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#188072 - 07/20/09 07:19 PM Common wall resi boxes
derater Offline

Registered: 03/30/02
Posts: 182
I'm roughing in a row of townhomes. The adjoining walls are separate; 2- 2x4 walls. Is there any special requirement for the device boxes on these walls p/2005 NEC? Thanks.

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#188074 - 07/20/09 08:13 PM Re: Common wall resi boxes [Re: derater]
sparkyinak Offline

Registered: 07/08/07
Posts: 1288
Loc: Alaska
That will be in the local building code requirements. The IBC for example requires a minimum of 24" or solid fire blocking i.e., framings studs.
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#188077 - 07/20/09 08:43 PM Re: Common wall resi boxes [Re: sparkyinak]
HotLine1 Offline


Registered: 04/03/02
Posts: 6792
Loc: Brick, NJ USA

There's a lot of info that you may need:

Is sheetrock going in the cavity between the two 2x4 walls? How about core wall board? It would have to go thru continuous. IF that's the case, you are in regular walls, as long as you don't penetrate thru.

IF there is nothing between the two walls:
Openings on both sides of fire rated wall must be 24" apart. Hilti makes a 'putty pad' (firestoping) that can be wrapped around boxes that are closer but it's $$$

This applies to ALL openings, electric, phone, cable, HVAC, etc.

Also, be careful for a rated ceiling with penetrations.

Your best bet is to check with the Building Inspector before you start to save what could be a lot of grief.


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