I have a 14x8 rectangular duct no damper penetrating a 1hr rated hallway. The room that the duct is coming from has a ceiling below the duct, so in other word the duct is above a 1hr rated ceiling and that ceilings drywall is not installed yet. Can the hallway side only be fire stopped or do both sides need to be fire stopped. Is there a one side fire stop that will suffice. the wall is 5/8 gypsum with wood studs 1 hr fire rated wall. The duct is currently wrapped with 5/8 drywall around the duct between the wood and duct.
The other issue is that there is no room for fire angle around duct due to other trades crowding the duct. sprinkler lines can't be moved. moving the duct is not possible because it takes up the entire ceiling joist cavity.
is there a solution?
Hi Neal - in general, when you are breaking the fire-resistance rating of an assembly, it needs to be restored with the appropriate firestop solution. This will be subject to AHJ approval. I would recommend a solution like W-L-7096 where the duct penetrates the gypsum wall assembly. If this system does not work, please submit an engineering judgment request using the information below.
Hilti is proud to announce the launch of our engineering website, the HILTI CONSTRUCTION PLATFORM (HCP). This platform will be the home for all of your Fire Protection Engineering needs, including Engineering Judgment requests. You can find more information on how to access this new platform here: https://www.hilti.com/ej (US) or https://www.hilti.ca/ej (Canada.)
Regards,
Nate Crawford, Lead FPE
further... there is no room for fire angle on the hallway side. and no feasible way to board above the ceiling with many other trades penetrating in that same area.
really need a one side firestop solution in the hallway