I am replacing a direct-wired dishwasher. The house wire comes up from the basement in a small hole in the subfloor; unfortunately, the existing placement was exactly where the new dishwasher's leveling legs would be. So, I drilled a new hole further back, fished the house wire out through the old hole and up through the new. In so doing, the wire rubbed against a rough edge on my basement wall. After fishing the wire up the new hole, I noticed some minor damage to the insulation (pictures below). Note, in at least one place, the insulation is scratched enough that one edge of the scratch can be peeled back slightly.

Is damage like this minor enough to ignore altogether (it doesn't look like wires are exposed)? Should I perhaps wrap with electrical tape? Is a more substantial fix (involving hiring an electrician to splice / replace the wire) necessary?

Image #1: enter image description here

Image #2 enter image description here

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    I wouldn't be surprised if even the most experienced electricians caused "damage" like this without even noticing, or if they did notice, wouldn't even shrug at it. Kudos to the attention to detail, but I wouldn't recommend eyeing the rest of your electrical system with this level of scrutiny or you might go clinically insane Commented Apr 11, 2022 at 17:39
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    Based on the pictures, I don't actually think the insulation is damaged. It looks like there is some gunk on the outside of it that could probably be cleaned off, but doesn't need to be and I see no value in doing so. (Especially in the first picture, you can see where it comes off that you could grab with fingernails and peel off what might be dried caulking or similar.)
    – WBT
    Commented Apr 11, 2022 at 20:09

2 Answers 2


You can tape it if you like but it is fine as is. I am assuming the rest of the wire is clear without scuffing marks etc.

  • Thanks. There is some scuffing elsewhere (including a tiny nick or two) but the above is what I perceive to be the worst of it.
    – diy8675309
    Commented Apr 10, 2022 at 18:59
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    Agree, fine as is. My electrician had the sheathing torn on some 14/2. The electrical inspector saw it and since the individual conductors inside did not show any damage he just had me electrical tape the torn sheathing. Commented Apr 10, 2022 at 20:37

Good on you for being rather safe than sorry and asking about electricity issues you are unsure about, but this "damage" is purely cosmetic and does not represent any safety concerns1.

A wire like that has double insulation, e.g. there are two (or three) individual wires inside with its own insulation inside with an additional outer insulation covering the group of wires

So unless both layers of insulation gets damaged there is no exposure (in which case electrical tape can be used to amend for minor damages, although that ought to be judged with proper knowledge to say if it is minor or not).

1 That is not to say that as long as the outer insulation has no holes there is unconditionally no problems. If you say lose a heavy object with sharp corners on top of a wire so that it gets a dent but the insulation is still whole, there could be a problem with a metal wire inside being damaged and result in a break or increased resistance.

  • Thank you! That greatly improves my peace of mind.
    – diy8675309
    Commented Apr 11, 2022 at 15:45

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