Wednesday, March 12, 2014

locate-leak-in-concrete-slab



I believe I have a leak in my copper piping under my concrete slab. How do I locate the leak .

If the floor surface is or can be exposed, it will usually show up on an IR scan.

Are you on city water with a water meter?, and if so can you see the dial spin without any water running-dripping-leaking anywhere else?, or can you place a metal glass or other stethoscope to a water line and hear it?
How have you determined there is a leak?

Yes I am on city water and the meter is spinning while everything is turned off in the house. I used a stethoscope against the pipe and can here it running.

I've seen leaks that sounded like they were underneath a water heater platform from resonant vibrations actually be 30 feet away outside in the driveway. Keeping that in mind listening to the pipes usually doesn't work.
The first thing you need to do is isolate it. A lot of plumbers will install a main shut-off inside your house. (Note it's not the valve directly on top of your water heater but could be in that closet)
If you have a shut-off valve inside your house turn it off and if the water meter is still spinning outside that means your leak is between the valve and the meter. If the valve is in your garage chances are the water line goes straight out the garage then curves toward the meter. Following that logic, place your stethoscope on the ground and listen for a spraying sound accompanied by the sound of rocks hitting each other. Kind of like what you would hear if you were squirting a garden hose at the rocks in the bottom of a fish tank. This is the sound of a slab leak or as some plumber call it the sound of money. A lot of plumbers will run plastic piping up to the driveway then transition to copper with some sort of coupling. There's a good chance that's where your leak is.
If you don't have a shut-off valve inside your house it can be complicated. You may have to call a leak detector which will charge you around a $150 min. so be ready for that. Other wise I would make sure your house is really quiet and take the stethoscope in all the rooms where there plumbing fixtures and listen to the floor and compare the sounds you hear in different spots. It will get louder the closer you get.

Hi, Most slab leaks are hot water.Take your shoes off and walk around the house and feel for a warm slab. If that fails try the rest of the other things.
Good Luck Woodbutcher

Originally Posted by Woodbutcher
Hi, Most slab leaks are hot water.Take your shoes off and walk around the house and feel for a warm slab. If that fails try the rest of the other things.
Good Luck Woodbutcher
Or look for the spot in the middle of the floor where the cat is always sleeping.

As one said you need to isolate the water circuit that is leaking. It is usually a waste of time repairing a leak in a failing water line under a slap as it will just fail again later. If you can go overhead and replace the whole line is better. I replace a hot water line
that was under the slab with a line overhead in the attic with a cpvc line a couple years ago that kept me from having to use a torch in the attic. It worked prefectly for me and required me only to solder the adapter to a copper line on both ends the rest was glued cpvc.
If you use CPVC make sure you use cleaner and the proper glue for it.






Tags: locate, leak, concrete, slab, water line, your house, inside your, inside your house, water meter, around house, around house feel, around house feel warm, around house feel warm slab, city water