Overview of ASTM E84: What You Need to Know About Fire Ratings and CeDUR Roofing Products

The last thing any homeowner wants is a roof that easily catches fire. Not only would it damage your roof but it would also cost you expensive repairs down the line.

But this primarily occurs when a home doesn’t have effective fire-resistant roofing installed.

How do you know if your roof is prepared for fire safety? Make sure it has ASTM E84 roofing installed.

What is ASTM E84?

ASTM E84 is a standard test method used to evaluate the surface burning characteristics of building materials.

Although commonly known as the “Steiner Tunnel Test,” the ASTM E84 test measures two elements of building material fires:

1. How quickly flames spread across the surface of a material

2. The amount of smoke it produces when ignited. 

The purpose of the test is to provide a clear indication of how a building material will behave in the event of a fire—and assess the safety of the material in terms of rapid fire spread. Essentially, this test measures surface burning characteristics like smoke development and flame spread.

How Does ASTM E84 Testing Work?

ASTM E84 testing involves placing a sample of the material in a tunnel-like chamber, where it is subjected to a controlled flame for 10 minutes. As the flame travels across the sample, measurements are taken to determine two main factors: The ASTM E84 Flame Spread Index (FSI) and Smoke Developed Index (SDI).

The Flame Spread Index

The FSI helps determine and label how quickly flames spread along a material's surface. At the end of the time period, the material is assigned a number 0-200—with the highest numbers indicating the material will spread the flame the quickest.

Once this is finished, each material is then given an A,B, or C fire rating:

• Class A (0-25): These materials have excellent fire resistance and minimal flame spread. This is the highest rating and the best choice for roofing.

• Class B (26-75): Materials with this classification have moderate flame resistance and an increased level of flame spread.

• Class C (76-200): This is the classification for materials with the highest flame spread and least resistance to fire.

Smoke Developed Index

Equally important is the SDI, which measures the amount of smoke emitted as a material burns. Another way to think of it is that the materials with SDI are the same materials that contribute to visibility issues during fires, posing a significant threat to those who are inside a building during fires.

SDI scores range from 0–450, with lower scores indicating less smoke production and higher scores indicating more.

Ideally, you may want to consider a roofing material with a low SDI so it produces less smoke and a high FSI so that flames spread slower.

Why is ASTM E84 Testing Important?

While there are various tests available to assess the fire resistance of building materials, ASTM E84 remains a widely recognized and, arguably, the most trusted. Here’s why:

Fire safety should always be a top priority for homeowners and property owners, especially if they live in areas where wildfires are likely.

The ASTM E84 fire rating provides clear, understandable, and fair ratings and classifications that homeowners and builders can both use to identify the best building materials for properties in these areas.

In other words, ASTM E84 testing gives you—the property owner—the confidence that your roofing material can help prevent fire from spreading rapidly across your roof, which could possibly save your life or even your property.

Consider CeDUR Fire Resistant Synthetic Roofing Products

Your roof is the first line of defense against wildfires and a CeDUR synthetic roof is one of the most fire-resistant roofing products available for purchase. CeDUR synthetic shakes are Class A Fire Rated and no special fire-resistant underlayment is required during installation to achieve the Class A Fire Rated roofing system.

In the event of a wildfire, roofs are the most vulnerable part of a home because they present a large expanse where burning debris and embers may land. Flames spread from roof to roof, with embers from the fire being a major cause of traveling fire damage. Sparks and ignited debris can be lifted and carried by convection currents up to a half-mile from a fire.

Using our proprietary technology, CeDUR synthetic shakes can extinguish flame spread and will not allow a flame to propagate on the surface of the product. CeDUR products are stand-alone Class A Fire Rated without the need of a special fire-resistant underlayment during installation. This fire-resistant technology is patented and proprietary to CeDUR.

CeDUR Synthetic Roofing Products perfectly replicate the desirable wood shake look while providing extreme fire resistance. The look of CeDUR is so similar to that of heavy hand-split natural cedar wood shakes, that it is approved and trusted in mountain communities and builder developments for it’s consistency in appearance to natural wood shakes and its stand alone Class A fire resistance. Implementing a synthetic roofing product that can extinguish flame spread in the event of a fire has the potential to save properties and save lives.

CeDUR Shiloh

Shiloh brings the timeless elegance of weathered wood with the strength of modern fire-resistant technology. Its rich, rustic tones provide a classic aesthetic while offering premium durability and protection.

CeDUR Live Oak

Live Oak captures the warm, inviting hues of natural oak while meeting the highest fire safety standards. It’s a flexible color option that improves home appeal by blending durability and craftsmanship.

CeDUR Walden

Walden offers deep, earthy tones that mimic aged cedar—perfect for homeowners seeking a natural wood look—without the fire risk. By having an ASTM E84 Class A fire rating, Walden delivers both beauty and security in one.

Consider CeDUR’s Fire Resistant Roofing Materials

Now that you know more about ASTM E84 testing and how ASTM e84 ratings are determined, it’s time for you to use that knowledge to find the best roofing material for your home or property.

Here at CeDUR, we celebrate the fact that our products are stand alone Class A fire rated and offer increased levels of fire protection for both residential and commercial buildings.

If you are interested in learning more about CeDUR’s Class A fire rating, contact us today!

But if you want to explore more about our products, you can always view our additional resources, check out our benefits, or request a sample