If I'm running wire through the crawl space for say a light switch in a wall above, but I plan on moving said wall 8 feet further away in a couple years is it legal/advisable to leave extra wire coiled as shown in the picture to have it ready to go if/when it is needed? If - as I suspect - the answer is no, is there another way of doing so? BTW, the picture is of coax for illustration purposes, but what I'm asking about would be 14/2 or 14/3 wire. It would be live and in use.

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2 Answers 2


There's nothing against having excess length, but you want to avoid tightly bundled in power wiring due to heat dissipation concerns.

So coiling it up is inadvisable. If you plan to move it 8 feet, run it 4 feet in that direction and then back, rather than making a coil - or 4 feet in any direction and then back, if the 8 feet won't be down in the crawlspace. Use a cable attachment that allows you to release the cable without damage (i.e. not stapling - one of the plastic clip products, perhaps.)

Gardner-Bender cable clip picture from Amazon

  • 1
    Lovely. It will all be in the crawl space, and I happen to have some of those clips. Love when a solution is that simple.
    – Trevor
    Jan 23, 2022 at 14:14
  • Most of my extensions mention to spread them out before using. Think part is heat and part might be electromagnet fields generated in coiled up cables.
    – crip659
    Jan 23, 2022 at 15:37
  • 17
    Physics and normal extension cord construction don't allow for much on the electromagnetic field front, since the field induced by the hot wire current is equal and opposite the field induced by the neutral wire current, so the net field is nothing to speak of.
    – Ecnerwal
    Jan 23, 2022 at 15:50
  • 1
    when running back and forth make sure you still meet the clearance requirements so that for instance a bend in the wire is not too close to the floor / ceiling where it might be punctured by a future hardwood floor nail or misaligned drywall panel screw etc..
    – P2000
    Jan 23, 2022 at 19:03

Your best bet it to put in a junction box where you would have coiled the wire. That way you can remove / abandon the wire to the switch, and run new wire to the new switch when you build the wall. The existing feed would enter the junction box and then you can go wherever you want.

  • 1
    This is a great idea as well. With the price of wire today, it might actually be cheaper to buy an extra box, cover & wire nuts than leave 8'+ of copper laying unused...
    – FreeMan
    Jan 24, 2022 at 19:14

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