3

I am in the process of adding an outlet to a wall in a previously renovated basement. The wall is drywall, mounted to furring strips which are attached to the cement wall.

My two options as I see it are:

  1. Externally mounted box run horizontally like wiremold or EMT and a handybox, or
  2. Cut a hole in the drywall, mount a handy box directly to the cement. Fish NM down vertically between the drywall and cement wall into the handybox. It leaves about 3/4" of the box jutting out from the wall. Patch around it, paint, good to go.

Which would be more "proper"? Any code concerns?

Edit: added image of the completed project.

enter image description here

  • you don't say how thick the furring strips are. Code requires conduit if the wires are less than 1.25 (sometimes 1.5) inches from the back of the drywall. – Paul Nov 3 '16 at 1:55
  • Thanks for responding! 1" furring strip. Does that leave me with surface conduit or would armored cable be possible? – Peter J Nov 3 '16 at 1:57
  • It's certainly ok to remove a bit of concrete foundation to get a box to fit flush. Just messy and hard to do without proper tools. – Paul Nov 3 '16 at 3:04
  • @Paul -- there's also no requirement for boxes to fit flush with the wall -- they just can't be recessed into it. – ThreePhaseEel Nov 3 '16 at 3:11
  • Some relevant discussion regarding BX vs EMT vs plate near the finished surface: diy.stackexchange.com/a/38680/4565 – Paul Nov 3 '16 at 16:03
2

You have three choices here:

  1. Run the NM cable in-wall with a sheet steel protector at least 1.6mm thick between the cable and the wall surface (to keep those pesky nails away)
  2. Run conduit in-wall -- a 3/8" trade size EMT should squeeze down there OK although you'll be tight on wire fill with that. You might be able to fit 1/2" EMT -- I'd try it at least, and use the 3/8" if 1/2" doesn't fit in the gap.
  3. Run surface raceway or conduit, if you'd rather the industrial aesthetic.

All three will meet Code -- it really depends on cost and what skills and materials you have available to you.

  • Excellent...thank you for this answer. Is BX/MC cable not allowed? The drywall is already installed, trying to not break up the wall if possible, and I don't know how I'd get the sheet metal or EMT back there. If that's the case, maybe I go industrial. :-) – Peter J Nov 3 '16 at 2:35
  • @PeterJ -- MC cable would work, but you'd still have to put the nail plate in there, and NM's like half the price :P – ThreePhaseEel Nov 3 '16 at 2:52
  • @Paul -- could you clarify what you're responding to? – ThreePhaseEel Nov 3 '16 at 3:10
  • @ThreePhaseEel moved comment. – Paul Nov 3 '16 at 16:04
  • Just to put a little closure here, I went with #3: wiremold (basically square EMT that extends from existing outlets.). Worked great. – Peter J Dec 6 '16 at 14:44

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