Is James Hardie Siding Fire Resistant?
Fibre cement doesn’t burn. That’s a real advantage, and it’s worth understanding exactly what it does and doesn’t mean for your house.
The short answer
James Hardie fibre cement siding is non-combustible. It’s made mostly of cement and sand, so it won’t ignite when exposed to flame and it won’t add fuel to a fire. That sets it apart from claddings that melt, burn or feed a fire once it reaches the wall.
Why this matters in Alberta
Recent wildfire seasons have made exterior fire resistance a practical question, not a theoretical one, for communities on the edge of the city and in the foothills. It also matters in ordinary neighbourhoods. Houses in newer subdivisions sit close together, and a fire in one can spread to the next through heat on the side wall. A barbecue too close to the house is another everyday risk.
The City of Calgary’s climate-ready home guide lists fibre cement among the more resilient siding options for wildfire, alongside hail and wind.
What non-combustible doesn’t mean
It doesn’t make a house fireproof. Siding is one layer of the exterior. A fire can still get in through other routes, and intense heat can affect what’s behind a wall even when the cladding itself isn’t burning. It’s better to think of fibre cement as removing one common way for fire to take hold.
The other parts of a fire-resilient exterior
- Roof. The largest surface exposed to embers. Roofing material and its fire rating matter a great deal.
- Soffits and vents. Embers get drawn into attic vents. Non-combustible soffit such as HardieSoffit helps, and so does appropriate vent screening.
- Eavestrough. Dry leaves and needles in gutters ignite easily. Keep them clean.
- Windows and doors. Heat can break glass and let fire in.
- Decks and fences. A wooden deck or a fence attached to the house can carry fire straight to the wall.
- The first metre and a half around the house. Keep it clear of bark mulch, dry plants, firewood and stored items.
FireSmart guidance covers these in detail and is worth reading if you live near grassland or forest.
Trim matters too
If the siding is non-combustible but the corner boards and window surrounds are wood, the wall still has fuel on it. Using fibre cement for trim as well, such as HardieTrim, keeps the whole surface consistent.
Does it affect insurance?
Some insurers take exterior materials into account and some don’t. We can’t tell you how yours does. It’s a fair question to put to your broker, especially if you’re in an area with wildfire exposure.
Everyday fire sense
Even with fibre cement, keep barbecues and fire pits away from the walls, as the manufacturer of the appliance recommends. High heat close to any siding can damage the finish, and you still have trim, soffits and windows nearby.
More on local conditions: James Hardie siding and Calgary weather.