Are Asphalt Shingles Flammable?

  It was the middle of a sweltering summer afternoon when I noticed just how much heat my roof was absorbing. I’ve always been proactive about home maintenance, but this time, a different thought crossed my mind. What if the intense heat actually posed a danger to the very shingles meant to protect my house? Could they catch fire? This question led me down a path of research into whether asphalt shingles are flammable and how they handle fire.

What Are Fire Ratings?

  Before diving into the specifics of fire ratings, let’s get clear on what fire resistance really means. It’s all about how well a material can stand up to intense heat without breaking down structurally. Think of it as the material’s ability to hold the line when faced with fire. When I first started working with roofing materials, understanding fire ratings was key in assessing safety.

  Now, when we talk about asphalt shingles, we can confidently say they are fire-resistant. Why? It all comes down to their makeup. Asphalt itself is naturally resistant to fire, which is a good start. But there’s more to it. The exposed granules on asphalt shingles, which are what you see when you look at the roof, are coated in ceramic. This coating isn’t just for looks—it’s designed to protect your roof from sparks and embers, which is crucial, especially in areas where wildfires are a risk.

  Here’s where fire ratings come into play. These ratings are like a safety scorecard for roofing materials, showing how well they can resist fire. If you live in a wildfire-prone area, having the highest fire-rated roofing material, known as Class A, is something I’d strongly recommend. These are the type of asphalt shingles you get from reputable manufacturers like PABCO Roofing Products. Class A asphalt shingles are at the top of the fire rating scale.

  But let’s not stop there. The ultimate test of whether asphalt shingles are truly fire-resistant lies in whether they meet ASTM standards . These standards are the industry’s way of ensuring that roofing materials can perform under fire conditions. So, when you see shingles with a Class A rating, and they’re UL Listed, that’s your confirmation that they meet these tough standards. That’s the kind of assurance I look for when advising on roofing options.

How Are Fire Ratings Tested?

  Understanding how fire ratings are tested can give you confidence in the roofing materials you choose, especially if you live in a fire-prone area. When I first began working with roofing, I realized just how crucial these tests are in ensuring safety. Here’s how the process works.

1. Surface Flame Spread Test:

  One of the key tests involves measuring how quickly flames spread across the surface of the roofing material. In this test, the material is exposed to a direct flame under controlled conditions, typically for 10 minutes. They observe how fast the fire travels across the surface and how much of the material burns. The slower the flame spreads, the better the fire rating. For example, Class A materials must have a flame spread index of 0 to 25, meaning they allow minimal fire spread. This test is crucial because it simulates what could happen if a spark or ember lands on your roof.

2. Intermittent Flame Exposure Test:

  In this test, the roofing material is repeatedly exposed to and then removed from a flame source. The material is exposed for 5 minutes, then allowed to cool, and this cycle is repeated multiple times. The goal here is to see how the material behaves under intermittent fire conditions, similar to what might happen during a wildfire with shifting winds. They check if the material can resist ignition and prevent fire from penetrating through to the underlying structure. A material that withstands this test without sustaining damage is more likely to receive a higher fire rating.

3. Burning Brand Test:

  This test involves placing a burning wooden brand, usually about 12 by 12 inches, on top of the roofing material to see if it will catch fire. The brand is left on the material until it burns out completely. The idea is to simulate what happens when embers or burning debris land on the roof during a fire. The test evaluates whether the roofing material can withstand the brand without igniting or letting the fire spread. For a Class A rating, the material must not ignite or allow the fire to spread beyond a certain point, typically less than 6 inches from the original position of the brand.

4. Heat Resistance and Structural Integrity Test:

  Heat resistance is another critical factor. They expose the material to extreme heat, often around 1400°F (760°C), to see if it maintains its structural integrity. This means testing whether the material can stay intact without warping, melting, or allowing fire to penetrate through it. The material’s ability to endure high temperatures without breaking down is crucial for its fire rating. Class A materials must withstand this level of heat for at least 30 minutes without structural failure.

5. Classification of Results:

  Once all these tests are done, the results are analyzed. Materials are then classified into one of three main fire ratings: Class A, B, or C. Class A offers the highest level of fire protection, meaning the material performed exceptionally well across all tests, often allowing for a maximum flame spread of only 6 feet or less. Class B provides moderate protection with a flame spread of 8 feet or less, while Class C offers basic fire resistance, with a flame spread of up to 13 feet. I always advise going for Class A materials whenever possible, especially in areas where fire risk is a concern.

  These tests are rigorous because they need to be. They ensure that the roofing material you’re considering will not only look good and last long but also keep your home safe in case of a fire. When I’m helping clients choose roofing materials, knowing these tests have been passed gives both me and the homeowner peace of mind.

  When I first started working with roofing materials, I quickly learned that not all shingles are created equal, especially when it comes to fire resistance. Asphalt shingles, like many other roofing materials, are rigorously tested to determine their ability to withstand fire. These tests are essential because they simulate real-life fire conditions, helping us understand how well a roof can protect a home during a fire.

  Class A is the highest rating available for asphalt shingles. Shingles that earn a Class A rating can withstand severe fire exposure, making them the best option for fire protection. During testing, Class A shingles must withstand a flame spread of less than 6 feet and maintain their integrity under intense heat, often up to 1400°F (760°C), for at least 30 minutes. These shingles are made with non-combustible materials or have additional fire-resistant treatments, which slow down the ignition process and prevent flames from spreading quickly. When I recommend Class A shingles, it’s because they offer the highest level of security, especially in wildfire-prone areas. Homes with Class A shingles are statistically less likely to suffer extensive damage in a fire.

