Can you Fire Rate a floating wall?
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| Posted in Construction Techniques on
I have to have floating walls for the interior of a single story building due to the fact that the soil under the slab is compacted fill. The problem I have now, is making the corridor walls 1 hour fire rated. I’m using wood studs and my gap for vertical movement is 2″, just under the top stud. Colorado building dept. wants a “Listed” wall construction, and don’t seem to want my detail showing type ‘X’ sheet rock and fire sealant. Hilti doesn’t have one for this wall construction. Is there such a UL listing for a fire rated floating wall?
Replies
What they are referring to as “listed” means you have to provide and install according to a UL listed assembly. They will not approve an assembly thought up by you as the UL listings have gone through multiple testing and have been found to work (not saying yours won’t work). You will need to provide them with the UL listing ID number and probably a detailed drawing of the listing as well. If you go to ul.com you can find more info. I usually like to go to the major drywall manufacturers websites for Fire rated assemblies as they have detailed drawings that you can thumb through easily to match what you need.
For your floating wall. Why does it need to float? If you have backfill compacted well enough and have solid concrete floors it should be fine. Have you noticed your slab heaving or settling a lot?
How about a deep metal track to allow the movement as well as provide the seal. Not in Colorado but we’ve framed this type of movement framing commercially with all metal studs.
Your application maybe a single wood plate allowed to float in a deep throat channel up top.
Times change, my years of commercial framing are several yrs gone, but maybe if your lucky, might apply.
If you cant find a UL assembly you can often get an Engineering judgement ( a slight deviation form the UL listed assembly) that the building department will accept. The fireproofing/firestopping manufacturers will often give you the judgement for free.