How do I repair a buried UF cable sheath?

Question

I have a UF cable running a 20amp circuit from my house to a shed in NJ. Probably at least 30 years old, house is 50 yo. Just bought it. Today while digging a drainage trench I found out the hard way that the UF cable is only 12 inches below ground, and nicked the outer sheath of the wire exposing the black wire sheath under it. No bare wires or anything, just the outer sheath, and small. I'm in the process of gutting the shed, so the breaker was already off for the cable.

Is there an easy and code-compliant way to repair the sheath itself without having to do a cut and underground splice kit?

Also, breaker is not currently GFCI but I plan on putting one in. I believe 12" depth with GFCI protection is succient for direct burial, correct? Hoping I can keep the UF cable as-is and use it, since half of it is under a deck. Thanks in advance!

Answer 1

20A with GFCI is allowed to be 12" deep, yes (residential branch circuit, 120V or less, with GFCI protection, Table 300.5, Column 4, Note 4.)

I'm not sure exactly what code has to say on the particular subject of minor jacket damage in situ. I'd be inclined to wrap it well (like 6" in either direction and two layers) with "self-fusing" electrical splicing tape and call it a day. I would advise (even if only in the area you dug up) installing Buried Electric Line Below tape in the trench well above the cable. It might be worth installing a handhole (what a junction box for buried cables is) at the point of the repair, in case it degrades further and requires an actual splice, later.

If you wanted to just splice it, you'd probably need two handholes to provide the required slack, and a short piece of extra cable, and then you'd use a wet-rated splicing method in both handholes to make the splices. Might just be able to do it in one, if it's well-centered over the damaged spot, and big enough (will still need extra wire.) One version of that (not one I'd suggest most people try with easier options now made, but it illustrates a point about the previous paragraph) is to use split bolt connectors wrapped with self-fusing splicing tape for waterproofing.

In general, Buried Electric Line Below tape saves a lot of pain, if it's installed far enough above a buried line to be easily found BEFORE you hit things with a shovel. If you are ever burying a line, put it in.