Putting electrical fixtures in a shallow wall.

RobertS

This customer has gutted a bedroom. It is an old house with plaster and lath. One of the walls has the studs turned flat so it is actually only 2" deep. One side of the wall is open. Can I legally run wires safely in that wall. I have to come down from the attic to run the wires. It's a no weight bearing junk wall. I would tear it out and replace it with a new wall. I am concerned with drywall screws or picture hanging hitting the wire. I found knob, and tube wires cut off, and plastered in the wall. Yes they were hot.

CowboyAndy

No. My house is the exact same way. A standard 18CI box physically wont fit, and a shallow metal box is only good if you are only running 1 cable to each box because of fill. On top of that, with the stud being 2" (i am assuming rough cut, right?) you cannot achieve the 1 1/4" back from finished surface.

I have seen guys double up the studs, or use 1" furring strips to bring it out just enough to achieve 1 1/4". It would be a good idea to use metal protection plates, too.

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jrclen

I wonder what your customers would think about you coming to a do it yourself forum to find out how to do your electrical contracting work?

chris75

Whats wrong with a 4"sq box and a plaster ring?

Who said you needed to be 1 1/4 from the finished surface? If your going to post information, at least find the information in the NEC first... and stop shooting from the hip....

chris75

Take a look at 300.4 (D)

CowboyAndy

The back of a finished surface (drywall for example) would be right against the outside edge of the framing member. How is that any different?


And I did not suggest a 4" box with a mud ring because I have no experience with them.

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chris75

Maybe I misread exactly what you were trying to say, were you trying to say you cannot drill the studs or just saying you cannot have a wire in between the studs? Either way the picture I posted shows the correct installation...

CowboyAndy

No, All I was saying is that you need to have that 1 1/4", and if you have a 2" stud and drull a 3/8 hole through the center, you don't have 1 1/4" on both sides. Using a 1" furring strip gives you JUST ENOUGH space. Using another 2/x on top of the existing stud gives you even more clearence.

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chris75

okay cool... sorry I misread your post...

bwinters12

Furring out the wall is overkill. If you are worried about nails going into the wire just sleve the wire in emt or pvc conduit.

CowboyAndy

It's cool... I tend to misread too, and have done the same. It's all good.
I guess its a matter of preference. Personally I think that would be overkill, plus more work than needed. I could fur out a 10' wall in about 20 min and be done with it.

Using conduit, there is assembeling the conduit fitting and such, and aren't you supposed to use thhn in it? Then you have to change over from romex to thhn, that inclused buying wire you may not already have, etc.



(correct me if I am wrong about using romex in conduit, unless it is only for a short distance and only for physical protection?)

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bwinters12

emt or pvc are both acceptable methods for protecting NM against physical damage.(334.12 B). You do not need to change over to THHN.

220/221

Yeah, that ^

CowboyAndy

Is there a certain length that you can do it for?

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chris75

Maybe required to obtain the proper insulation value anyway.... just my 2 cents... I know I would fur it out for insulation alone...