Cutting drywall to install electrical wiring

[brianl703]

I need to run a new 20-amp circuit from the circuit breaker panel to the kitchen sink for a water heater.

Both the breaker panel and the kitchen sink are on the same wall, there is a slab underneath, so the wiring MUST go through the wall and about 6-7 studs.

What is the best/easiest way to cut the drywall? Preferably without tearing the paper on the back of it? A drywall saw, a rotozip type tool, a dremel with the drywall cutting attachement, or..? What I intend to do is cut a strip of drywall about 4" wide from above the circuit breaker panel to above the kitchen sink, and then drop the wire down behind the dishwasher, and from there to the sink. Then I'll run the cable, notching/drilling the studs as needed (if I can't find/use the holes for the existing wiring to the dishwasher..I'll use a toner and probe to find them it the wall before I cut it open), and installing nail guards as needed, and then re-install the cut drywall and then tape and mud it.

Actually connecting the cable to the heater and the circuit breaker panel is no problem--I've done that many times--but I have never had to run a cable horizontally in a wall before.

 

[Pablo]

All of the above will work. You sound like you know what you are doing! I mean I have scored the paper and whammed it with a hammmer (destructive!) and I have cut it with a rotory tool (best choice).

Can you run the wire above? Where (how high?) will the cut be?

 

[brianl703]

There's a sliding glass door (it's an exterior wall) between the breaker panel and the kitchen sink, so it's gotta go above the patio door, and then down to the breaker panel and down behind the dishwasher. I'd guess it'll be about 4-5 inches from the ceiling.

 

[Larry the Cable Guy]

Sounds like you have it figured out. I vote for the rotozip tool - just be careful of existing concealed wiring.

I'd try and center it between the top of the header and the bottom of the double top plates where above the slider.

Steve

 

[kenw]

you can't go into the attic to make the horizontal run? (or is it 2 story?)

I've used a regular circular saw with a shallow depth for this type of work often, tho without any issues. Circular saw or dremel, set the depth to keep from going deeper than the sheetrock thickness.

 

[brianl703]

It's 2-story. I'm going to try to use the toner and probe to find the existing wiring to the dishwasher so I know where it is even before I cut into the wall. I think the wiring to the diswasher probably goes above the sliding door, the breaker panel is about a foot from the sliding door.

 

[Amkeer]

Keyhole saw, drywall saw. The slot really only needs to be 1-1.5 inches wide or the width of the plate sideways. If you do it shallow enough you do not have to run strips of drywall you can just use 60 minute mud and mesh tape.

 

[XS650]

quote:

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Originally posted by brianl703:
I need to run a new 20-amp circuit from the circuit breaker panel to the kitchen sink for a water heater.

Both the breaker panel and the kitchen sink are on the same wall, there is a slab underneath, so the wiring MUST go through the wall and about 6-7 studs.

What is the best/easiest way to cut the drywall? Preferably without tearing the paper on the back of it? A drywall saw, a rotozip type tool, a dremel with the drywall cutting attachement, or..? What I intend to do is cut a strip of drywall about 4" wide from above the circuit breaker panel to above the kitchen sink,

---

Brian, I made the same kind of run along about 12 feet of wall a couple of years ago.

I screwed a straight piece of lumber to the wall and used it as guide for a Roto Zip and cut about a 4 inch high strip of drywall out. I carefully removed the drywall without breaking it. After I was done, I put the drywall back in the slot I removed it from so I didn't need to cut new drywall to fil. Sounds like whatyou are planning. It worked out real nice.

If you use aRoto Zip, be sure to get the bits that cut all the way to the end and then only cut deep enough to just go all the way through the dry wall. You never know what's inside a wall.

While you have the patient open with a 4 inch wide incision, it's an ideal time to install additional outlet boxes. That was the primary reason I cut my wall open.

As I do more drywall work I'm using a knife more and a roto-zip less. It's a lot less messy and by the time you set up to do an accurate job it's quick.


It's hard to make along cut really straight with a Roto-Zip unless you use a guide, it's worth the time it takes to screw a straight edged board to the wall.

 

[brianl703]

Thanks for all of the info. The idea of screwing a piece of wood to the wall is a good one. Today I bought the rest of the plumbing and electrical supplies I'll need to install this water heater.

It barely fits through the door to the under-sink cabinet, it's a 6-gallon Ariston with a 1500W element and a 12-gallon-per-hour recovery rate with a 90F rise. That should be sufficient for a dishwasher. What was under there is a 2.5 gallon water heater tapped to the dishwasher circuit. The dishwasher was never used at all but frankly it simply wouldn't have worked very well that way. In addition to running out of hot water, the breaker would probably trip as the water heater and the dishwasher's heating elements came on.

The reason for the waterheater is that the hotwater line to the kitchen sink embedded in the slab developed a leak. This was the half-*** fix the previous owner did. This is my mom's house, not mine. I think some money got paid to the building inspector when that house was built, and I'm not talking about permit fees.