The l rating is based on the amount of air leakage through the test sample. Some examples are outlet boxes, sink drains, or conduit that leads from a back-box to the space above the ceiling. The f rating is simply a measure of the ability of the system to resist fire, but no hose stream test. Some of these products involve fairly sophisticated installation procedures that must be followed exactly if the material is expected to act as designed. You may want to use. The fth rating is a combination of all of the above. The concept of prevention is simple.
Fire barrier construction
Through penetration fire stop. One method that may be used, while not always accurate, is to look for labels on doors and frames that contain hourly ratings. Remove or limit fire hazards to prevent (or minimize the probability of) fire. The w rating is used to evaluate a system’s ability to restrict water migration in applications that demand a higher degree of water resistance. A f-rated opening shall also withstand a hose stream test.
Through-penetration firestop systems