Internal Cold Mains Leak Detection in Southampton

Symptoms

An initial meter test confirmed a leak rate of approximately 10 litres per hour, and incoming water pressure was measured at 7.0 bar — well above typical domestic levels. The spread of damage across multiple surfaces made pinpointing the source complex, and internal leak detection was required to trace the leak to its precise origin without unnecessary structural disruption.

Methods Used

Thermal imaging of the wall confirmed pipes were embedded within the plaster rather than running through a cavity. This ruled out straightforward access and made internal leak detection through targeted, informed exposure the only viable approach.

Ceramic tiles were removed and a section of very thick plaster was broken open to expose the pipe run. The leaking pipe was found positioned behind both the shower and basin waste pipes within the wall, requiring those waste pipes to be cut out before the leak could be accessed directly.

Investigation Process

1. 1
   Initial inspection

   The leak area was inspected on arrival, with water damage noted across the living room ceiling, cloakroom ceiling and wall, stairwell wall and woodwork, and the en-suite shower room wall.

2. 2
   Meter and pressure test

   An initial meter test confirmed a leak rate of approximately 10 litres per hour, and incoming water pressure was recorded at 7.0 bar.

3. 3
   Cold feed isolation

   The cold feed to the first floor was isolated using a lever valve to allow tracer gas to be safely introduced into the system.

4. 4
   Tracer gas introduction

   Hydrogen tracer gas was introduced into the system at 7.0 bar. Both an acoustic signal and a tracer gas reading were detected beneath the en-suite basin.

5. 5
   Living room ceiling opened

   A small hole was made in the living room ceiling to inspect the void, but no pipes were found in that space.

6. 6
   Thermal imaging of wall

   Thermal imaging confirmed that pipes were embedded within the en-suite wall rather than running through an accessible void.

7. 7
   Wall opened and leak exposed

   Ceramic tiles were removed and a section of very thick plaster was broken open, exposing the pipe run within the wall.

8. 8
   Waste pipes cut out

   The shower and basin waste pipes were cut out to gain access to the leaking pipe, which was positioned directly behind them within the wall.

9. 9
   Leak located

   A leak was confirmed on a 15mm copper pipe embedded within the en-suite wall behind the shower and basin waste pipes.

Result & Outcome

With the leak pinpointed and the pipe now accessible, the repair can be carried out directly to the 15mm copper pipe. The damage to the living room ceiling, cloakroom, stairwell, and en-suite wall can now be addressed with confidence that the source has been found and will not continue to cause further deterioration.