Are you worried that if a wildfire or house fire reaches your home, your roof could help the flames spread instead of protecting your family? Have you been looking at fire-rated roofing materials but feel unsure whether choosing a Class A roof is enough to make your home truly fire-resistant?
At RoofSmart, we have been roofing in the Greater Seattle area for over 15 years. We have installed thousands of different types of roofs, including on homes in areas that are at a higher fire risk. As roofers, it is our job to make sure that your entire roof meets fire code requirements.
In this article, we'll explain what makes a roof fire-resistant, which roofing materials provide the best fire protection, how Class A fire ratings actually work, and the additional components your roof needs to help protect your home from fire.
When choosing a roofing material for your home, it’s important to consider the level of fire safety that it provides. You want to design your home and roof so that fire is not likely to continue spreading when it reaches your home.
This is important for those who live on the edge of town near the forest (also known as wildland urban interface zones) because fires can spread easily from there. You also want to make sure that a house fire doesn’t spread and turn into a wildfire.
Newer building codes require higher fire ratings on buildings, so it’s good to pay close attention to what helps to make your roof fire-resistant. A lot of roof materials are highly rated for fire resistance, but fire resistance depends on the entire roof assembly, not just the covering.
Here are the other assembly components that a roofer should consider when making your roof fire-resistant:
|
Roof Component |
How It Improves Fire Resistance |
What to Look For |
Notes |
|
Roofing material |
Slows flame spread and resists ignition |
Class A fire rating |
The roof covering is only one part of the fire-resistant assembly |
|
Underlayment |
Protects the roof deck beneath the roofing material |
Fire-rated synthetic underlayment |
Standard felt underlayment may not provide the same fire resistance |
|
Roof vents |
Prevent burning embers from entering the attic |
Ember-resistant vents |
Especially important in wildfire-prone areas |
|
Gutter guards |
Reduce combustible debris in gutters |
Metal gutter guards that shed leaves and pine needles |
Clean gutters further reduce fire risk |
|
Roof decking |
Supports the roofing system |
Approved roof decking for the roofing assembly |
Some Class A ratings depend on specific decking materials |
|
Flashing |
Helps protect roof penetrations |
Properly installed metal flashing |
Also improves weather resistance |
|
Chimney flashing |
Helps prevent sparks and water intrusion |
Proper flashing and chimney clearances |
Important around wood-burning fireplaces |
|
Roof maintenance |
Removes combustible debris |
Regular cleaning and inspections |
Pine needles and leaves can become fuel for embers |
|
Vegetation management |
Reduces fire exposure around the home |
Trim trees and maintain defensible space |
Especially important near forests or greenbelts |
|
Complete roof assembly |
Determines the overall fire rating |
Components tested together |
Many roofing products only achieve Class A as part of a complete assembly |
Pairing a roof material with a Class A fire rating and a fire-resistant roof assembly is an excellent way to make sure that your home is protected, especially in a wildland urban interface zone.
These are all examples of Class A fire-rated materials:
Diving into specific brands and styles can change this rating. Some materials are Class A all by themselves, while others require specific elements to be included when building the whole roof to make them meet Class A requirements.
Any of these options are great for protecting your roof, and there is a wide variety of different materials, so you can easily find something that meets your budget and aesthetic preferences.
Metal is a good choice if you have a higher budget and want something that will work well. Asphalt shingles are the most budget-friendly option. Fire-treated cedar shake will be expensive because you have to treat the shakes and get the right roof assembly, but if you really want to have actual cedar shake, it can be done.
Class A is the highest fire rating that any roofing material can get, but what does it really mean? These materials undergo rigorous testing, and when they’re awarded a Class A rating, it means that they do well in severe conditions and have the best resistance to catching fire and spreading flames.
The test simulates fire embers landing on the roof (because that’s how most fires start), and the roof must protect the deck below from catching fire,
A roofing material can also have a Class B or Class C fire rating, which means that they are not as good at resisting flames as the roof materials. These are not acceptable materials to use if you need to be cautious about fire resistance in your roof.
When you are looking at roofing materials online, they list the fire rating and other information on the website, so it is easy to quickly find this information. Make sure to distinguish between materials that reach Class A on their own and materials that need a particular roofing assembly to reach Class A status.
Creating a fire-resistant roof involves much more than just choosing a Class A roofing material. As you've learned, the entire roof assembly (including the underlayment, vents, gutter guards, flashing, and even ongoing maintenance) works together to help prevent fire from spreading.
That's why choosing the right roofing contractor is just as important as choosing the right roofing products. A knowledgeable roofer understands how each part of the roofing system contributes to your home's fire resistance and can recommend the right assembly for your home's location, building code requirements, and budget.
Read our article “Is Your Seattle Roofer Actually Good? Here’s How to Tell Before It’s Too Late” to learn how to evaluate a roofing contractor's experience, certifications, inspection process, and technical knowledge so you can confidently hire someone who will build a roof that's designed to protect your home for decades to come.