To find a water leak under a concrete floor is relatively straightforward, particularly if the leak has a high frequency or has a high volume. Concrete allows sound to pass through it fairly cleanly, this is due to there being little variation in the density or make up of the material. The only problem you may encounter is cavitation, this occurs where a larger cavity has been created by the escaping water, this causes acoustic disturbance and can interfere with readings.
Tracer gas can be particularly useful when trying to find a water leak under a concrete floor or slab. The molecular size of the gas is far smaller than the water, the escaping gas will easily permeate through the concrete and emerge at the surface where it can be detected using the ‘sniffer’ air sampling equipment.
The video below was made at a leak detection job we did in a restaurant. The whole floor area was concrete and the owner had no idea where to start to find the water leak. We had to find the leak, excavate, repair and make good the floor overnight in time for the next days trading
Call the leak detection specialists, Water Loss Solutions on 0141 473 4119