Fire Demonstration: Hardie^® fiber cement stands up to the extreme

All it takes is a mistake in the kitchen or a mishap with an electrical device for your home to catch fire. Even if you take every precaution to avoid a fire inside your home, wildfires are a growing risk. As climate change leads to warmer and drier conditions, wildfire seasons are becoming longer and wildfires are becoming more extreme, according to research from the National Oceanic and Atmospheric Association.

In the past few years, wildfires have behaved in unprecedented ways, throwing embers across mountain divides and other barriers. Globally, forest fires have burned through nearly double the tree cover when compared to two decades ago. Areas where wildfires were once uncommon are now at risk. 80 million properties face a significant threat of wildfire exposure, with one in six Americans housed in a risky area.

Whether or not you live in an area that is prone to wildfires, it’s important to consider the risk of fire and take measures to protect your home. Working fire alarms are important, but they may not warn you about fires that originate outside. It’s also important to consider fire-resistant siding and soffit materials that can help defend against external flame spread, especially if you’re planning a re-side project.

The risk of combustible siding

Some siding materials are particularly vulnerable to fire. For example, wood siding fuels a fire, and vinyl siding melts when exposed to a flame, releasing toxic gasses and exposing other wood materials to flame. According to the Building America Solution Center, the following materials have low or medium resistance to fire:

• Solid wood siding
• Wood panel siding
• Wood-plastic composite siding
• Vinyl siding

In contrast, the following siding materials are rated for high fire resistance. 

• Fiber cement siding
• Metal siding
• Brick or stone
• Stucco

Of these siding options, fiber cement siding is often the most affordable. It also comes with a broader range of designs than other fire-resistant siding materials, and can even be combined with materials, like brick or stone, for an appealing design.

Further, the Insurance Institute for Business and Home Safety (IBHS) recommends enclosing open roof eaves with noncombustible materials, such as Hardie^® Soffit panels, adding strip vents near the overhang edge, and installing 1/8-inch mesh over vent openings as some of the most critical upgrades needed to reduce the risk of flying embers entering the attic space.

Building a wildfire-resilient house

While no exterior siding alone can ensure a home survives an external fire, noncombustible Hardie® siding provides protection superior to vinyl or wood-based siding. That’s because Hardie® siding will not ignite when exposed to a flame, nor will it contribute fuel to a fire. It offers the kind of durability you need to see to believe, and it’s captured in our fire demonstration video above. However, siding is only one element of a comprehensive fire mitigation approach.

This demonstration, conducted in a controlled setting, shows how a mock structure sided in Hardie®-^® siding remains intact, while the mock structures built with vinyl, engineered wood, and cedar siding eventually succumb to the flames. This demonstration is not intended to predict the performance of any specific wall design or siding installation on your home. Results may vary under different conditions. Noncombustible siding is only one of several elements that, in combination, may help reduce the risk of fire damage.

Since Hardie® siding and soffit panels are noncombustible, they may provide added peace of mind as part of a comprehensive fire mitigation strategy, especially if you live in a wildfire-prone area or are at risk for common household fires from outdoor grills and bonfires. Hardie® products have a Class A fire rating when tested in accordance with ASTM E84, with a flame spread index of 0. They’re also eligible to be used in certain 1-hour fire rated wall assemblies which may be required under local building codes. However, no siding can eliminate all risk of fire damage.

Choosing noncombustible siding and soffit panels gives you one less variable to worry about when hardening your home against wildfire damage. While it’s important to limit vegetation, wood mulch, and combustible structures on or around your home, noncombustible siding plays an important role in fire mitigation because it will not burn or add fuel to the flames.

Your dream home, fortified

Hardie® siding may be able to withstand a fire, but what about other weather events? The product has your back there, too. Hardie® products are specifically engineered to resist damage from moisture and rot, whether your home is hit with rain or snow. They also offer little appeal to pests and won’t be eaten by termites, unlike wood siding, which is more susceptible to damage from critters.
 
What’s more, the products are available in ColorPlus®-Technology finishes which come with paint baked-on at the factory. This finishing technique creates a stronger bond, with the paint resisting chipping, peeling, and cracking. ColorPlus® Technology finished products also resist fading from UV-rays better than vinyl siding.

While durability may be your primary concern as a homeowner, aesthetic appeal merits consideration as well. But Hardie® siding is far more than utilitarian — it’s also versatile enough to achieve the look of multiple siding styles, from board-and-batten to stucco-like finishes — and in gorgeous colors to boot. Download our inspiration guide to see what’s possible, or request a sample to experience the look and feel up close. And if you’re ready to install a product with superior fire resistance, request a quote.
 
For more, visit ibhs.org, fire.ca.gov/prepare, CalFire, or download the “Designing for Natural Hazards Series” publication from huduser.gov.

*Hardie® fiber cement products are noncombustible and/or have a Class A fire rating when tested in accordance with ASTM E84. Fiber cement fire resistance does not extend to applied paints or coatings, which may be damaged or char when exposed to flames. The use of noncombustible siding, combined with other fire mitigation measures, may help harden a home against external fire.