Have you ever wondered why some houses burn during wildfire events and others remain? How do close to 80% of home losses occur after the wildfire front passes? How can a single ember burn down an entire block of homes? Understanding the reasons behind residential fire losses to wildfire is essential not only for the residents of the home but every home within the community.
Here, we’ll look into the common causes of home losses during wildfire incidents.
Wildfire Threats and Ignition Sources: Where Fires Start
Almost all vegetation fires develop embers. Embers are carried aloft primarily by thermal lifting and wind. Heat rising into the atmosphere can carry embers hundreds of feet into the air. Furthermore, it is common for wildfires to create powerful winds as they move across the terrain.
A wildfire approaching a community is often preceded by the “Ember Front”. This is the equivalent of a snowstorm of embers raining down throughout the neighborhood.
The embers are seeking a safe harbor where they can land and find and environment conducive for growth. The ember is a heat source. In order to grow it needs oxygen and a readily available fuel source.
Homes that have cozy places welcoming embers and available fuel sources are the ones susceptible to burning during wildland fire situations.
Structural Vulnerabilities
The materials used in home construction can significantly influence flammability and how quickly a fire spreads. The roof covering is the first defense. Fire-resistive roof coverings such as clay tile, metal, asphalt shingles, recycled-rubber tiles, slate, and concrete tiles are all considered Class-A Roofing. They provide the highest level of protection from ember cast.
The siding of a home is the second defense against wildfire. Beyond brick, stone and adobe, stucco, aluminum, and fiber cement are all fire-resistive and protect against radiant heat as well as ember cast.
Embers love gutters and valleys in the roof design. The problem is all the flammable material that also loves to collect in gutters and the roof valleys.
Decks obviously capture embers as they settle back to earth. What’s not so obvious is the fine debris that collects in the gaps and cracks between wood decking. Over the years, leaf material and other flammables will collect between the decking boards. This is a fire trap and threatens the home.
House vents located under the roof eaves and along the foundation are also critical points of access to embers swirling in wind turbulence around the home. It seems incredible, but embers are small, and without proper screening, they can enter into the attic space or under the home in the subfloor. Once inside, they find a snug spot to retain their heat, and grow.
Prevention, Good Habits, and Home Hardening
Home hardening means taking steps to make a home more resistant to damage from wildfire. It may mean replacing flammable roof material and siding with fire-resistant materials.
But it doesn’t have to cost a fortune. Just keep it clean. We all tend to procrastinate when it comes to home maintenance. But what you do in the early spring may save your home and protect your family in the summer and fall.
Clean out gutters and remove leaves from the roof. Clean the deck of those leaves and pine needles hiding in the cracks.
The simple installation of fine, steel screens over eave and foundation vents can save your home by blocking embers.
Finally, we all love our stuff. It seems to be human nature to surround ourselves with possessions. Unfortunately, these possessions may pose a direct threat to our loved ones. Place outdoor furniture away from the house. Remove flammable materials from under decks. Collections of flammable materials against the home are ember catches and threaten everything. Finally, the definition of firewood is in the first syllable, “fire”. If you leave it against the house, you are inviting the fire to come on inside.
Defensible Space
Defensible space establishes a fire resistant zone around the home. It also provides access and a place from which firefighters can make a stand. This starts with the removal of vegetation and flammable materials from around the foundation of the home. Plant only species known for their fire-resistance. Separate shrubs and trees so that their crowns are separated. Finally, limb trees up off the ground, remove dead limbs, and remove unhealthy shrubs and trees. Keep the plants healthy, watered, and well maintained.
