Finding Leak under concrete floor

[RoryC]

Hi all,

Is there a way of finding a leak under a concrete floor without digging it up? Is it best to use the visual method of dampness on the concrete or should I go more high tech and hire someone to detect it? Either way the floor has to come up I reckon.

Also, my kitchen extension has started to leak where it joins the original house wall. The lead flashing seems to be joined into the main house wall although I have noticed the cement covering the flashing is cracked.

Cheers, Rory.

[Stuart Noble]

You can sometimes hear a leak if you put your ear to the rising main, preferably in the dead of night. If you have a stopcock in the road, turn that off to get the sound of no water running to compare it with. Often in older houses they no longer work, so the water board will fit you a nice new plastic one for free. In any case you should be able to run a new pipe without digging the floor up if you can trace where it enters the house

Maybe the flashing isn't wide enough, or not far enough into the brick. Not sure of the current standard but rain certainly blows under it if it's too narrow.