fire rated wall

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Once again, the Ul orange books say boxes must be fastened to the studs regardless of type and unless someone finds some info to the contrary it is what it is.

Roger
 
roger said:
Once again, the Ul orange books say boxes must be fastened to the studs regardless of type and unless someone finds some info to the cobtrary it is what it is.

Roger
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Thank you for that Roger, but can you reference the listing. I can't find it. I spent about an hour looking, because I am 100% on the same page as you.
 
Strathead, my modem got trashed last Friday in the storms, supposed to have a new one tomorrow I will look then, this phone sucks for trying to find things.
FWIW, it's in the first few pages of volume one of the orange books

Roger
 
roger said:
Once again, the Ul orange books say boxes must be fastened to the studs regardless of type and unless someone finds some info to the contrary it is what it is.

Roger
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So...The better option, in old work, is a rated "smart" plastic box.:happyyes:
 
mortimer said:
So...The better option, in old work, is a rated "smart" plastic box.:happyyes:
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No, you don't seem to get the gist. Just because a box is rated for a 2 hour wall doesn't alleviate it from being attached to the studs. ALL standard metal boxes are rated period. They don't have to be stamped. Plastic boxes are not rated, so the they have to be stamped.
 
mortimer said:
So...The better option, in old work, is a rated "smart" plastic box.:happyyes:
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Finding a plastic box manufacturer that list their old work boxes for use in rated walls will be the problem, I know Carlon doesn't.

With that said, UL assemblies have specific requirements down to fire stopping materials, you can not just smear some fire caulk around a conduit and say it's good to go, it has to be installed per the particular assembly.

Roger
 
Finally found this here:http://database.ul.com/cgi-bin/XYV/...rent_id=1073984818&sequence=1#SectionIIIitem6


6. Metallic Electrical Outlet Boxes
Metallic outlet boxes with metallic or nonmetallic cover plates may be used in floor-ceiling and roof-ceiling assemblies with ratings not exceeding 2 hours. These assemblies should have gypsum board membranes. The metallic outlet boxes should be securely fastened to the joists and the opening in the gypsum board facing should be cut so that the clearance between the box and the gypsum board does not exceed 1/8 in. The surface area of individual boxes should not exceed 16 sq. in. The aggregate surface area of the boxes should not exceed 100 sq. in. per 100 sq. ft of ceiling surface.
 
FWIW, here is the wording for metallic boxes.

WALL AND PARTITION ASSEMBLIES

Metallic Eletrical Outlet Boxes

Listed single and double gang metallic outlet and switch boxes with metallic or nonmetalliccover plates may be used in bearing and nonbearing wood stud and steel stud walls with ratings not exceeding 2h. These walls shall have gypsum wallboard facings similar to those shown in Design Nos. U301,U411, and U425. The metallic outlet or switch boxes shall be securely fastened to the studs and the opening in the wallboard facing shall be cut so that the clearance between the box and the wallboard does not exceed 1/8 in. The surface area of individual metallic outlet or switch boxes shall not exceed 16 sq in. The aggregate surface area of the boxes shall not exceed 100 sq in per 100 sq ft of wall surface.
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Roger
 
Adamjamma said:
But... is there any requirement for a non metallic box that has a fire rating to be attached to the studs? Just asking the question because a Cement Wall has no studs... ;)
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It also has no sheetrock, paneling, tile, etc... used as the rated membrane that would be compromised, the concrete itself would be the barrier.

Roger
 
sometimes it has sheet rock and sometimes it has tiles and sometimes it has plaster... but the main fabric is cement... when sheet rock is added it is usually dot and dab rather than any studs...lol... because the wood rots quicker trhan dot and dab method gives problems...

Which makes me wish those plastic boxes for CIF jobs were not so expensive... something like them set up for PVC conduit.. that would be nice for us in the concrete world..lol..
 
Adamjamma said:
sometimes it has sheet rock and sometimes it has tiles and sometimes it has plaster...
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And as I said, those do not contribute to the rating when concrete is the rating material.

Go to this page and you can see the hundreds (probably thousands) of different assemblies.

Roger
 
Adamjamma said:
sometimes it has sheet rock and sometimes it has tiles and sometimes it has plaster... but the main fabric is cement... when sheet rock is added it is usually dot and dab rather than any studs...lol... because the wood rots quicker trhan dot and dab method gives problems...

Which makes me wish those plastic boxes for CIF jobs were not so expensive... something like them set up for PVC conduit.. that would be nice for us in the concrete world..lol..
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You either don't understand fire rated assemblies or you are being a jerk. Perhaps you should learn what a fire rated assembly is. This ENTIRE discussion has been about boxes in a fire rated wall assembly that consistes of studs and sheetrock. Various types of concrete and block walls are also fire rated assemblies, but the UL assembly is a different number with different requirements.
 
Strathead said:
You either don't understand fire rated assemblies or you are being a jerk. Perhaps you should learn what a fire rated assembly is. This ENTIRE discussion has been about boxes in a fire rated wall assembly that consistes of studs and sheetrock. Various types of concrete and block walls are also fire rated assemblies, but the UL assembly is a different number with different requirements.
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I'm pretty sure he doesn't understand what they are.

Roger
 
I am fen a jerk but in this case I was looking for knowledge. And someone led me to a set of pages where I could receive it. Thus, I am smarter tonight than I was last night, even if I still do not understand all of it.
i still do not understand why a box that installs in wallboard and requires no attachment to a stud plus has a one hour fire rating according to the sheets on it is not considered to be fire rated. But, in the future, should I ever need to do a fire rated assembly, I will know to use metal conduit and metal boxes attached with metal screws to studs to simply not need to stress myself, along with using the fire rated pads in some places to seal my openings thus slowing the transfer of fire. If it were not for certain people on here, i would not know any of that, nor would I realize just how little I know about it...
 
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