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Common walls multiple dwelling

northwindsbuilding

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Joined
May 5, 2017
Messages
1
Location
Macomb Twp.
I am in the preliminary stage of designing a 4 plex multiple dwelling in michigan. My question is how thick do the common walls need to be between the attached dwellings per fire code? I guess I want to know how much drywall do the common walls need on them
 
What code and edition has the ahj adopted??

Maybe at the most a listed one hour wall design
 
Somewhere around 6" to10" might be the minimum....shaftwall could get you a fairly narrow "rating", but then you nee to hold it up with walls on either side. A 2 hr common wall (4 layers) at 6"ish might work, but there are limitations as to what can be in it....
 
yu need to know the required rating, then find a listed assembly that meets that rating. UL has books and book with the different combination of materials that can be constructed to meet the required rating. one example linked here
 
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