Locating an outlet box buried behind sheetrock...

[sw_ross]

I've had to locate a lot of buried receptacle and switch boxes, usually without too much difficulty.
Usually you know the height of the box, and with a 4-foot straight edge you can pivot on the high spot. Also use a stud finder to pinpoint the stud nearest your pivot point to fine tune where to drill a 1/8th inch hole with a feeler bit.

Today I had a smoke detector outlet box buried in the ceiling. The straight edge can find a slight high spot, but not an exact spot. We usually just nail up smoke detector boxes wherever it works best and doesn't interfere with the lighting lay-out, so I don't have a measured reference point to go off of.

I don't want to start cutting into this persons nicely textured ceiling until I have a better idea of the location.
Is there any way to trace a specific wire behind sheetrock? What about the greenlee cs8000 circuit tracer? I know it's kind of expensive, but I've been kind of thinking about this tool for other trouble-shooting purposes but don't know too much about it or if there's other tracers that would be better.

I would be interested in hearing any other techniques or methods that others use.

Sky

 

[ptonsparky]

My guys have gotten pretty good with the simple tone sets used for phone lines. They will trace a line in a wall and locate the cable end pretty quickly.

 

[kwired]

I have always found them with just a straight edge. Can't recall missing one either. Center of bulge is where you cut an inspection hole.

I don't worry about missing the box too much anyway because even if you cut hole perfectly, some drywall screw or nail will pop out when the cutout is done and the bulge in the sheet is able to flatten out. That happens almost every time also.

 

[ritelec]

If the tone generator works for you that would be great.

Rather than drilling, I use a thin screw drew driver smack it (plunge cut) with my hand (watch for some-type of tendinitis) or pliers. Send a snake up to help feel around (no head). Little dab of spackle and little paint if needed

Mind me asking......how did it get covered (the smoke as well as the outlets and switches)? Same job? Did a builder or contractor do it. Was "the person" the owner and did "the person" cover it?

I'd say do what you gotta do....you didn't cover it .....and defend yourself toward who ever did.

Your not a magician or have exray vision.

If patching and painting are going to be needed to be done so be it.

A box or two may get covered, it's bound to happen......but if someones not doing there job right, it should not reflect on you.

Maybe the box should have been addressed after rocking, before texture and paint???

All the best.

 

[ActionDave]

My guys have gotten pretty good with the simple tone sets used for phone lines. They will trace a line in a wall and locate the cable end pretty quickly.

That's what I use.

 

[Joethemechanic]

being that I never do residential I really don't know much about this kinda thing. but how does it happen? Do sheet-rockers have to move that fast.

All I can think of is way back in the day, every sheet-rocker I knew was either drunk or on meth, but usually both. Is it still that way?

 

[hurk27]

I have the greenlee, toner, stud finder, and several straight edges, Most times I just grab a straight edge, but there are those times when a toner or the greenlee will be needed, the greenlee can zero right in on the box if the circuit conductors feeding it are isolated from all other circuits, this includes the EGC's the toner can be a variable as the sound gets louder the closer you get to the conductors you have it connected to, but this can cause you to miss if the cable is run close to the dry wall such as along the side of a joist, conduit can be nice as you can just connect the greenlee and toner to the wires running in it using the toner to get you close to the box opening then zero in with the greenlee, I have an older greenlee I think a 7011 kit that was around $750.00, Double layer or thick drywall can be fun to find without a tracer as the dry wall doesn't hump as much.

PS if the dry wallers bury over 3 box's, I start billing the GC who forewords the bill or remove the amount from the dry wallers check, I can understand a couple but when we get more then 3 then these guys need to learn to slow down and make sure they mark the floor where the box's are, I also carry a digital camera and take photos of most of the locations, this helps when trying to locate them or remembering where runs are, after the house is don I just delete them off the camera unless the home owner want to pay to have them developed?

 

[ActionDave]

.....All I can think of is way back in the day, every sheet-rocker I knew was either drunk or on meth, but usually both. Is it still that way?

No. These days some of them are on probation.

 

[joelj]

I had to do this just the other day cleaning up after another "electrician". It was a room addition and they glued drywall over the stucco (leaving the stucco for a shear as per plans) and he mounted the boxes flush with the stucco so the drywall guys went right over them. I have the economy version tempo wire finder ($275 ish) and it worked perfectly. I don't use it a lot and had trouble justifying the Greenlee expense. My supply house will rent the Greenlee for $50 a day and credit against purchase.

 

[readydave8]

being that I never do residential I really don't know much about this kinda thing. but how does it happen? Do sheet-rockers have to move that fast.

All I can think of is way back in the day, every sheet-rocker I knew was either drunk or on meth, but usually both. Is it still that way?

How does it happen indeed. Many times the sheetrock hanger will argue when I say they covered a box, one that sticks in my mind was a kitchen with 6 cans, sheetrockers covered 3 and argued that the kitchen only had 3 cans, attic was accessible so it was easy to prove them wrong.

