Don’t Forget About Firestopping

When most people hear the phrase "fire prevention," sprinklers, smoke detection and fire alarms spring readily to mind. While such active fire prevention measures are certainly necessary in any building—and have enjoyed a long history of success—many in the industry don't realize it's only half of the real fire-protection picture.

By Geoff Weisenberger, Production/Web Editor February 1, 2003

When most people hear the phrase “fire prevention,” sprinklers, smoke detection and fire alarms spring readily to mind. While such active fire prevention measures are certainly necessary in any building—and have enjoyed a long history of success—many in the industry don’t realize it’s only half of the real fire-protection picture.

According to Phil Zanghi, firestopping technical service manager for Grace Construction, which manufactures fireproofing and firestopping products, passive fire-protection measures get short shrift.

“Code people are very big on sprinklers, and they have basically reduced the amount of [required] firestopping and fireproofing in areas where there are sprinklers, which is kind of absurd in cases where sprinklers fail,” says Zanghi.

Compartmentalizing confusion

The purpose of firestopping, of course, is to prevent flames, gases and smoke from passing through openings created for wiring, piping, joints and other gaps in walls and flooring. In other words, it’s the act of containing a fire to the area in which it starts in order to provide more time for occupants to exit a building.

Part of the problem, according to Randolph Tucker, a senior vice president and product engineer with the Houston office of fire and security consulting firm Rolf Jensen and Associates, Inc., is that many designers often don’t understand how to put a firestopping plan together. “Unfortunately, I’m not sure that many people who are dealing with [firestopping]—outside of the fire protection consultants and manufacturers—really understand the differences between these assemblies.”

Too often, he adds, designers simply call the manufacturer they deal with most often.

For the record, firestopping products include intumescent and elastomeric products, sealants, mortar, putty, firestop bags, sleeves and caulks—materials that expand, encase and seal.

The problem, however, goes beyond the design community, according to Leon Bablouzian, Grace’s Global Product Group marketing manager, Fire Protection. Installers and inspectors, he says, don’t fully understand the importance of firestopping and often don’t know how to properly implement it.

A big problem, specifically, he says, is that many installers and inspectors almost always misinterpret the meaning of the ASTM International—formerly the American Society for Testing and Materials—F Rating, which indicates the time it takes for flame to burn through to the unexposed side of a firestop assembly. For example, a firestopping system F Rating of two hours means that it should take two hours for a fire to burn through. The issue, Zanghi explains, is that many think of the F Rating on a product basis instead of a system basis. But all of a system’s components have to work together to achieve a specific F Rating.

For example, a simple firestopping system might involve a joint stuffed with mineral wool, but also sprayed with a sealant. The wool stops the heat while the sealant prevents smoke penetration. The combination of both elements is what produces the F rating.

Customization is key

Another problem that Zanghi points out is that too many installers want to use the same firestopping products and systems for every application, a mistake that could prove both costly and deadly.

Tucker suggests that the best thing to do when exploring firestopping systems is to consult Underwriters Laboratories’ directory and locate one that best meets a project’s conditions and rating requirements.

“Unless you have a test specific to your condition, there’s no assurance that you’re doing it correctly,” he says. “If I’m bidding a job and I know all of the different types of openings, I should have a UL system design prepared that I plan to use for all of the openings before I even go out there with anything in hand,” says Tucker.

For more information, Grace’s web site has more than 300 drawings of firestopping systems tested to UL and ASTM standards. Visit .

Firestopping tips:

Don’t leave firestopping out of your fire protection plan.

Think “system,” not “product.”

Choose or develop a firestopping plan specific to your project.