As this year’s wildfire season has shown us, wildfires and other natural disasters can dramatically affect the home security of our communities.
In this blog, we delve into the merits of fire-resilient construction, panning out the strategies that can help us build for the future with confidence.
No measure is guaranteed to fire-proof your home 100%, but there are steps you can take as a builder and homeowner to minimize the risk.
1. Selecting Fire-Resistant Materials
Traditional building materials such as wood frames or heavy timber can and often do contribute to the spread of fires. Building a fire-resistant home will require you to make a commitment to an array of adjustments in your approach to construction materials (and possibly aesthetics), some bigger than others. So, what can you do? Let’s dive in.
1.1. Install Fire-Resistant Windows
Fire can crack single glazed windows much more easily and expose your home to intrusive embers. Acrylic or wood will also burn or melt. Insulating with tempered glass and double glazing are much more likely to withstand the heat and prevent combustion. For even more improved fire-resistance, you may want to consider steel or aluminum frames.
1.2. Put in Fire-Resistant Insulation
Choose insulation materials that are fire-resistant or have a low flame spread rating, such as fiberglass (glass wool), cellulose, spray foam or rockwool. Make sure to seal all gaps and openings in the building envelope to prevent ember intrusion. And last but not least, it’s a good idea to put in a fire-resistant thermal barrier.
1.2.1 Consider Putting in a Fire-Resistant Thermal Barrier
A thermal barrier is typically used to enhance the fire resistance of spray foam insulation, also known as polyurethane foam. Despite its effectiveness and widespread use, it is essential to cover this insulation with materials like drywall, fire-resistant paint, or other building code-compliant substances.
A thermal barrier's purpose is to safeguard your home by reducing the flammability of the spray foam insulation. A structural barrier, like drywall, serves to slow down the temperature increase of the insulation in case of a fire, and it can also delay or possibly prevent direct contact between flames and the spray foam.
1.3. Non-Combustible Exterior
When it comes to exterior walls, you want to opt for non-combustible or fire-resistant siding materials such as stucco, brick, cement board, or metal panels. Metal siding, such as aluminum, does not catch or spread fire. Aluminum siding is sturdy and will also protect your home from heavy wind, rain and other natural hazards.
Fibre cement boards are unmatched for their fire resistance. These exteriors, comprised of cement, sand, and wood fiber, often boast a class A fire rating. However, fire resistance can vary among brands, so check the product description.
While fibre cement cladding isn't entirely fireproof, it ignites much more slowly compared to materials like wood or vinyl. Moreover, it can withstand several hours of continuous heat before melting. These qualities provide homeowners with valuable time to call firefighters and prevent irreversible damage.
Apply fire-resistant coatings to exterior surfaces to provide an extra layer of protection against radiant heat and flames.
While vinyl and wood siding may be versatile (and very much still in popularity), they are obviously both highly flammable and would not protect your house in the event of a fire.
1.4. Installing Fire-Resistant Vents and Eaves
Conventional eaves, overhangs, and soffits lack fire resistance, making them vulnerable to ignition from embers and hot gases. Once ignited, fire can quickly propagate to the roof, attic, or even through exterior walls. Soffits typically include vents for attic ventilation, but unprotected vents may permit embers and hot gases to infiltrate the attic.
Use vents with ember-resistant screens to prevent embers from entering the attic space, basement, foundation, and gable vents wherever you can. Pair that with fire-resistant eaves or soffits to reduce the risk of flames traveling from the ground to the roof. They’re also easy to install in retrofit.
2. Fire-Proofing by Creating
a Defensible Space Around Your Home
Creating defensible spaces around buildings is crucial to protect them from wildfires.
This involves maintaining vegetation-free zones of at least 18 Inches from your building (as the case of the sole-surviving house in Lahaina has shown). You can do this by using river stones, gravel, pavers, or other non-combustible materials to create firebreaks around your house.
For guidance specific to British Columbia, we recommend having a look at the FireSmart BC Landscaping Guide. Fire-resistant landscaping also involves, among other things, choosing plants high on moisture near and around the house, and avoiding fire-prone ones. We also recommend planting in small densities (consult a local landscaping company for best practices).
3. Fire-Proofing the Roof of Your House
Ember intrusion is a significant factor in the spread of wildfires. Proper roofing design, featuring fire-resistant underlayment, vents with ember-resistant screens, and fire-resistant eaves can help prevent embers from igniting the building. Use Class A fire-rated roofing materials, such as asphalt shingles, metal roofing, or clay tiles, which are less likely to ignite from embers or flames than shingles.
In addition, you can seal roof vents with ember-resistant screens to prevent ember intrusion. Install spark arresters on chimneys to prevent sparks from escaping.
4. Fire-Proofing can be Cost-Effective
The good news is, fire-proofing your home is very likely within your budget. A recent study commissioned by the National Association of Home Builders (US) found that chosen adjustments could range between USD $1,827 (cca. CAD $2,470) and USD $44,888 (cca. CAD $60,679). Another 2018 study by IBHS and Headwaters Economics that focused on California found that meeting wildfire-proofing standards can cost home builders and renovators roughly the same as costs are offset by choices in the building process. While Covid-19 may well have pushed these numbers somewhat, it’s safe to assume that building to fire-proof is an achievable goal for most.
5. Fire-Proofing with Water
and Power Generation
Installing sprinkler heads on your roof, balcony, patio or deck can be a game changer. You can program them to switch on and off automatically. Because fires are often accompanied by power outages, make sure your sprinkler system is connected to an independent power generator.
Most communities, unfortunately, lack the grid capacity to make measures feasible on a comprehensive scale. So, unless you have access to water from a private source, this one might be a bit tricky. If this is an option for you, it is definitely something to consider.
6. Community Planning and Collaboration are Key to Disaster-Proofing Homes
Building resilience against disasters isn't just about individual structures; it's also about community planning and collaboration. Engaging your local community in disaster preparedness initiatives enhances public awareness and fosters a sense of responsibility for disaster-resistant living.
Professional organizations can lobby municipalities to ensure that fire-resistant principles are integrated into building codes and community planning.
For more information on how you can fire-proof your home, check out BC’s FireSmart Home Guide.