Choose Fire-Resistant Construction Materials for Your Next Building Project

When a fire strikes, the damage to your ministry extends beyond the flames. Your fire suppression system could cause thousands of dollars in water damage. Smoke damage could affect the entire building, and the resulting repairs can leave your meeting space unusable for months on end. That’s why it's important to make construction decisions early in the process that protect your ministry from potential fires—both those that start inside your ministry and those that start outside, like wildfires.

The Insurance Institute for Business & Home Safety® (IBHS) does extensive research on building safety and natural disasters to identify solutions that will help create more resilient communities. If you’re in the planning stages of constructing a new building, IBHS recommends paying attention to the following areas that are most vulnerable to fires:

Roof
Under-Eave Areas (Soffits)
Exterior Walls & Windows
Decks
Landscaping

As you consider the various options available for roofing, walls, and even landscaping, choosing resilient, fire-resistant materials can reduce your risk of fire damage in the future. By making these decisions at the beginning of the construction process, you can save your ministry thousands of dollars—and improve the likelihood of your building’s survival.

ABCs of Resilient Roofs

In less than a minute, a small flame can turn into a raging fire. Without resilient materials, your roof becomes the end of a matchstick. Once a roof ignites, the rest of a building is quick to follow.

“Roofs are vulnerable to ember accumulation if a fire is nearby, and their large surface area makes them especially susceptible to damage,” said Robert Silber, a senior risk control specialist with Brotherhood Mutual. “Even if a fire does not occur directly on your property, windblown embers could still carry a threat, landing on shingles and gutters in droves before finally igniting.”

Roof coverings with exceptional fire ratings provide the highest protection against fires. Materials receive one of three class ratings based on their ability to resist the spread of fire and embers. Class A provides the highest protection, and Class C provides the least.

Class A

Survives a severe fire test
Can endure two to four hours of exposure before ignition
Includes most asphalt shingles, tile, slate, and metal roofs, along with built-up and single-ply membrane roofs
Recommended for use in commercial buildings and residential buildings

Class B

Survives a moderate fire test
Can endure one hour of exposure before ignition
Includes materials like pressure-treated shakes and shingles
Not recommended for use in commercial buildings or residential buildings

Class C

Survives only a light fire test
Can endure 20 minutes of exposure before ignition
Includes materials like untreated wood shakes and shingles, plywood, and particle board
Not recommended for use in commercial or residential buildings

Roof covers aren’t the only thing to consider when you’re planning your roof construction. Using underlying materials or special installation techniques for increased protection can improve a roof rating. For example, a metal roof material may be susceptible to melting, so it wouldn’t have a Class A rating. However, if an additional fire-resistant material, such as noncombustible fiberglass or mineral wool, is installed underneath it, the roof may achieve a Class A rating. When looking at roof cover systems, it is imperative to look at the entire assembly of its components to verify that it meets a Class A rating.

Don’t Underestimate the
Under-Eave Exposure

It might be easy to miss the overhanging portion of your roof that extends past exterior walls, but this space is a prime entryway for smoke and embers. You can help keep your building from becoming a fiery furnace by ensuring that your building’s eaves are enclosed and taking steps to make this area resilient. Particularly in wildfire-prone areas, it is important to adhere to local building codes, which often includes installing fiber-cement ventilated soffit material.

The fascia board, which is the place where gutters attach to your building, should be covered with a fire-resistant siding.

“For the fascia system, it’s best to use something like aluminum or concrete and avoid materials like vinyl and wood,” said Silber. “Resistant materials are good to have behind your gutters because they have the added advantage of reducing water behind the gutters that might result in damage.”

As you plan your construction, be aware of your options for soffit materials Although plywood and vinyl are commonly used, they do not provide much protection in a fire and are likely to ignite or melt more quickly than resilient materials. Instead, consider using noncombustible options:

Metal
Cement
Stucco

It’s also important to consider the exposure of under-eave vents. When left uncovered, these vents could provide openings for embers to reach the attic and ignite. Installing a screen of 1/8-inch or 1/16-inch metal wire mesh on all vent openings can prevent embers from entering and starting a fire from the inside.

Roof Vents & Edges

Windborne embers can enter the building through unprotected vents and start a fire. Cover roof vents with noncombustible 1/8-inch or 1/16-inch stainless steel wire mesh to prevent embers from entering your building. Roof valleys, gutters, and the area under roof-mounted equipment tend to collect debris that can ignite from traveling embers. Routinely ensure these areas are free from all debris. Additionally, consider using a noncombustible material for gutters to reduce the likelihood of them melting. Gutters made from galvanized steel, copper, or aluminum will not ignite in the event of a fire. It’s also a good idea to use protective coverings on gutters to prevent flammable debris and vegetation from collecting there. If the roof has clay tiles, it may have openings between the top of the tile and roof deck at the roof edge or ridge. Make sure those are plugged using a noncombustible material; this is often referred to as “bird stopping.”

Creating a Tough Exterior

The exterior of your building comprises not just your siding, but also the windows and doors. According to IBHS, exterior walls should be constructed with noncombustible materials. Some options include:

Concrete blocks
Stone
Fire-retardant treated wood
Aluminum siding
Brick

Extreme temperatures from a fire can cause glass to break and deform vinyl window frames. Choosing resilient materials for windows can reduce the risk of them breaking and allowing flames to enter your building. As you think about what kind of glass and frame to install, keep in mind that IBHS says you can reduce exposure to fire risk by using one of the following glazings with a non combustible metal frame.

Multi-pane glass with at least the outer pane tempered
Glass with a minimum of a 20-minute fire-resistance rating when tested in accordance with NFPA 257
Glass blocks

Dealing with Decks

Decks provide a great opportunity for gathering during ministry events, but they can also pose a risk due to their size and potential for collecting debris. The large surface area can accumulate embers, and debris or vegetation under the deck may be combustible. You can minimize risk by enclosing the deck to reduce the amount of debris that builds up and by using noncombustible materials with high fire ratings.

Autoclaved aerated concrete (AAC)
Aluminum decking
Composite decking
Fire-retardant treated wood.

Additionally, it is important to avoid using your deck area for any kind of storage. If combustible materials are stored on or under the deck, they pose a risk for igniting and causing a fire to spread.

Flora, Fauna, and… Fire

Vegetation and landscaping near your building could lead to disaster when fire spreads to your property. It is best to keep all combustible materials and vegetation at least five feet from the entire perimeter of your building. For example, bushes and trees should be far enough away that they do not pose a risk if they catch fire.

“Another thing to consider as you plan a construction project is whether there are any large trees surrounding the site,” said Silber. “If a tall tree catches fire and ends up falling, it could land on your building and spread the flames that way. You might want to cut down trees on your property that could pose a risk.”

Some other tips to keep in mind when planning your landscaping include:

Avoid putting shrubs and trees too close together. This helps prevent a fire from spreading.
Consider using high-moisture plants that grow close to the ground.
Use rocks and stones to create natural breaks in landscaping that could limit the spread of a fire.
Remove dead plant material and tree branches from vegetation regularly.

Making proactive choices to prepare your building for the future involves a lot of variables. As you consider what your ministry needs to maximize your protection against natural disasters, be sure to check out the Brotherhood Mutual resource page about choosing resilient construction. Additionally, it’s always important to talk to a local construction professional and your local fire marshal to make sure you’re adhering to building codes and using the best materials for your ministry.

Additional Resources:

Posted March 2024

The information provided in this article is intended to be helpful, but it does not constitute legal advice and is not a substitute for the advice from a licensed attorney in your area. We strongly encourage you to regularly consult with a local attorney as part of your risk management program.