How should membrane penetrations be treated within a firestop system?

Membrane penetrations must be treated carefully within a firestop system to ensure that they provide the intended fire resistance. The correct approach is to firestop them as half of a symmetrical through-penetration system. This is essential because membrane penetrations can compromise the fire-resistance rating of a wall or floor assembly. To maintain the integrity of the fire-rated barrier, both sides of the penetration should be equipped with firestop systems that are compliant with the appropriate regulations and industry standards.

This method ensures that the firestop material adequately seals the penetrations, preventing the passage of flames, smoke, and hot gases, which can contribute to the spread of a fire. By treating the penetration in this manner, it provides a balanced approach to fire protection and maintains the performance of the fire-resistive assemblies overall.

Other choices present inadequate approaches. Stating that firestopping is not necessary overlooks the critical role that seals play in fire safety. Only firestopping one side of the penetration fails to recognize how heat and flames can travel through the openings, potentially accessing the other side that is left unprotected. Isolating the penetration from the structure does not address the need for containment of smoke and fire, as it doesn't provide the necessary fire resistance and continuity