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I'm in the process of finishing my basement (it has taken 1.5 years so far, and is still progressing). I'm working on roughing-in the electrical at the moment.

Against the 2x4 studs, I installed deep j-boxes (this product) instead of the smaller ones, primarily to give me more space when messing around with 12ga wires.

The city electrical inspector wanted me to protect the wires going into these boxes (and possibly, the boxes themselves) from stray nails, etc. The problem is that I can't seem to find 1/16" steel plates that are wide enough to span the gap between two studs. I could possibly use the 3" or so wide nail plates, with a line of these installed onto a furring strip or similar, but that would still leave small spaces for an errant nail or screw to slip into.

I bought a sheet of aluminum (this product), and am planning on cutting this into long strips, possibly doubling it over, and screwing it into the studs to protect the entire length of wire and back of each box.

Is this feasible? OK per NEC? Am I giving the inspector another reason to deny approval of my electrical rough-in?

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    Why couldn't you get a sheet of 1/16" steel? The aluminum is too soft.
    – Dan D.
    Apr 7, 2016 at 15:55
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    @DanD., I already own a good pair of tin snips that will easily cut the AL plate, but don't have any tools that can custom-cut 1/16" steel. Would rather not buy a special tool just to cut metal, which I won't need to use again.
    – alt
    Apr 7, 2016 at 15:57
  • you can buy a cutoff wheel sized for a circular saw, and cut the steel that way. I would ask the inspector if the aluminum is OK (since as @ArchonOSX says, code specifically refers to holes through studs), and if he says no, offer to double it up. If he still says no, ask him to help you find a way to use the smaller plates if he's going to insist on using steel.
    – DrewJordan
    Apr 7, 2016 at 17:19
  • Maybe other people here are getting it, but I don't understand the mechanics of what you're being asked for. Can you post a picture? And for what it's worth, a small handheld angle grinder is a super useful tool to have, imho. Mine comes out all the time.
    – Aloysius Defenestrate
    Apr 7, 2016 at 23:24

3 Answers 3

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You need to protect the wires where they enter the box, but you don't have to span the entire stud cavity. You just need to protect the wire as far as it takes to reach more than 1-1/4" from the stud face (or the back of the drywall).

I'd pick up some double-gang box covers and nail them to the studs at box height and extending toward the cavity that the box is in. If you feel like you need more width, get 3-gang plates.

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  • Looks like this is the exact thing I need. The thickness is right, can just be nailed into place, and should protect the wires just so. Thank you!
    – alt
    Apr 7, 2016 at 19:51
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The Code specifically indicates clearance from the edge of a framing member. It makes no mention of clearance between studs.

From the NEC:

300.4 (A)(1) Bored Holes. In both exposed and concealed locations, where a cable or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than 32 mm (11⁄4 in.) from the nearest edge of the wood member. Where this distance cannot be maintained, the cable or raceway shall be protected from penetration by screws or nails by a steel plate(s) or bushing(s), at least 1.6 mm (1⁄16 in.) thick, and of appropriate length and width installed to cover the area of the wiring.

Ask the inspector to cite the specific section of the Code that he is using to require you to do this.

If they are going to require it they need to cite it.

Good luck!

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  • Thanks @ArchonOSX. Also, I would to add that, logically, there shouldn't be any nails going through the wall where there aren't any studs.
    – Ben Welborn
    Apr 7, 2016 at 16:44
  • That's an interesting observation... I'll certainly ask for a code citation. But I'm curious: is there no provision in the code that discusses the safety of an junction box and the cables leading into and out of it? This is the only issue I'm trying to work around. (Just to be complete: he did mention that all knockouts must be either present or used, and that cables must be stapled within 8" of the box - though code says 12" - and that he would like to see at least 4" of cable inside the box; all of these requirements have been met).
    – alt
    Apr 7, 2016 at 17:20
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    The 8" requirement is for device boxes without any cable clamps. J-boxes need to have some type of cable clamping mechanisms and then they can be stapled within 12" and every 4 1\2' thereafter. The requirement for nailer plates is to protect wires in framing members since that is where the drywall gets anchored. Drywallers don't purposely screw or nail in the middle of a cavity. The cable sheath should be stripped and you should have 6" of free conductor in the j-box.
    – ArchonOSX
    Apr 8, 2016 at 1:29
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I think that the inspector meant that you need to use nail plates (or nail stops) where there are holes drilled in the studs for the wires to pass through. enter image description here

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  • Hey, thanks for your reply. But nope, I don't have any such wires inside of studs; all of my drilled holes are at least 1.5" from each edge. The inspector specifically referred to cables going into the deep j-boxes being too close to the other edge of the stud.
    – alt
    Apr 7, 2016 at 16:23

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