Expert: Dan Griffin - 7/18/2008

Question
My partner and I are building several firewalls in an office, we are having trouble determining what the code is...can we use two 7 foot sections of steel studs (easier to find and less expensive) or do we have to use the 17 footers, which seem impossible to find?  (Hillsborough County Florida)

Answer
Taryn, I'm sorry, I have absolutely no idea what you are talking about.  I guess you mean a fire rated assembly.  There are many rated assemblies that have been  UL tested.  Any given rated assembly is only usable exactly as drawn/tested.  This rated assembly will be specific to gauge of steel framing, number of layers and type of drywall used, fastener schedule, etc.

I am not familiar with any drywall or metal stud products available in a 7 foot increment unless special ordered, for that matter, the same is true at 17 feet.  A good commercial drywall supplier should be able to help you with a UL rated assembly, based on testing performed through the gyp supplier be it Goldbond, USG, etc.  The assebly will be quite specific about location and number of fasteners holding the framing and sealant at bottom, sides, and top.  Most assemblies need to be fire taped, fire caulked at bottom and sides, rock wool with Firedam spray or similar at the top.  This may not be contract required to be performed by the drywall contractor, most often performed by general or specialty contractor.