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We're getting ready to finish our basement. The basement is already wired for electricity with wall-mounted metal outlet boxes.

Electrical box enter image description hereenter image description here

However, the existing boxes will be way too shallow once the insulation and framing are put in. The existing box is 1.5" deep. We're planning to put in 2" XPS, and I'm told the chalk line for the top and bottom plates should be 4" in front of the insulation. So that would put the front edge of the framing 6" from the foundation wall. The guy at the hardware store suggested I use box extensions to bring the box out further. But the extensions are 1.5" so I would need to use three of them to bring the box out to 6". That seems a little awkward to me, and I have to do this with 8 outlets.

Are extensions the best way? Or can I instead remove the existing box and replace it with one that will mount to the frame stud? Should I use metal or plastic? Would I need to extend the conduit to reach the new box? Or should I just bite the bullet and call an electrician?

In any case I will also need to extend the wires, as there is not enough slack.

  • Are you OK with re-pulling the wires, or would you rather avoid that? – ThreePhaseEel Apr 29 '18 at 20:48
  • Do you mean running new wire through the conduit poles? I'd rather avoid that, if possible. Some of the poles are close to a junction box, so it wouldn't be too bad, but some run the whole length of the house before terminating, so that would be a pain. Unless you just mean pulling the wire out of the conduit and running it from the joist down the framing instead; that wouldn't be too bad. – Todd Apr 29 '18 at 20:52
  • Are the conduits protective sleeves housing NM cables, or an actual wiring method with individual THHN inside them? – ThreePhaseEel Apr 29 '18 at 23:50
  • @ThreePhaseEel I added a couple pictures to help clarify. Basically, the NM cable just runs down through the conduit from the joist. – Todd Apr 30 '18 at 1:27
  • @Tyson Would you mind moving your response to an answer instead of a comment? – Todd Apr 30 '18 at 1:31
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This is so easy, you'll laugh.

  • unfish the cable out of the last segment of conduit
  • pull the conduit off the wall
  • use a conduit bender to put a slight S- curve in the conduit, so it's out from the wall 4.5" more than it was.
  • put the conduit back on the wall
  • fish the cable back in. It will still reach! It is still the same length as the conduit.

Now, the junction box is 4.5" proud of the wall, and 1" or so higher up the wall. Build your wall, make sure to include a hard point to mount the junction box.

  • Perfect! I had the exact same idea, but not having ever done that myself I wasn't 100% certain that it was the right thing to do, so I didn't answer it myself. – manassehkatz-Reinstate Monica Apr 30 '18 at 1:58
  • That's interesting. It would leave the outlets a bit high on the wall. They are currently about 18", which is already high, and then this method would make them even higher. However, I might be able to live with that. – Todd Apr 30 '18 at 3:19
  • Although, now I'm wondering why I need to put the conduit back on the wall. Couldn't I just move the conduit to the stud once I put the framing up? Then I wouldn't need to bend it. But would I even need the conduit then? Could I just run the cable right down the stud? Or does it need to be in some kind of conduit since it's near the foundation? – Todd Apr 30 '18 at 3:28
  • I don't know what your local code says about running Romex in-wall (here in NYC it's no-go, the code requires armored cable), but it's certainly safer to have the conduit protecting it. You'll thank yourself if anyone accidentally tries to put a nail through one of the lines. ...But if you plan to ever install bulkier receptacles (GFCI, surge protecting, USB-charging), or even just more than one pair per double-gang box, you'll want MUCH deeper boxes. I'd replace those with 3"-3.5" deep, because why not? You have the room. And you'll again thank yourself when working inside them. – FeRD Apr 30 '18 at 6:46
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    @todd sure, those ways would work too. If you stay with the 4x4 steel boxes, consider 1-gang mud rings. They give you plenty (nearly 30ci) of space. – Harper - Reinstate Monica Apr 30 '18 at 13:47
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Basically you need to start over.

You can’t conceal junction boxes, they must be left accessible. Those outlets are likely much higher on the wall than you will want height wise in a finished space, extending the wire is not an option unless you leave accessible junction boxes.

Supply-wise you can only really reside the outlet(if they didn’t use backstabs), but you need a different style box and plate. You won’t need conduit with framing and wallboard/drywall. For the extra cost of junction boxes etc, you might as well just buy new wire and do it correctly and straight forward from the beginning. – 

  • Good point about the height of the boxes, but they aren't too bad. They are currently about 18" off the floor. Even if they went up a few inches, that wouldn't be bad, though probably higher than I would ideally like. – Todd May 1 '18 at 0:49
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You are converting from exposed wiring to "in wall".making for a few options.key is where the wires are in the ceiling. Estimate where your finished outlets&switches are going to be, international code is a good guide, then convert your metal conduit to pvc(gray, just like white drain pipe)within ceiling ,then puzzle out reaching your boxes with "extra" wire. Conduit is only necessary because exposed wire cannot be used in conduit &conduit wire cannot be exposed even within a wall. I think ,since you are not experienced you may be able to get away with plastic boxes, though each inspector has their own pet peeves.

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    "exposed wire cannot be used in conduit" <<< WRONG! See NEC 334.15(B) for details on what's going on in the OP's install (hint: the conduit's just a protective sleeve to keep the NM from getting banged up) – ThreePhaseEel May 1 '18 at 0:01
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It looks like you have romex wire in conduit, which is a bozo no-no. Pull all the conduit off, and you'll have a great, inexpensive starting point. Install wire as a normal wall build; piece of cake.

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    This is a case where conduit is used as a sleeve to protect the NM from physical damage, as called out in NEC 334.15(B). – ThreePhaseEel May 1 '18 at 0:00

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