Back to Basics - What is the F-Rating

The F-Rating is the duration measured in hours that an installed firestop system will resist the passage of fire. A firestop system’s F-rating results from fire testing a given configuration to an appropriate test standard, with a resulting listing issued by a Nationally Recognized Third-party Testing Laboratory.  

In the United States you will commonly see the below standards referenced when determining F-Ratings: 

• ASTM E814/UL1479 for Penetrations
• ASTM E1966/UL2079 for Construction Joints 
• ASTM E2307 for Perimeter Fire Barriers
• ASTM E119/UL723 for Assemblies such as walls, floors, and ceilings

Each of the above-listed test standards utilized the same time temperature curve ensuring consistent fire exposure across methods, while including additional criteria specific to the condition being evaluated. These four standards are the basis determining firestop systems F-Ratings and are referenced in US Building Codes as required when determining what firestop systems are acceptable for use. 

By STI Engineering Services