Another house only had 45 boxes, 12 were covered.

For a while I marked floor in front of box, too often by the time I came to trim finish floor was hiding my marks. I tried handing builder a can of orange spray paint thinking they'd be more aware of problems and help avert it, usually unused can still be at job when I went to find the buried boxes.

Luckily the economy crashed and I haven't had many new houses to wire. It's been a big relief.

 

[Ponchik]

.......... have exray vision.

It would be nice to be able to see what is behind the walls.:happyyes:

 

[kwired]

being that I never do residential I really don't know much about this kinda thing. but how does it happen? Do sheet-rockers have to move that fast.

All I can think of is way back in the day, every sheet-rocker I knew was either drunk or on meth, but usually both. Is it still that way?

Around here they mostly are spanish speaking folk. They are not paid by hour they are paid one price for whole job. (That is just the hanging crew)

This is motivation to work as fast as possible - the more jobs you can complete in a shorter time the more you make.

It also means a lot of wasted material - when you need a partial sheet - if you don't see a scrap immediately that will work you just cut it from a new sheet.

Cutouts get missed - and quite frequently, and most cutouts besides more obvious doors and windows are electrical cutouts. They measure to approximate center of cutout - mark that spot and use a rotary tool to cut out while in place. Usually results in a pretty good fitting cutout but is easy to miss something when trying to work fast.

They also leave a big mess for the finishing crew. Cuts are not always a good fit there are holes that need patching etc. These kind of things happen anyway but when they work as fast as they do there is a lot of it.

You really need to watch one of these crews sometime it is good entertainment. I have seen guys that use 5 gallon bucket as a step stool to reach ceiling. Sounds like something that may be expected to be seen right? Now let me tell you they can "walk" that bucket so make it a moving scaffold and don't have to get off of it to move it, all while holding a screw gun and driving screws into the ceiling.

 

[kwired]

How does it happen indeed. Many times the sheetrock hanger will argue when I say they covered a box, one that sticks in my mind was a kitchen with 6 cans, sheetrockers covered 3 and argued that the kitchen only had 3 cans, attic was accessible so it was easy to prove them wrong.

Another house only had 45 boxes, 12 were covered.

For a while I marked floor in front of box, too often by the time I came to trim finish floor was hiding my marks. I tried handing builder a can of orange spray paint thinking they'd be more aware of problems and help avert it, usually unused can still be at job when I went to find the buried boxes.

Luckily the economy crashed and I haven't had many new houses to wire. It's been a big relief.

I haven't done much new homes either recently, but have found that taking photos of the rough in is handy for finding things later. There was one job where in the family room they had a fireplace with custom cabinets and mantle surrounding it. Cabinet on one side we ran power for sound system and TV/satellite components because they were to be located inside this cabinet. The problem at finish time was the cabinet on other side did not have any electric outlets cut out and we couldn't remember if we even put any outlets there at rough in.

Luckily the HO had taken pictures of progress during rough in and we looked at them and determined there was a receptacle in the questioned area. I counted how many studs from the corner and had a good idea of the elevation. Carefully measured it and cut an inspection hole. Was right on target.

Ever since that job I try to take photos at rough in. Have used them a few times to help find something - or at least prove it is there.

 

[George Stolz]

This little guy is $40 and gets the job done for me. Almost as good as having xray vision.

 

[stevenje]

I would be interested in hearing any other techniques or methods that others use.

Sky

Back in the 70's I worked under the supervision of a crusty old journeyman who would "locate" the covered outlet boxes with his steel toed work boots. After a few "locates", it didn't take long for the drywaller's to gladly find any covered outlets for us. Sometimes I miss the old days.

 

[ptonsparky]

Accused the sheetrocker of covering us up and guaranteed that we had a box there...whoops.:ashamed:

 

[tkb]

This works better and they stop burying the boxes after you use it a few times.

 

[svh19044]

I have used my Ideal 61-956 multiple times for this, the contractors can never thank me enough. It is THAT GOOD in locating buried boxes for new work, as the wires aren't connected. It is pinpoint accurate, within an inch of the highest signal. If the wires are connected, you can follow the path and go on the high spot from there, poke with a tiny screw driver and feel for plastic.

Most of the time though, as you stated, you can see the drywall bulging and don't even need the tracer. And as noted, I always take pictures of jobs in rough in state.

 

[kwired]

This works better and they stop burying the boxes after you use it a few times.

That doesn't make any difference if the hanging crew hangs and is never on site again. It is not the taping crews fault the hangers did not make a cut out, yet they are the ones that have to fix it. If the hangers are penalized somehow for not making a cut out then it will start making a difference. Problem is they have already been paid before the missing cut out is discovered.

 

[George Stolz]

That doesn't make any difference if the hanging crew hangs and is never on site again.

Bingo. More headaches for everybody. I prefer to keep score and get free holes patched that I can't avoid making.