I have a new building and ran cable through the studs. I've started hanging 7/16" sheathing on one wall and a part of another. I used 2-3/8 inch framing nails and I tried to stay about 6 inches from the wires on either side.

Now I am concerned that I hit wires. I don't think I did but where the wires run up the studs for example I just don't know. Would you cut sections of the walls out and add nail guards? Thanks in advance.

P.S. The walls are staying plywood so it doesn't have to look perfect

  • Did you properly center the cables in the framing? What size are the studs?
    – isherwood
    Commented Mar 25, 2023 at 14:33
  • 1
    @JimStewart, 2-3/8" is roughly the equivalent of an 8d nail and it's standard for wall sheathing in my area. You're right, but some codes may require slightly longer nails, if only out of convention.
    – isherwood
    Commented Mar 25, 2023 at 17:34
  • 1
    The shower of sparks? That unpleasant tingling sensation in your hammer-arm? (humour)
    – Criggie
    Commented Mar 26, 2023 at 18:40

2 Answers 2


This is why code requires cables to be centered. If you did that you have nothing to worry about. In the dozens of garages I've built with 2x4 walls and 7d, 8d, or 2-3/8" pneumatic nails I don't recall ever having such a problem.

If you didn't follow code and best practice with your wiring, your next move is a matter of risk tolerance. Do as you see fit. If you did, move on.

As for how you'd tell... you won't. Or you will. If you hit a conductor and damaged it badly enough it'll either break or short the circuit or it'll cause localized overheating. You won't know about the latter until you smell smoke.

  • Ideally, the contractor would also have put a metal plate over that part of the stud, specifically to force folks to pause and think. But while that's best practice, don't count on it, especially in older buildings. And I'm not sure it would significantly slow a pneumatic nailer.
    – keshlam
    Commented Mar 25, 2023 at 16:23
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    It would take hundreds of such plates in a fully wired garage. It's not practical to do or reasonable to expect.
    – isherwood
    Commented Mar 25, 2023 at 17:35
  • I wouldn't count on it, certainly. It's mostly used in the places where the wire can't be centered. But I'd still argue that it's best practice, just not common practice.
    – keshlam
    Commented Mar 25, 2023 at 18:10
  • When electrical cables go into a stud bay through the top plate are they loose in the bay until near a device box where they are stapled? Or are they stapled to a stud all the way down? Commented Mar 25, 2023 at 18:31
  • They'd be stapled near the plate and near the box and at intervals between.
    – isherwood
    Commented Mar 26, 2023 at 19:26

That's why wires are required to be a certain depth from the wall, or use "nail plates" to guard from wayward nails. However the mandatory depth only allows for about 1-3/4" penetration measuring from the finished surface (so probably 1-1/4" in your case). So those nails are too long to be sure. In the future use appropriate fasteners; I myself am a huge fan of Torx deck screws. Yes, they're more expensive. But so are WAGO splices, and everyone swears by those.

To test the circuits for damage, the ideal approach is to use a borescope to look for places cables are close enough to the wall to be in the nail zone. However you can also put "AFCI devices which take the neutral wire" * along the circuit before the area in question, and they will detect and trip on any shorting or broken-wire arcing which may occur due to damage.

* So not GE's latest AFCIs or Siemens' tandem AFCI breakers, which do not use the neutral wire because they don't provide GFPE (weak GFCI) protection. In this case, GFPE is a virtue.

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