Interpretation #7410

Original Request

Code Version: 2010
Code: BUILDING
Code Description: Building
Chapter: 7
Section: 710 and 713
Topic: Smoke Barrier in Type VA

Question

Is it the intent of section 710.4 in a Type VA building, constructed of wooden roof trusses that are part of a one-hour rated ceiling roof assembly, to permit a one-hour fire rated smoke barrier to intersect the wooden roof truss at a right angle so that the wooden roof truss penetrates the smoke barrier as the smoke barrier tracks through the one-hour fire rated ceiling assembly to the roof deck above?

Answer Published 10/21/2014 at 2:29 PM

No. In type VA the smoke barrier must be supported by a
rated assembly. It would stop at the bottom of the rated
roof/ceiling assembly.

Commentary

If the application has been tested in the configuration described, it will have a design number and specifics for the construction. The penetrations contemplated by the code are pipes, tubes, conduit and the like. In this case, the penetration is by a structural member. The smoke barrier is required to be supported by construction with the same fire resistance rating as the smoke barrier.