To Resist Wildfire, Stop the Intruder at the Door
Californians have braced for another year of runaway wildfires, but this time, they’re better informed and better prepared.
Randall and Jill Hauser are often told they’re “lucky” because their home remained standing after the rest of their neighborhood was obliterated by the 2018 Carr Fire in California. Randall, CEO and founder of ENPLAN, an environmental and geospatial technologies consulting firm who designed the couple’s home, says it was more than luck that kept their home from joining the 12 closest homes as a pile of rubble and ash.
“My degree in architecture was nothing compared with the experiences of wildfire and extreme arid heat I accumulated simply living in Redding during the 12 years prior to the start of my house design in 1990 and construction in 1993,” says Randall. “My environmental planning, impact analysis and geospatial technology business helped enmesh me in these matters as well.”
Keeping vegetation away from the home is the first line of defense, but walls, roofs, and soffits must be made of fire-resistant materials as well.
Emphasizing fire and heat resistance in the context of the Redding climate resulted in a comfortable, practical, sustainable and attractive living environment, says Randall.
“The rest of the design is about creating defensible space and vegetation management in the least labor-intensive and affordable manner possible,” Randall says. “The less planted, the less there is to burn and the less there is to maintain, which also has its inherent benefits.”
While other states on the West Coast and in the Southwest are also at high risk for wildfires due to drought conditions and hotter weather, California’s conditions are worse than ever because the 2020-21 winter was one of the driest in history. The combination of climate change, housing built in high-risk areas and decades of inadequate forest management has increased the chances for another devastating wildfire season.
Here are 10 defense mechanisms to protect against wildfires. Some steps must be done during construction and remodeling, but others can be accomplished at any time.
- Landscape for fire protection. Cal Fire’s fire prevention and preparation site recommends keeping plants at least five feet away from the perimeter of the house and instead using hardscape like gravel, pavers, concrete and other noncombustible materials instead of combustible bark or mulch. Stone walls, patios and rocks can be used to create fire-resistant zones. You can also choose fire-resistant plants and shrubs that are high-moisture and have a low sap or resin content. Randall chose to create a 6-to-10-foot band of pea gravel, asphalt and paving around all structures on his property with minimal vegetation.
- Incorporate a water supply in your landscape plan. Randall has three standpipes for emergency structures on the perimeter of the buildings on his property, along with hose extensions and movable sprinklers. You can also install a Rachio smart irrigation system that provides a sustainable, app-controlled way to keep any plants on your property moist.
- Pick your siding carefully. Randall designed his home with a simple main structure to limit exposure and built it so 25 percent of the walls are underground, which gives a wildfire less of the exterior to engage above the groundline. In addition, his home and other structures on the property are covered with either stucco or steel, both non-combustible materials. Other materials that are fire-resistant include fiber cement siding, cultured stone or brick.
- Opt for an ember-resistant roof. A metal-clad roof with soffits, fascia and overhangs clad in metal can minimize the fire risk.
“Scores of spent wood embers along with burnt fragments of our neighbors’ asphalt shingle roofing landed on our metal roof still burning and leaving small puddles of soot and tar,” says Randall. “Our metal roof remained perfectly intact.”
- Choose non-combustible insulation materials. Designing a home with fire-resistant exterior materials and a metal roof protects the outside from fire, but you also need to carefully choose insulation for another layer of protection. For example, Rockwool’s stone wool insulation won’t ignite when exposed to flame and can prevent fire from spreading to other materials. The thermal insulation properties of stone wool help slow the transfer of heat, which provides a safety element to give residents more time to evacuate. Randall used an infrared barrier inside his home.
“The air temperature reached 140 degrees at the shell of my house,” Randall says. “That combined with radiation from thermal blasts could easily have raised internal wall temperature to ignition levels without the radiant barriers beneath the steel and stucco.”
- Install metal garage and fire doors. Metal doors on the garage and inside your home can prevent or delay the spread of flames. Add weather-stripping to keep embers out and store combustible items away from ignition sources.
- Cover your vents. While Randall designed his home without vents or openings that could allow an ember or spark into the house, if you have vents, Cal Fire recommends covering the openings with 1/16-inch to 1/8-inch metal mesh and installing flame-resistant vents. It’s best to avoid fiberglass or plastic mesh because they can melt and burn. Add a metal mesh screen to the top of your chimney and close the flue during wildfire season.
- Install dual-paned windows. Randall installed tempered glass windows with metal clad wood frames because the tempering resists shattering and the metal resists ignition. Cal Fire recommends dual-paned windows with screens to create a barrier to heat and embers.
- Keep your roof clean. Regularly remove any debris from your roof and gutters, especially during fire season, that could catch on fire and spread the flames.
- Maintain your grounds. Randall prunes branches from trees, removes dead limbs and trees, and keeps all grass cut within an inch of the ground as part of their seasonal maintenance. In addition, during fire season, any possible source of ignition such as door mats, shoes, boxes and chairs are removed along the edges of the home.
“A crucial factor going forward is the extent to which homeowner aesthetics and valuation criteria can evolve to reflect the reality of wildfire risk,” says Randall. “Traditional notions of beauty must be reformed. In short, when a built feature reduces wildfire risk, that feature must come to be seen and appreciated as beautiful. That is where my family has migrated its thinking. Not a hardship, but rather an exciting, mind-expanding and satisfying adventure.”