fire code: 1 or 2 layers of drywall
HI- I live in a 45 unit condo (5 stories) with sprinklers. I am confused about the codes concerning the thickness of the walls between residences. It seems that two layers of 5/8 drywall on each side is code and we have only one layer. I suspect that the sprinklers may have an impact on…
HI-
I live in a 45 unit condo (5 stories) with sprinklers. I am confused about the codes concerning the thickness of the walls between residences. It seems that two layers of 5/8 drywall on each side is code and we have only one layer. I suspect that the sprinklers may have an impact on this ? We have had issues with our sponsor, so I don’t necessarily assume everything was done right. Initially, it was the large amount of noise travelling between units that drew my attention. Oddly (or not) it is 2 layers thick in the sleeping loft area. Any help would be appreciated.
Anon 5:19pm. I love it, the declarative “impossible” combined with the escape clause “of course I could be wrong”. Thanks to anon 9:44pm, the surrounding issues are becoming clearer. A few more facts that might help illuminate the question. I’m pretty sure our building is “non-combustible” as it is cast concrete. All the existing drywall is one layer of 5/8″ fire rated except for in the bedroom areas (probably added for sound control ? ) My concerns were prompted by two reputable project-managers (different companies) of large scale building renovations mentioning the two layer drywall issue. Given how many condos they have converted/rehabbed, I don’t think they were making anything up, though the specifics might not apply to my building. thanks in advance
It depends on the type of drywall installed. You can have one layer on each side of the stud and still have a 1-hour rating, as long as you’re using a fire-rated gypsum board (aka drywall) like Type X, along with batt insulation. Plain gypsum board will not give you a fire-rated wall. If a 2-hour wall is required, usually you would need 2 layers (1/2″ min) on each side of a 3-5/8″ stud. Sprinklers do allow some leeway in terms of fire rating, but the requirements also depend on the construction of the entire buildling (ie, combustible vs. non-combustible construction).
Impossible. There’s got to be one layer of sheetrock on each side of the dividing walls.
There’s no law that states you need two layers on BOTH sides that I’ve ever heard of in an apartment building of any kind.
I believe new woodframe houses that abutt each other do require two layers of sheetrock, but that’s another story. . .
of course I could be wrong