How Do I Make Sure My Roof Is Class A Fire-Rated?

 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.

What makes a roof fire-resistant?

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:

• Underlayment: Synthetic underlayment is required for your roof to classify as fire-resistant. Felt paper underlayment is legally allowed on roofs, but it is NOT rated for fire resistance.
• Vents: Intake vents are a major risk because they can suck burning embers into the home, causing it to catch fire. To prevent this, they must meet California fire code (meaning that they DO NOT suck in burning embers). O'Hagin vents are great because they meet this standard. Most intake vents do not meet this standard, so you have to be careful about which ones you choose.
• Gutter Guards: Debris from trees (leaves and pine needles) can collect in your gutters and ignite from burning embers that fly around, creating a fire ring around your entire roof that catches the rest of your roof on fire.
• Solution: Installing gutter guards can help prevent debris from collecting in the gutter. We recommend MasterShield gutter guards because they are installed at the same slope as the roof, making it easy for debris to fall right off. Other gutter guards sit flat on the roof, so the debris collects on top of that rather than in the gutter.

Roofing Materials and Components That Improve Fire Resistance

Which roofing materials have the best fire resistance?

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:

• Metal
• Asphalt Shingles
• PVC Membrane
• Tile
• Slate
• Fire-treated Cedar Shake
• Brava

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.

What does it mean when roofing materials have a Class A fire rating?

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.

How do you choose a roofing contractor who knows how to build a fire-resistant roof?

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.