Take the 2-minute tour ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

I recently purchased my house and I am trying to find my internal valve to turn on my external faucet.

Unfortunately the previous owner put in a bathroom in over where the water line enters the house and it also covers the area where the external faucet enters the house.

I'm about to go making holes in the bathroom's drywall and ceiling to find the valve.

I would like some advice for tracing the water pipe so that I may avoid any obvious pitfalls and any advice for when I cut into the drywall for repairing it afterwards. (or maybe I'm going about this the wrong way)

share|improve this question
    
Some stud finders can detect wires and other objects in the wall. A metal detector might also work (assuming the pipe is not PEX, or other plastic material). –  Tester101 Jun 4 '12 at 20:28
add comment

4 Answers

up vote 3 down vote accepted

There is no way to trace the water pipe behind the walls with any certainty without using a hole in the wall. If none exists, you will have to make one (plus).

Make shallow cuts in the drywall. A vibrating tool with a circular blade will make nice, clean, sharp, easily patchable holes without cutting so deep as to risk cutting the pipes.

share|improve this answer
1  
there are ways of tracing pipes depending on the material the pipes are made of, such as location devices that connect to the pipes and send a signal throught them to be picked up –  UNECS Jun 5 '12 at 2:46
    
Thanks Greebo, hopefully the first hole is close enough to the valve so I can install an access panel on it. –  Biff MaGriff Jun 5 '12 at 17:27
    
@UNECS None of those will tell you where a valve is located. You still have to cut a hole and look to find that. –  The Evil Greebo Jun 6 '12 at 11:28
    
@theevilgreebo that is true but the question was how to trace water pipes –  UNECS Jun 6 '12 at 21:24
    
That was half the question: the whole question was how to trace water pipes with the goal of finding the shutoff valve.. –  The Evil Greebo Jun 7 '12 at 12:26
add comment

I was lucky and had limited access to the ceiling space that the pipe was running through by opening air ducts and pushing the vents up and out of the way. Using a webcam, a long usb cable and flashlight I managed to scope out the pipe in the space and trace it back to where it joined up to the main water line. Eventually I found the valve through pure chance. It was located inside of a wall stud and underneath a crossbeam rendering it all but invisible.

share|improve this answer
    
That's some pretty good detective work there, Biff. –  Chris Cudmore Jun 12 '12 at 14:34
add comment

If your water pipes are made of metal then you can use simple metal detector to detect route of your pipes. Simple :)

share|improve this answer
    
But so is electrical wires, nails, screws, metal studs, gas lines, HVAC ducts, etc. –  Steven Jun 5 '12 at 15:04
    
pipe will be continues and will have certain path not screws and studs. –  Rizstien Jun 5 '12 at 15:09
    
Copper isn't magnetic (try sticking a kitchen magnet to a pipe), so some metal detectors may not work. Also, home wiring is continuous. –  BMitch Jun 5 '12 at 15:20
    
I'd also guess that drywall screws placed 12" apart will look continuous to most metal detectors. –  gregmac Jun 5 '12 at 15:59
    
And as stated above - you still won't find your valves without actually looking. –  The Evil Greebo Jun 6 '12 at 11:29
add comment

If it's the hot water line, you can find them by running hot water for a few minutes and using an infrared camera. Alternatively, you can use a metal detector like Rizstien said. These options rely on equipment that you may not have, however, so perhaps you'd like to avoid spending $100+.

If you have to rely on cutting into the drywall, make sure you perform what is called a pumpkin cut, explained at 3:00 in this video. This prevents the removed piece of drywall from falling into the wall when you put it back in place and increases its long-term strength. If you cut straight through, it's harder to patch; you have to fasten a piece of wood spanning the gap to avoid these issues and screw / adhere it into place.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.