Just a quick question,I've asked around, and have had conflicting answers.

Basically, can you strip UF-B (12/2) into its individual wires and run it through PVC conduit. I was planning on just running the 12/2 through the conduit ( i would be using 3/4 "),, but if it was allowed to strip that UF-B down i would be able to use 1/2 conduit?

The local electrical store assured me that running the 12/2 UF-B through 1/2" conduit is acceptable, but i understood that it had to be a certain size on conjunction to the wire size.

  • 2
    Even if this were allowed, stripping wire from UF-B is annoying painful work! I'm cheap and I'd rather go buy wire by the foot than try to salvage it from UF-B.
    – jay613
    Mar 31, 2022 at 16:03
  • Have you ever tried to strip the wires out of UF jacketing? I have... good luck. Apr 1, 2022 at 0:39

2 Answers 2


People often toss out the word "conduit" without really saying what they are doing with the conduit.

Conduit being fully run, end-to-end as a wiring method

Then you must follow all the conduit rules. The conduit must begin and end in a junction box. Thermal derate (no more than four 15-20A circuits in a pipe) must be respected. Physical fill rules must be respected, which almost precludes the use of UF cable, as it is very wide for its size, and thus requires a huge conduit (e.g. 2" for #6 conduit).

For a single cable, a shortcut is that the minimum pipe size ID is 138% of the maximum cable width.

The conduit must be fully built, glued, filled and tamped before any wires are PULLED into it. That means the conduit must be built to be pullable - with broad sweeps at inaccessible curves, and "pulling points" where feasible.

Cable in conduit is generally considered a nightmare, and very difficult to pull.

However this is not the same thing as

A stick of random pipe merely as a damage shield in one location

Sometimes when you are running NM, UF or SE cable, you have a short distance where the cable needs an additional bit of protection from physical damage. E.G. because you cannot run inside a wall, must run on the surface of the wall, such as coming down the wall on a poured concrete basement wall.

You can use any bit of random metal for this protection (that is tough enough), including pipe, including pipe that is made to be conduit.

However, at that point you are not using it as "the conduit wiring method", you are using it only as a "random piece of metal" to provide additional damage protection.

In this case, the "conduit as a wiring method" rules do not apply. Pipe fill is not a concern - if it fits, it ships. You can slide the pipe over the cable as you go. The cable can exit the pipe without a junction box. It doesn't need to be electrical conduit types specifically - heck, it doesn't even need to be pipe.

It does need to meet certain standards for physical protection, and cheapo PVC pipe or conduit typically doesn't - it's too easily broken.

Since copper pipe is expensive and some PVC is insufficient, EMT metal tubing is often used.

And if you want to extend the EMT into one junction box and put a receptacle there, that is fine.

  • What i'm hoping to do is, run the UF from our electrical box to the side of the house, then pop up under the house behind the skirting ( we have a mobile home, so keeping it buried will be difficult,) have it goto the other side( 15 ft distance), then up to where our porch is and into a CFGI outlet....... is this do-able?
    – Jben04
    Mar 31, 2022 at 19:04
  • @Jben04 wow, you should have asked about that stuff lol. #1 deleted. #2 conduit must be at proper depth. 6" of cover for expensive RMC conduit, 18" for other conduit, 24" for UF no conduit. Other than that, Mrs. Lincoln, #3 it sounds like you are using it as a damage shield not a wiring method, so "easy mode". Mar 31, 2022 at 19:08
  • It cant be done even if its to a open porch that's not actually attached to the house?The house panel isnt full and there are slots still available.Only reason its going under the home is that its the shortest route to the porch, It would need a sub panel just for outlet,, thats the same as just a disconnect switch?
    – Jben04
    Mar 31, 2022 at 19:10
  • @Jben04 yes, I just re-read that. Forget my point #1 since you are not going to the MH, only to a point outside it. #2 and #3 still apply. Mar 31, 2022 at 19:11
  • Only reason its going under the home is that its the shortest route to the porch, It would need a sub panel just for an outlet,?, that would be the same as just a disconnect switch?
    – Jben04
    Mar 31, 2022 at 20:06

You cannot strip cable and use it in conduit, as the individual wires in the cable are not marked.

If someone made cable with the wires marked, you could do that, but nobody does, AFAIK.

One example of 12/2 UF I found claims the major diameter is 0.463 inches. For a single cable in conduit you treat that as a round wire of that diameter, and use the one-wire fill percentage of 53% of the area. The back of my envelope says 1/2" PVC (0.578" ID Schedule 40, smaller for Schedule 80) won't meet that spec. Even 1/2" EMT (0.622" ID) is not quite big enough.

3/4" PVC even at Schedule 80 (which is often needed, because it's required if the conduit is considered "exposed to damage") should work with an ID of 0.698" (which my envelope puts at ~44% fill.)

  • 1
    In addition to the wires not being marked for individual use, stripping UF-B is a royal pain! Stripping the sheath from NM-B is far easier, but just as big a code violation.
    – FreeMan
    Mar 31, 2022 at 15:11
  • So , i'm good with the UF in the 3/4 conduit.? And if i wanted to go through the 1/2", id need to pick up individual rolls of Thhn wire?
    – Jben04
    Mar 31, 2022 at 15:50
  • That is Correct. Though if you have limited needs, THHN by-the-foot costs more per foot, but less if you only need a few feet.
    – Ecnerwal
    Mar 31, 2022 at 16:18

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