete (standard weight and lightweight)
Clay tile
Synthetic
Slate
Hybrid composite
Remove debris, like needles, branches, and leaves, on the roof and in the gutters yearly ideally. Ensure there are no missing shingles or gaps in the roofs. Birds and rodents can build nests in this gaps, creating a fuel source. Also, embers can penetrate through those gaps.
Vents, Eaves and Crawlspaces: Major point of entry for embers. To reduce the size and number of embers that enter your home, install an 1/8" metal screen over your attic vent. Research shows that embers that are less than 1/8" do not have enough heat energy to ignite a combustible (insulation) present in an attic. Avoid using the attic as storage space of combustible materials. Where to install screens:
Attic vents and other vents around the house
Crawlspaces like under a deck, soffits and eaves.
Cement Board Siding
Windows and Frames: Double-pane windows are the new standard of construction. Using tempered pane windows are also recommended. Window frames should be composed of ignition-resistant materials. Extreme temperature fluctuations cause windows to break or crack. Incorporate a metal sub-frame to help the frame retain it's shape when exposed to extreme heat.
Exterior Siding and Walls: Because the home's siding is typically the largest overall surface of the home, the material used in the home's siding plays a significant role in reducing the effect of a fire. There are a variety of ignition-resistant siding products available. Stone/rock, stucco and cement board are recommended products for creating ignition-resistant structures. Devote special design attention to the underside of overhangs (roof soffits, cantilevered balconies, decks, and underfloor areas) because here is where flames will be trapped and temperatures will be the highest. Heavy timber construction is another ignition resistant material.
Decks: Many decks that ignite are due to direct flame contact from materials stored under the deck that catch fire. There are two main types of deck materials: wood and composite or PVC. Drying or splitting wood is a common concern with decks, because the cracks catch embers easier.
Gutters: Gutters should be composed of non-combustible materials and installed such that the leading edge of the roof is finished with a metal drip edge so that no wood sheathing is exposed. The debris gathered within the gutters (needles, leaves, etc.) are the main source of ignition. If possible, use a gutter cap to prevent debris from accumulating in your gutters.
Chimneys: Installing spark arrestors on existing chimneys is highly recommended. These are meant to prevent a wildfire from starting due to embers from wood burning appliances.
Spark Arrestor on Chimney