It’s not just California anymore: Wildfires now pose a significant threat to homes and communities across the U.S. In recent years, wildfires have posed serious problems in Hawaii, Colorado, and even the Canadian tundra. However, with proper preparation and maintenance, homeowners can significantly reduce their risk of fire damage. Choosing fire-resistant roofing and siding and making smart landscaping choices can offer your home substantial protection.
In this video and guide, This Old House host Kevin O’Connor explores wildfire safety measures with Dan Gorham, a former firefighter and research engineer. Below, we’ll list those safety measures and offer additional resources to help you keep your home safer.
Understanding Wildfire Risks
Contrary to popular belief, the primary threat to homes during wildfires isn’t a wall of flames. Long before these flames reach your home, the real danger comes from flying embers.
The Role of Embers
Embers, also known as firebrands, can travel far ahead of the fire front. These small, burning particles can ignite combustible materials on or near a house, leading to its destruction.
Several parts of your home are particularly susceptible to ember ignition:
- Roofs
- Gutters
- Siding
- Decks
- Landscaping
According to California building codes for the wildland-urban interface, flying embers can travel as far as a mile ahead of the fire front. As reported in This Old House Magazine, these codes now address more than 300 building-product categories—from adhesives to roofing, siding to skylights—all aimed at reducing a home’s vulnerability to flames, radiant heat, and airborne embers.
Protecting Your Roof from Catching Fire
According to the U.S. Federal Emergency Management Agency (FEMA), the roof is one of the most critical areas to protect, as it’s a large horizontal surface that can easily catch embers.
When selecting roofing materials, opt for those with a Class A fire rating. This rating indicates the material can withstand fire exposure for two hours or more before burning through to the sheathing. Some examples include:
- Asphalt shingles (most are Class A rated)
- Metal roofing
- Tile roofing
- Slate
Even with a Class A rated roof, proper maintenance is crucial. Regularly clear your roof and gutters of debris such as leaves and pine needles, which can act as kindling if ignited by embers. Also, seal any gaps or roof penetrations with fire-resistant mortar, caulk, or expanding foam.
The roof surface and gutters aren’t the only features that need safeguarding. FEMA recommends installing metal screens on attic and under-eave vents. The mesh should be no larger than one-eighth of an inch to effectively keep embers away from the wooden structures within a roof.
During a This Old House project in Paradise, California, the team observed a live fire test on a Class A rated asphalt shingle roof assembly. As the flames burned on the surface, host Kevin O’Connor noted the key insight: “It’s a race against time, right? Because this will burn itself out. So if this surface can last long enough, it’s okay to have a fire. It just won’t get through.” Research engineer Daniel confirmed: “It’s the idea of resistance, where the fuel on top doesn’t burn long or hot enough to burn through and into the building.” The test demonstrated that even as the shingles began to melt and break down, the underlying felt layer and plywood sheathing remained intact—exactly the kind of performance a Class A rating promises.
Safeguarding Your Home’s Exterior by Improving Wildfire Resistance
The exterior walls of your home are another vulnerable area that requires attention to improve wildfire resistance.
In fire-prone areas, avoid wood shakes, shingles, and clapboard as well as vinyl, which can melt. When possible, choose non-combustible siding materials such as:
- Brick
- Stucco and masonry
- Stone veneer
- Fiber cement board
If you want the classic look of wood, fiber cement board, as Gorham demonstrates in the video, can mimic wood’s appearance while providing superior fire resistance. Once again, seal all gaps, including utility-line penetration, with fire-resistant caulk.
Of course, replacing a home’s entire siding comes with a considerable expense. For homes with combustible siding, a cost-effective solution is to replace the lower six to 12 inches with a non-combustible material. This acts as a fire block between the foundation and the framed walls, a space where embers may collect.
In Paradise, California, the difference fire-resistant building codes can make was starkly evident. Between 2008, when California updated its building code for fire-prone areas, and the devastating Camp Fire, the town had 350 homes built to the new code. Half of those survived the fire. By contrast, only 18 percent of homes built before the new code survived—a powerful argument for upgrading your home’s exterior materials even before a wildfire threatens.
Pro Tip: Dan Gorham, former firefighter and research engineer, recommends that if you can’t replace all your combustible siding, focus on the most vulnerable area: “If you have a combustible siding, you can maybe remove the lower six inches where embers would accumulate and might cause” ignition. This targeted approach gives you meaningful fire protection without the cost of a full siding replacement.
Creating Defensible Space Around Your Home With Vegetation
Proper landscaping also plays a crucial role in protecting your home from wildfires. Gorham explains the concept of defensible space, which involves creating zones around your house with different levels of vegetation and combustible materials.
Zone 1: 0–5 Feet from the House
This immediate area around your home should be free of combustible materials. Remove wood mulch and replace it with rock mulch or gravel. Avoid planting any vegetation in this zone, and keep this area clear of flammable items like firewood or propane tanks.
Zone 2: 5–30 Feet from the House
In this zone, you can have some vegetation, but you should plant and manage it carefully. Space plants and trees to prevent fire from jumping between them, and choose low-growing, fire-resistant plants.
Regularly prune and maintain vegetation, and stack any woodpiles on non-combustible materials or in an enclosed shed.
Zone 3: 30–100 Feet from the House
While this zone allows for more natural growth, you should still maintain it with fire safety in mind. Trim low branches on tall trees to prevent fire from reaching the crowns. Maintain spacing between trees to reduce fire intensity, and remove dead or dying vegetation regularly.
Additional Wildfire Protection Measures
Beyond the main areas discussed, there are several other steps to enhance your home’s wildfire resistance.
Addressing Vulnerabilities in Windows
Windows can also be entry points for embers, so consider installing fire-resistant shutters. Dual-pane windows with tempered glass will protect your home from radiant heat and also offer better energy efficiency than single-pane glass.
Protecting Decks and Patios
Wooden decks can be particularly vulnerable to wildfire, so take steps to protect these outdoor features.
- Use fire-resistant decking materials when possible, either synthetic materials or chemically treated, UL-approved lumber.
- Keep the area under decks clear of debris and vegetation.
- Consider enclosing the underside of decks with fire-resistant materials.
Emergency Preparedness
Beyond safeguarding your home, you should also take steps to prepare yourself and your family for a potential evacuation. Create an emergency kit with essential supplies, and develop and practice a family evacuation plan. Make sure your street sign and property numbers are easily visible to firefighters, and stay informed about local wildfire conditions and warnings as well as the USGS Fire Danger Forecast.
Pro Tip: Don’t overlook your gutters—they can become a tinder bundle during a wildfire event. As demonstrated on Ask This Old House, installing ignition-resistant gutter guards with a micro-mesh design keeps dry leaves out while still allowing water to flow through. The raised pattern breaks the surface tension of the water and adds structural rigidity to the guard, making it both functional and low-maintenance.
Our Conclusion
Protecting your home from wildfires requires a multi-faceted approach, encompassing fire-resistant building materials, proper maintenance, and defensible landscaping. By implementing these strategies, homeowners can significantly reduce their risk of wildfire damage and increase their peace of mind during fire season.
Expert assistance with this segment was provided by the Insurance Institute for Business & Home Safety.