  Class B shingles offer moderate fire protection, with a flame spread of up to 8 feet. These shingles are typically made from less fire-resistant materials than Class A shingles but are still treated to improve their fire resistance. Class B shingles can resist fire for a shorter period, typically up to 15 minutes, under similar testing conditions. While they are a good choice in areas with a lower risk of wildfires, I generally advise clients to consider upgrading to Class A shingles if possible, as the added protection can be invaluable.

  Class C shingles provide the most basic fire protection, with a flame spread of up to 13 feet. These shingles are designed to resist light fire exposure for about 10 minutes before they start to fail. They’re often made from organic materials that are more prone to burning. While Class C shingles might be suitable in regions with very low fire risk, I always discuss with homeowners the potential trade-offs in safety. Given that fires can be unpredictable, investing in higher-rated shingles can provide better peace of mind.

  The classification of asphalt shingles is based on tests conducted according to standards such as ASTM E108 or UL 790, which are widely recognized in the industry. These standards require the shingles to undergo various tests, including the Surface Flame Spread Test, Burning Brand Test, and others, to assess their performance under fire conditions. The results from these tests determine whether the shingles meet the criteria for Class A, B, or C ratings.

  When I consider these ratings, I think about more than just compliance. It’s about ensuring that the roof will not only look great and last long but also protect what’s inside the home when it matters most. The data from these tests help me guide my clients toward making informed decisions that could ultimately save their homes and lives in a fire event.

Key Factors in Selecting Asphalt Shingles

  When selecting asphalt shingles, especially with a focus on fire resistance, there are several key factors to consider. Each one contributes to the overall safety and effectiveness of the shingles for your home.

1. Fire Rating:

  Fire ratings are crucial. Asphalt shingles are classified into three categories based on their fire resistance: Class A, Class B, and Class C. Class A shingles offer the highest level of protection, meaning they can withstand severe fire exposure without significant damage. According to the ASTM E108 standard, Class A shingles can resist flames for at least 60 minutes in testing conditions. This level of protection is essential for areas prone to wildfires or where building codes require high fire resistance.

2. Material Composition:

  The composition of the shingles affects their fire resistance. Fiberglass asphalt shingles are generally more fire-resistant compared to organic mat shingles. Fiberglass shingles have a mineral base that provides better resistance to heat and flames. In fact, fiberglass shingles can typically withstand temperatures up to 1200°F (650°C) before degrading, while organic mat shingles might start to show signs of deterioration at lower temperatures.

3. Durability and Longevity:

  Durability goes hand-in-hand with fire resistance. High-quality shingles should offer long-lasting performance and weather resistance. For instance, architectural asphalt shingles, which are thicker and more durable than standard three-tab shingles, often come with warranties ranging from 30 to 50 years. This extended warranty indicates their ability to withstand harsh weather conditions, including high temperatures and UV radiation, which can contribute to fire safety by maintaining the integrity of the roofing material over time.

4. Local Building Codes:

  Building codes vary by region, and it’s important to ensure that the shingles meet local requirements. For example, the California Building Code (CBC) mandates that roofing materials in fire-prone areas must have a Class A rating to be compliant. Checking these regulations can help ensure that the shingles you choose are suitable for your area’s specific needs.

5. Aesthetic Appeal:

  Fire-resistant shingles come in a wide range of styles and colors. While safety is paramount, you don’t have to compromise on appearance. Many Class A rated shingles are designed to mimic the look of traditional roofing materials like wood shakes or slate, providing both beauty and protection. For example, some high-quality asphalt shingles offer a range of colors and textures that can enhance your home’s curb appeal while meeting fire safety standards.

6. Budget Considerations:

  Fire-resistant shingles are often more expensive, but they offer long-term benefits. The cost of Class A shingles can range from $90 to $120 per square (100 square feet), compared to $70 to $90 for Class B or C shingles. Investing in higher-rated shingles can be a wise decision, considering the potential cost of fire damage and the added value of long-term durability.

  In my experience, carefully considering these factors helps in selecting the best asphalt shingles for your home. It’s about finding the right balance between safety, durability, and budget, ensuring that you get a product that provides reliable fire protection and enhances your home’s overall value.

Top Recommended Fire-Resistant Asphalt Shingle Brands

  When it comes to choosing fire-resistant asphalt shingles, selecting the right brand can make a big difference. Here are some top brands to consider:

1. GAF Timberline HDZ

  GAF Timberline HDZ shingles are highly recommended for their fire resistance. They feature a Class A fire rating, the highest level, which means they offer excellent protection against fire. The technology used in these shingles improves their durability and performance.

2. Attiroof

  At Attiroof, our asphalt shingles incorporate a fiberglass base, enhancing their strength and fire resistance. These shingles are designed to perform well in extreme temperatures, from as low as -35°C to as high as 68°C, without losing their shape or integrity. Our shingles also hold a Class A fire rating, ensuring superior protection.

3. CertainTeed Landmark

  CertainTeed Landmark shingles come with a Class A fire rating. They are known for their reliability and resistance to both fire and severe weather conditions. This makes them a strong choice for many homeowners seeking dependable fire protection.

4. Owens Corning

  Owens Corning shingles are another excellent option, featuring a Class A fire rating. Their construction includes a triple layer that provides added protection against high temperatures and fire. These shingles are known for their durability and performance.

  Choosing shingles from these trusted brands ensures that you are investing in high-quality, fire-resistant materials. Always verify that the shingles meet Class A fire ratings to ensure the best protection for your home.

  In summary, when considering whether asphalt shingles are flammable, it’s important to understand that while asphalt shingles are generally fire-resistant, their level of fire resistance varies based on their fire rating. Opting for Class A asphalt shingles ensures the highest level of fire protection, offering superior safety and durability for your home.

  Ready to upgrade? Contact us today to find the best fire-resistant shingles for your home!