I removed the cover plates for several of the GFI wall outlets and wall switches over a friend's house (built 1993). I was surprised that the fronts of the receptacle boxes were about 1/4 inch BEHIND the inside of the wallboard, leaving a uniform air gap of 1/4 inch on all four sides. Is this allowed by code?
Some DIY books say to mount the boxes so their fronts are flush with the finished side of the wallboard.
Home Depot (and others) sell plastic box extenders that you can easily add to each box to bring it out flush with the wall. They come in various thicknesses -- 1/4", 3/8", etc.
Here's a link:
Hi, It can happen. Use insulating foam pad under the face plate.
I just realized that you wrote that the fronts of the receptacle boxes are
1/4 inch BEHIND the back of the wallboard.In that case (if it is 1/2 inch wallboard), you will need a 3/4 inch plastic box extender to fill the gap and bring the box out flush with the wall surface.
*I think that the current code calls for the electrical box to be no more than 1/8" set back from the front face of the drywall. In 1993 it may have been 1/4". Of course in a perfect world they would all be flush. They do make adjustable boxes, but they are more expensive than a standard nail-on plastic box.
They should be installed flush to the outside of the drywall. But if you're going to err, it's better they be slightly short of flush. A cover will then fit and there is no issue. If you have the box sticking out beyond the drywall, at some point the cover plate will not fit flush to the wall.
If I understand what you have described correctly, it's definitely weird to have the box 1/4" short of the backside of the drywall. Not sure about the code issue, but one would think one purpose of the box is to keep the wire connection points enclosed within approved boxes for fire protection. Having that big gap would seem to partially defeat that objective.
I should have mentioned that the switches and outlets are flush with the finished wall. The ears on the straps rest against the finished side of the wall, and the long screws supplied with them secure them to the box. So from inside the room, everything looks beautiful. It's just the distance from the front of the wall to the front of the box is about
3/4" (1/2 inch wallboard + 1/4 inch setback). There is really no need for me to use extenders.*For 3/4" you need the extenders. It is odd that so many switch and outlet boxes would be so far off from the finished wall surface. Maybe the wall was built out a little after the electrician finished the rough-in. Maybe a previous owner built the wall out a little.
Other than fire code (most places), as I understand it. No air gaps between the device enclosure and burnable material, ie the inside of the stud bay. And even if the outlets are sitting firm now, outlets used for vacuums and such take a lot of abuse from lateral motion. Those ears can easily dig notches in the drywall.
Not saying it is a big risk, mind you. I have seen outlets that have been in place for decades like that (including this house). But the plastic extenders are cheap, and often can be slipped over the device without even disconnecting it.
As John Grabowski said, they should be set back no more than 1/4" from the front face of the sheet-rock. The purpose for the code, and the reason why you should use box extenders, would be to prevent hot molten sparks from dropping inside the wall in the event of a short circuit within the box.
Maybe a Rube set the boxes flush with the studs
Or nail-on steel box..
Often the electrician does not know what drywall is being installed. If he sets the box for 1/2" and 5/8" is installed you have a gap. If he assumes 5/8 and 1/2" is installed, the plates sit proud and the whole job looks lioke crap - - - - -.
I read you as the box being 1/4 inch from the SURFACE of the drywall
- not the back of the drywall. DEFINITEWLY not code. Get approved box extenders and install as per instructions.
Someone did NOT know what they were doing - interesting to know what ELSE they screwed up - - -.
Or mabee the previous owner did the job himself - possibly living in the building without having it totally finished, so he installed the boxes so plates were flush WITHOUT wallboard (particularly common in basements)
I had a friend, the idiot I wrote about who wouldn't take his second-string girlfriend and her daughter to the hospital, if I hadn't owned the car, and he did his own wiring of the factory loft he bought conversion to residential co-op. This was in so-ho before he moved to westchester.
He put some of hte boxes in flush with the 2x4's or even below that and the sheetrock guys were hired and did their job. They probably cut holes for the boxes, but they always do that, right? Oh, in one case he had put the wall plate on and they left it, covered the edges, and one had to stick his finger almost an inch into the hole to get to the toggle.
Andy
Modern boxes have little tabs that you use to position them on the side of the framing stud you are nailingthem to. It results in about
3/8" sticking out. The box is supposed to protrude into the wallboard.
Not likely. This townhouse is part of a complex of several hundred townhouses in the development.
Excellent consideration. But where would the sparks come from? The only things attached to the boxes are switches and duplex outlets, with the ones in the kitchen being GFI outlets.
Those were my exact concerns. I'll have to look closer next time, to see if any of the boxes also contain a bunch of wire nut connections, because the box also serves as a junction to other boxes. If so, the nuts could become lose and cause problems.
I think there is a problem there. My info has always been for the box to at least extend part way into the sheetrock to preserve the fireproof theory.
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