August 30, 2004—Underwriters Laboratories, Inc. (UL) now offers a new service to evaluate and rate the watertightness of firestop products and systems.
UL designed its W Rating to assist architects, contractors and jurisdictional authorities in determining the effectiveness of firestop material in restricting the flow of water via through-penetrations in ceilings, floors and walls, which can result from exposure to the elements during construction and from other sources after occupancy.
“Water damage and mold-friendly moisture associated with through-penetrations can be costly problems for the construction industry,” said Dan Kaiser, a staff engineer with UL’s Fire Protection Division. “Prevention is the best way to address these problems, and we believe that the optional W Rating is a step in the right direction to help the construction industry address the issue.”
The W Rating consists of three classes. Class 1-rated firestops have been shown to resist up to three feet of water pressure; Class 2-rated products have been shown to resist up to 20 feet of water pressure; and Class 3-rated products have been shown to resist up to 50 feet of water pressure.
The new W Rating joins the family of required and optional ratings UL currently offers for firestop products:
- F Rating (required) for the passage of fire
- T Rating (required) for temperature and fire
- L Rating (optional) for air leakage of smoke
For more information on the firestop W Rating, contact Monica Keeler at 847/664-2308.
