I'm in the middle of a bathroom remodel, and had to take off some drywall to get the tub in, then thought I may as well take all the drywall on that side off to give me an easier taping job. Also I wanted to replace another section of the polybutylene pipe while I had the chance.

The Goal

Then I thought now would be a good opportunity to add a few extra receptacles around our (new) vanity. We bought a 36" vanity, and would like to put one receptacle above the left side of the vanity, and another lower down for charging devices in the vanity (there's no back to the vanity).

The Details

I'd like to tap off the receptacle shown in the upper right. This receptacle is on the same circuit as three others in each of the three other bathrooms in the house, all four protected by one GFCI receptacle in the adjacent bathroom. I'd like to avoid cutting out the drywall around the receptacle itself, and instead cut out a section towards the bottom and tap off there so I don't have to be as concerned about doing a fantastic taping job since it will be hidden by the vanity (the strong glancing light from the vanity light would make the receptacle tape job very difficult I think).

If I tee off the wire towards the bottom of the floor, I believe I'd have to put a box in with a blank plate to make the connection accessible. Since the vanity would be covering it, would this not be acceptable? In that case I could put a plate on the other side of the wall in our bedroom.

Is there anything wrong with my plan?

Wall behind vanity

  • You're going to need a new GFCI protected circuit, and possibly tamper resistant receptacles (depending on the adopted code in your area). You cannot tap off of the existing circuit, unless it is a 20A circuit that supplies only that bathroom.
    – Tester101
    Commented Mar 18, 2013 at 13:16
  • @Tester101 It definitely fails that criteria, as all four bathrooms (2 full, 2 half) are on one circuit. I'm going to look into running a new circuit to this bathroom as Paul suggested.
    – joshdoe
    Commented Mar 18, 2013 at 14:11
  • I thought you could serve receptacles in more than one bathroom with a single 20A bathroom circuit but you could not serve any non-bathroom space.
    – Craig
    Commented Mar 18, 2013 at 16:16
  • @Craig Just checked the 2011 NEC, and it seems you're right. 210.11(C)(3) makes no mention of the number of bathrooms that can be served by a single 20A circuit, but that only bathroom receptacle outlets can be on that one circuit. There is an exception that if only one bathroom is served by a single 20A circuit, then other equipment in that same bathroom can be supplied by that circuit (e.g. lighting). Of course if you have several teenage girls and several bathrooms, it may be prudent to give each bathroom its own 20A circuit. :)
    – joshdoe
    Commented Mar 18, 2013 at 20:19

1 Answer 1


I see a couple of issues. The first is that your three bathrooms are not wired properly, and you should take this opportunity to fix them! You should not have outlets in three different bathrooms all on one circuit. Each bathroom should have its own 20 amp circuit. The reason for this is that hair dryers, curling irons, etc. use a lot of juice.

Your second issue is going to be the ability to "T" off of an existing cable at some point below the existing outlet. Assuming that the cable actually does run down the wall below that outlet, I would imagine it runs in a fairly straight line without a bunch of slack, right? Unfortunately, in order to "T" off of it, you would have to cut that cable and then have enough slack to pull 6 inches or so from each side of the cut into a new box, where you would join those two ends with your new cable. It's highly unlikely that your wire has a foot of slack in it that you could use for this purpose. If it did have a foot of slack, then you would be better off just pulling it through the actual hole for the new outlet and connecting the two ends (from the top and bottom of the cut) to the screws on your new outlet - no need for a new cable or a secondary hole anywhere.

All that said, here's how I would go about accomplishing what you want to do without cutting any unnecessary drywall:

  • Turn off the power and remove that outlet in the picture from the box.
  • Put a crowbar or something against the inside of the box, and hit it with a hammer a couple of times - just enough to make the box start to lean away from the stud it's attached to so you can see the sides of the nails.
  • Slide in the blade of a reciprocating saw and cut off the nails.
  • Trace the old cable from the outlet back to the outlet that was feeding it power.
  • Disconnect the cable from there and pull it out of the wall if possible. If it's fastened inside the wall, just cut it off and leave it in place.
  • Run a new 12-2 cable from your breaker box to the new hole you cut in your drywall for the outlet under your vanity. Run another 12-2 cable from that location to the hole your old outlet box came out of.
  • Get a pair of "old work" single gang boxes. These are designed to slide into the small rectangular hole in your drywall and clamp onto it from the back with no need to cut giant holes that will require taping and repair.
  • Pull the cables into those boxes and fasten the boxes to the wall.
  • Install a new GFCI outlet under the sink using the directions in the package.
  • Install a new 15 amp outlet where the old one was located above the sink.
  • Thanks for the detailed suggestion. Sounds like the most difficult part of this will be running a new cable to the breaker box in the basement. This bathroom is on the second floor, so perhaps my best bet is to run the cable up into the attic, to the side of the house (this is a townhouse by the way), then if I'm lucky there'll be space to run it down next to the cold air return duct.
    – joshdoe
    Commented Mar 18, 2013 at 13:57
  • Just run it up to your attic and then find the top of that wall that the current outlet is in. Use a 5/8" spade bit to drill a hole in the top plate of that wall right above the existing outlet, then drop the end of the wire right down to the top outlet. Put your GFCI in that one, and then run another cable from the "load" side of the GFCI outlet down to the one under your sink.
    – Paul
    Commented Mar 19, 2013 at 1:58
  • That part sounds straightforward, however I finally squeezed through our scuttle hole into the attic, and there doesn't seem to be a clear route to the basement. The main vent stack does go straight through to the basement, however in at least the first floor the hole in the subfloor isn't large enough to fit the cable through, and even if I make an opening who knows if there'll be room where it goes through the second floor. Seems like I'd need a 9 foot flex drill bit plus a snake cam to pull this off.
    – joshdoe
    Commented Mar 22, 2013 at 2:34
  • Oh, and I have determined that not only are all four bathroom receptacles on one 15A circuit, but three of the bathroom lights are on it as well, AND there are at least two other receptacles and one light on it as well. Unless I run a new 20A circuit to this bathroom, I probably shouldn't touch a thing.
    – joshdoe
    Commented Mar 22, 2013 at 2:37

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