Fire-Resistant Building Materials & Home Hardening Techniques

Over 30 million homes are at low to extreme vulnerability to wildfires in California. If you live in an area affected by wildfires, using fire-resistant building materials and implementing effective home hardening techniques are two great ways to protect your home and belongings. Here’s everything you need to know.

Protect your home from wildfire by installing a Frontline Wildfire Defense exterior sprinkler system. For more information, contact us today for a free consultation.

Fire Resistant Building Materials

Renovating your home with fire-resistant building materials is an effective way to slow the spread of flames and reduce the amount of smoke created if a wildfire reaches your property.

Fire resistant building materials include:

• Fire-Rated Glass
• Concrete
• Fire Bricks
• Fire Retardant Wood
• Drywall Type X
• Fire-Rated Doors
• Dual-Pane Windows
• Treated Fibers
• Gypsum Board

These materials are designed to resist ignition in the presence of embers or even with direct fire exposure. Remodeling and reinforcing certain areas of your home with fire-resistant materials like these can significantly slow the spread of a fire. This allows more time for firefighters to put out the fire before extensive damage is caused—and in some cases, these materials may even slow the spread enough that the fires will burn out or move on without igniting your home.

Material Ratings

The American Society for Testing and Materials (ASTM) assigns fire ratings to materials based on their flammability. When looking for fire-resistant building materials, a “Class A Fire Rated” label, for instance, indicates that the material has the highest level of fire resistance.

These ratings are based on the organization’s flame spread index (FSI)—a measure of how quickly a material can burn and spread flames. The lower the FSI rating, the better the material is at resisting the spread of flames:

• Class A materials have an FSI of 0 to 25
• Class B materials have an FSI of 26 to 75
• Class C materials have an FSI of 76 to 200

For reference, lumber typically has an FSI of between 90 to 160, meaning it would fall in the Class C category. When building a new home or renovating, seek out materials with a Class A fire rating for the best protection.

Fire Proof vs Fire Resistant Materials

It’s important to understand that even Class A fire rated materials may only be fire resistant—not fire proof. While these materials may be more resistant to fire and slow the spread of fires, they can still burn. Even Class A materials are not sufficient if there’s ember ignition right against your home or in a roof valley that will eventually burn through the material. That’s why proactive hydration with an exterior sprinkler system is so important to protect your home from wildfires!

Home Hardening Techniques

A wildfire doesn’t have to reach your home to damage it. Drifting embers are the cause of 90% of destroyed homes in a wildfire and can travel several miles before landing and igniting a new fire on or near your property. By implementing the following home hardening techniques, you can help increase your home’s survivability and fire resistance, especially against drifting embers.

Protecting Your Roof

Your roof is one of the most vulnerable parts of your home, particularly if it is comprised of wood or shingles. To protect your roof against fires, consider rebuilding your roof with Class A materials, and avoid chemically treated materials or coatings. Metal and tile are two great, fire-resistant roofing alternatives to wood and shingles.

Install Fireproof Walls

Walls are often made out of wood materials that are extremely flammable, making them less than ideal for homes in fire-prone areas.

Installing fireproof walls around your entire home or around a designated safe room is a great way to slow the spread of fires and protect your valuables. Stucco, treated lumber, and concrete are effective alternatives to standard siding materials. You might also opt for fire-rated wall assemblies, which are pre-manufactured, ready-to-install fire-resistant wall kits.

In addition to rebuilding walls with Class A materials, intumescent seals or strips can help prevent smoke from passing through doorways.

Reinforcing Windows

Heat from fires can cause windows and other outdoor glass fixtures to break before the fire even reaches your home. Once broken, window openings make it easier for embers to enter and ignite within your home.

To protect against this, homeowners should install dual-pane windows to increase the time it takes for fires to break and spread through them. Using tempered glass will also help windows to resist fractures caused by heat.

Use Fire Resistant Fabrics

Commonly-used interior fabrics like cotton and linen ignite very easily and burn quickly. As an alternative, homeowners can use chemically-treated fabrics. Fibers like wool and cotton can be treated to reduce their flammability, making them safer to use in homes in fire-prone areas.

You might also consider avoiding lightweight, loosely-woven fabrics in favor of heavier, tightly-woven materials. Wool is a great natural fire-resistant option, while fire retardant polyester materials can also be an effective synthetic option.

Decks & Other Outdoor Surfaces

Any outdoor surface that is within 10 feet of your home is a potential fire hazard and should be treated as such. Consider rebuilding outdoor surfaces with Class A fire rated materials. This can give you enough time to either escape or put out smaller outdoor fires before they reach your home.

Other Considerations

Beyond the home hardening techniques mentioned above, there are additional steps you can take to create a safer, more fire-resistant home:

• Garage: Make sure to have firefighting equipment, such as a hose, bucket, shovels, etc. stored in your garage to help put out fires. Store flammable liquids and materials away from ignition sources.
• Gutters: Clean gutters regularly to prevent the build-up of flammable plant debris and vegetation.
• Chimney: Cover chimneys and stovepipe outlets with non-flammable screens to prevent embers from escaping and starting other fires.
• Vents: To prevent embers from entering through vents, cover vents with 1/16-inch to 1/8-inch metal mesh.
• Water Sources: If possible, install multiple garden hoses in different areas around your home so that they can reach any area in case of a fire.
• Driveways: Driveways should be built and maintained in a fashion that makes it easy for emergency services to access your property. Make sure any gates open wide enough for emergency vehicles and trim surrounding shrubbery to ensure the driveway is clear.
• Address: Make sure your home address is clearly visible from the road. This will make it easier for emergency services to find you quickly in case of a fire.

The Importance of Combining Home Hardening Techniques

None of the methods above is foolproof, and some are more effective than others. When used together, however, you can better reduce your risk. Simply put, the more protection you add, the greater the chances of protecting your home. According to data from CoreLogic, some of the most effective home hardening techniques include using Class A Roofing Materials (59% average annual loss reduction), installing an exterior sprinkler system (50% average annual loss reduction), and removing fuel sources from 30-100 feet around your home (31% average annual loss reduction).

* Data from CoreLogic U.S. Wildfire Model

From the same study, CoreLogic suggests that combining the best structure materials with a sprinkler system, defensible space, and community awareness can reduce average annual loss by 96%!

Install an External Sprinkler System