Penetrations made in a smoke barrier require what with the approved firestop system?

When it comes to penetrations made in a smoke barrier, the approved firestop system must have an L rating. This L rating indicates the system's ability to limit the passage of smoke and other gases through the barrier. Smoke barriers are critical in preventing the spread of smoke during a fire, and maintaining their integrity is essential for building safety.

An L rating is specifically associated with the system's performance concerning smoke leakage. It demonstrates that the firestop will effectively prevent smoke from passing through the barrier at any penetrations, which is particularly important in maintaining safe evacuation routes and protecting occupants.

The other options do not align with the requirements for smoke barriers. A simple rating does not address the specific need for controlling smoke passage. A double rating is not typically a recognized term in this context. No rating would imply that the system does not meet any performance criteria, which would be inadequate for safety standards required in building codes regarding smoke barriers.