Two leaks under tiled floors found by listening in Neston

Signs of the leak in Neston

The hot water cylinder was making a noise, which stopped only when the water softener was isolated. There was no visible sign of a leak, and the locations of the inside and outside stop cocks were not known.

How acoustic equipment found it

After the hot feed pipework failed a pressure test, the engineer scanned the floors with a ground microphone and picked up an anomaly under the corridor tiles, where the first leak was found. When the pipework failed again after that repair, further listening picked up a second anomaly under the bathroom tiles, where the second leak was found.

The investigation, step by step

1. 01Traced the unknown stop cock positions and used the water softener as the isolation point.
2. 02Passed an endoscope camera behind the bathroom tiles to follow the blue plastic pipe and check for isolation valves; none were found.
3. 03Pressure tested the hot feed pipework, which failed.
4. 04Listened across the floors and picked up an anomaly under the corridor tiles.
5. 05Opened the corridor floor, found a very wet plywood box around the pipes, and replaced a leaking 15mm copper pipe.
6. 06Retested; it failed again, and further listening picked up an anomaly under the bathroom tiles.
7. 07Opened the bathroom floor and replaced a leaking 22mm soldered copper tee.
8. 08Final test at 3 bar for 20 minutes passed.

What was found

Found

Two leaks: a leaking 15mm copper pipe in a plywood box under the corridor floor, and a leaking 22mm soldered copper tee under the bathroom floor.

Repair

Both leaks were repaired with new copper pipe and fittings, and the pipework passed a test at 3 bar for 20 minutes.

Recommended afterwards

Leave the opened floors uncovered until the screed and subfloor have dried out. Confirm the outside stop cock position with the water company, and have the inside stop cock sorted out once it is found.

Worth knowing

The final test showed no further leaks at the time of testing.