In this fire demonstration video, you'll see how Hardie® Siding compares to vinyl, cedar, and engineered wood siding when exposed to direct flame.* The result: it doesn't burn.** It's a clear example of how our noncombustible fiber cement products react to flames — and why so many homeowners and builders choose them for exteriors in wildfire-prone regions.
Hardie® Fiber Cement is noncombustible and built to resist fire. Here are the four fire classifications that explain what that means.
A material classified as noncombustible won't burn or ignite when exposed to a direct flame, and won't contribute fuel to a fire. Hardie® Siding is verified noncombustible per ASTM E136 — and along with other home hardening measures, it may help resist damage from external fire.
A Class A Fire Rating is the highest classification under ASTM E84, indicating that a material has a flame spread index of 0 and a smoke developed index of less than 5 — meaning flames spread slowly across the surface and produce minimal smoke. Hardie® Siding carries a Class A Fire Rating, which is one of the key fire classifications behind its performance.
An ignition-resistant material is one that is difficult to ignite and resists the spread of flames when exposed to external fire. Hardie® Siding resists ignition when exposed to direct flame, which is why it's listed for use in wildfire-prone Wildland Urban Interface (WUI) zones in the western US.
WUI Compliant means a material is listed for use in Wildland Urban Interface zones — areas where residential development borders fire-prone wildland. Hardie® Siding is listed for use in WUI zones and has been verified in wall assemblies with 1-hour and 2-hour fire ratings per ASTM E119, making it an ideal choice for exteriors where structures meet fire-prone areas.
