Rated Walls

[ssn61]

I am working on bathrooms renovation at an existing assisted living building in Texas. We want to route the exhaust duct through the outside walls. The question is whether NBC and NFPA codes allow that. Are perimeter walls in such buildings fire rated? If they are, then can we penetrate them with bathroom exhaust ducts?

 

[Dougt115]

I would think that this is a question for your local city building code department.

I have seen them through walls and interior walls but never up through exterior walls.

How will you handle the roof or will you switch to and interior wall at a second story?

 

[dbill74]

Generally speaking, no, exterior walls are not rated unless it is immediately adjacent to another building (common in a downtown area where building are just a few feet from each other), in which case it would need to be (check your codes or with building officials for a cut-off distance).
Unless the exisitng bathroom exhaust system is tied into an energy recovery unit or multiple rooms connected to a common EF, there is no issue with routing the bathroom exhaust to an exterior wall.

Even if the exterior wall is rated, you would be allowed to terminate in such a wall so long as the termination is rated.