What Is Fire Hardening?

Fire management specialist Tobin Kelley and a fellow officer were knocking on doors in the mountains around Colorado Springs in 2002, warning residents about the impending Hayman Fire, when they came across the most fire-hardened house they’d ever seen.

“The homeowners had cleared all of the vegetation out from a large diameter around the house, plus the house had been stuccoed, had a steel roof and steel shutters that could be swung over the windows,” says Kelley, who recently retired. “I thought, ‘This guy really knows what he’s doing.’

“It turned out he had experience in how fire reacts with wind and vegetation from being in the military, and applied it to protecting his house. His house is likely to survive any kind of fire, but that’s the extreme.”

Most of us can’t and won’t be that hardcore about fire hardening. Going that far is just too expensive and time-consuming. But anyone with a home in a wildlife risk zone should take action to keep their house safe.

What Is Fire Hardening?

Fire hardening means taking precautions to make your home less likely to burn down in a wildfire. Measures include moving combustible materials away from the house; clearing vegetation to create a defensible zone around it; covering vents with mesh to keep out embers; and changing structural materials, like switching to a metal roof.

Pros and Cons of Fire Hardening

Most fire hardening is helpful. But it should be done with forethought, taking into consideration impacts to the natural landscape and ecosystems, plus your financial resources.

Then there’s the other option. “Some people don’t bother to do anything,” says Kelley. “Maybe they figure they have good insurance. But those are the houses that firefighters have great difficulty protecting because fire has too many ways to ignite the structure.”

Pros

• Your home is less likely to burn down in a wildfire;
• Fire is less likely to spread to neighboring houses;
• A hardened home is safer and easier for firefighters to protect.

Cons

• Replacing structural materials like siding and roofs can be costly and change your home’s aesthetic;
• Fewer plants often lead to a less visually appealing yard;
• Fewer plants also takes away vital habitat for wildlife.

“It’s really important to be fire wise, but it doesn’t mean turning your yard into a moonscape,” says Marina Richie, a wildlife author and native plant gardener in Bend, Oregon. “Some people tear everything out, removing beautiful native plants like manzanita, bitterbrush and currants, but that’s where the quail, rabbits and chipmunks live.”

How To Know When Enough Fire Hardening Is Enough

There’s no quick answer, because there are so many environmental and structural variables. Think of it as finding a balance between fire mitigation, supporting wildlife and your own sanity.

“In a more heavily forested area, the ember shower is one of the worst things,” says Kelley. “I’ve been on fires where we’ve seen houses start on fire because embers got inside from some opening, even though the fire was still a quarter-mile away.”

So keeping embers at bay by screening vents, cleaning out pine needles from rain gutters and removing other combustible debris close to the house are among the most vital steps. After that, think about how a fire might move into your yard. Then design your strategy accordingly.

Tips for Fire Hardening Your Landscaping

Wind and terrain

Focus on the sides of your home facing the predominant winds. (In many areas, it’s the west and southwest.) If you’re on a steeper slope, start your efforts on the downhill side, since fire is more likely to move uphill. Avoid building decks that extend out over vegetation on steep hillsides.

Windows

Keep bushes and trees away from windows. If they catch fire, that can shatter the glass, which will let fire into the house.

Wood chips and mulch

Keep them away from the house. “They produce thick, heavy smoke that burns for days,” says Kelley. “You can’t see through the smoke, it’s hard to put out, and it’s really awful to be around.”

Native plants

Native species in your specific area tend to be more drought-tolerant and wildfire adapted. These plants also recover more quickly and their root systems are more robust, which helps the landscape recover faster.

But take care to keep plants with branches that go all the way to the ground, like Engelmann spruce, ornamental juniper and yew, away from your house. Consult a local native plant specialist to determine good fire-specific species for your area.

Extra water

“If the homeowner has extra water, that helps a lot,” says Kelley. A spare tank with a couple of hundred gallons or more in it gives firefighters something to tap into to put a sprinkler system around the house. You can also use it to water your landscaping. That’s important for fire hardening since dried-out and stressed plants are more likely to catch fire.