If you have lived in Kelowna for a while, you know the feeling. The sky turns orange, the air gets thick, and you start looking at your house differently. The Okanagan Mountain Park fire in 2003 forced more than 27,000 people from their homes and destroyed 239 homes on the southern edges of Kelowna, according to the City of Kelowna. In August 2023 the McDougall Creek fire hit West Kelowna and the surrounding area, and early estimates put the number of structures lost or damaged at fewer than 190.
You cannot control the weather or the forest. You can control what your house is made of. That is what this post is about.
1.How Homes Actually Catch Fire
Most people picture a wall of flame coming down the hill. FireSmart BC says embers are a key way homes ignite. Sparks and burning embers can travel long distances, up to two kilometres ahead of a wildfire, and ignite flammable materials on or near your home.
That is why the outside of your house matters. The roof, the siding, the gutters, the eaves and the vents are all places an ember can land or get in.
2.What Non-Combustible Means
A non-combustible material will not ignite and will not feed a fire. That is different from a material that is only fire resistant, which slows a fire down. Steel, aluminum, fibre cement, stucco, brick and concrete are the materials most often used on the outside of a home for this reason.
3.Fire Resistant And Non-Combustible Options For Your Home
- Metal roofing: FireSmart BC lists metal as a Class A fire rated roofing material, the highest class. Clay tile and concrete tile are on that list too.
- Fibre cement siding (like James Hardie): James Hardie says its siding is made of Portland cement, sand, water and cellulose fibres, will not ignite when exposed to direct flame, and will not add fuel to a fire. Their fire resistance does not extend to paint or coatings, which can char.
- Metal siding (steel and aluminum): FireSmart BC lists metal siding, stucco, brick, concrete and fibre cement as offering superior fire resistance.
- Stucco, brick and concrete: Traditional cladding with the same superior fire resistance.
- Metal gutters and downspouts: FireSmart BC recommends non-combustible gutters such as galvanized steel, copper and aluminum.
- Metal vent screens: FireSmart BC recommends 3 millimetre non-combustible wire mesh, or fire rated vents.
4.Combustible Or Higher Risk Products Still On Many Homes
If your house has some of these, you did not do anything wrong. A lot of homes in the Okanagan were built with them. It just helps to know where you stand.
- Untreated wood shake roofs: FireSmart BC rates untreated wood shakes Class C, the weakest class, because they combine combustible material with crevices where embers can lodge.
- Wood siding, including cedar: FireSmart BC says untreated wood and vinyl siding offer very little protection against wildfire.
- Vinyl siding: It can melt when exposed to high heat, which can let fire reach the wall behind it. Radiant heat alone can melt it.
- Unscreened vents: They let heat and embers into the building.
- Open eaves and soffit vents: FireSmart BC says soffit vents can pull embers in, and recommends screened vents and boxed in eaves.
- Gutters full of dry leaves and needles: Debris in gutters can ignite.
One more thing worth knowing. Asphalt shingles are on FireSmart BC's list of Class A roofing, so they are not in the high risk group. A Class A rating applies to the roof as a whole assembly, including the sheeting, drip edge and end caps, so the details matter.
5.The Small Things That Matter
A strong roof can still lose to a gap. Screened vents, tight flashings, clean gutters and a clear zone around the house all help. FireSmart BC recommends a 1.5 metre non-combustible zone around your entire home and any attachments, made of soil, rock or stone with no plants, debris or combustible materials.
6.Is It Worth Upgrading?
Every home and budget is different, and you do not have to do everything at once. A common approach is to start with the roof, then move to siding, soffits and vents. It is also worth talking to your insurance provider. After the 2003 fire, insurance industry people said many of the homes that were lost were underinsured, and the fire cost the industry more than $200 million in insured losses.
The goal is simple. Give embers nothing to catch on.
Sources
- City of Kelowna: Okanagan Mountain Park fire
- Castanet: Fewer than 190 structures lost, damaged in McDougall Creek fire
- FireSmart Canada Home Development Guide
- FireSmart BC Homeowner's Manual
- James Hardie: What is fiber cement siding
- Canadian Underwriter: What the industry learned from a 20 year old wildfire