UL 1479

1.1 These requirements cover through-penetration firestops of various materials and construction that are intended for use in openings in fire resistive wall or floor-ceiling assemblies, or both.

1.2 The method of testing through-penetration firestops as specified by these requirements consists of exposure of test samples to a fire of standard time and temperature and to an application of a hose stream. Ratings are then established on the basis of:

1. The length of time the firestop resists fire before the first development of through openings or flaming on the unexposed surface,

2. Acceptable limitation of thermal transmission, and

3. Acceptable performance under the application of the hose stream.

The method of testing also includes air leakage tests to determine the rate of air leakage through test samples resulting from a specified air pressure difference applied across the surface of the test samples. Three ratings are established for each test sample; an F rating based on flame occurrence on the unexposed side of the test sample and acceptable hose stream performance, a T rating based on temperature rise and flame occurrence on the unexposed side of the test sample and acceptable hose stream performance, and an L rating based on the amount of air leakage through the test sample.

1.3 The method of testing through-penetration firestop systems containing piping systems for vented (drain, waste or vent) systems and closed (process or supply) systems is differentiated by the capping or non-capping of the piping systems on the unexposed side of the test assembly as described in 4.1.2.

1.4 Tests conducted in accordance with these requirements are intended to demonstrate the performance of through-penetration firestops during exposure to fire, but are not intended to determine acceptability of firestops for use after exposure to fire. These requirements do not cover the ampacity of conductors encased in through-penetration firestop materials.

1.5 The results obtained from the air leakage tests are expressed in cubic feet per minute (cubic meter per second) per square foot (square meter) of opening. The results are intended to develop data to assist authorities having jurisdiction, and others, in determining the acceptability of through-penetration firestops with reference to the control of air movement through the assembly.

1.6 These requirements do not cover devices that penetrate fire resistive floors and walls but terminate on the opposite side, as, for example, an outlet box and fitting.