What Do Fire Resistance Ratings Really Mean?

At first glance, most contemporary building materials look similar. They look efficient and attractive, almost perfect for your construction needs.

However, there’s another factor you need to consider when choosing materials: safety, specifically fire safety. Materials like glass can bring style and sophistication to your space, but nowadays, it’s more than just good appearances.

Modern glass technology is aesthetically pleasing and has functional safety features. This high-performance safety material is known as fire rated glass. If you’re looking to install fire rated glass in your building, things may get confusing since there are several technical aspects you should consider. States have different code requirements, and some areas need more fire resistance than others.

Fire rated glass comes with fire resistance ratings. To get the right materials for your needs, we’ll discuss in layman’s terms what fire resistance ratings are and what they mean.

What is a Fire Resistance Rating?

Construction materials meant to withstand a fire emergency undergo fire tests. These tests evaluate the materials’ fire resistance performance for regulated use in buildings. A nationally recognized testing laboratory (NRTL) must conduct these tests. If the product passes, then it’s given a fire resistance rating.

Fire resistance ratings allow designers, architects, and contractors to conveniently classify different materials based on performance rankings. Using these ratings, you can compare and choose materials for specific projects.

The rating systems use a measure of time, typically in minutes. Under high temperatures, how long will these materials resist fire? It can be 20 minutes or 4 hours, depending on its fire resistance rating. You should know that these ratings only mean that the product was lab-tested to a certain minute rating; it doesn’t equal code compliance.

The International Building Code (IBC) has required test procedures that apply to fire rated glass products. If you plan to use fire rated glass on floors, windows, walls, or doors, you need to be aware of the testing standards for these applications.

Fire Protection Ratings vs. Fire Resistance Ratings

Wall, floor, and ceiling assemblies have fire resistance ratings. They are tested to ASTM E119 or UL 263, in which the temperature of the assemblies shouldn’t rise to more than 250°F on the non-fire side of the wall or floor.

Fire resistance ratings cover the building structure, but what about the building’s openings? Door and window openings have fire protection ratings, as well. They are tested to NFPA 252 and NFPA 257.

Aside from where it’s applied, the difference between these two ratings is the performance criteria.

ASTM E119-tested products limit the passage of dangerous radiant heat on the non-fire side, allowing for safe egress. Products with fire resistant ratings should also prove that there is no passage of gases or flame.

Meanwhile, materials with fire protection ratings cannot limit the radiant heat transferred to the non-fire side.

According to Section 716 of the 2018 IBC, all fire rated glazing assemblies should be labeled whether they’re fire resistance rated or fire protection rated. On the IBC Table 716.1 (1), assemblies with a “W” or “FC” marking are considered to have fire resistance rated glazing. If the markings are “OH” or “D” they are fire protection rated. Doors marked with a “T” indicate that they meet additional temperature rise requirements.

Key Points for Evaluating Fire Resistance Ratings

When assessing glass products’ fire resistance ratings, performance testing should be considered. It would be best if you didn’t rely on descriptions like “thick” or “thin” or the fire endurance or minute ratings (20, 45, 60, 90, or 120 minutes). These aspects aren’t enough to tell you if the fire rated glazing meets the application requirements.

Test standards must be your basis when selecting glass products with fire resistance ratings. Here’s a quick rundown of testing standards for fire-resistant products.

Fire wall assemblies

• Tested to ASTM E119 or UL 263
• Must remain intact after undergoing the hose stream, fire endurance, and radiant heat tests
• Must keep the temperature on the non-fire side below 250°F

Fire floor assemblies

• Tested to ASTM E119 or UL 263
• Must remain intact after applying a load (typically 100 psf) during the fire endurance and radiant heat tests
• Must keep the temperature on the non-fire side below 250°F

Find the Ideal Fire Resistant Products for Your Needs

If you’ve just started working with fire rated products, fire resistant ratings can be a bit challenging to navigate. They can be easily confused with fire protection ratings, however, as you get to know what fire resistant ratings are, you’ll be able to distinguish which products will suit your needs.

You don’t have to compromise aesthetics and sustainability when applying fire rated materials. With SAFTI FIRST, you can improve your building’s safety while maintaining the style and sophistication of the space. For over 40 years, SAFTI FIRST has been the leading manufacturer of USA-made fire-rated solutions. Contact us today to learn more about how fire-rated solutions can merge safety and aesthetics.