Pressurised water leaving a small hole in a copper or steel water pipe creates a distinctive sound, a hiss between roughly 200Hz and 4kHz, that travels along the pipework and through surrounding building materials. Trained operators using calibrated electronic listening equipment can detect this sound, isolate it from background noise, and locate the leak with remarkable precision.
Acoustic leak detection is particularly effective on metallic supply pipework, copper hot/cold lines, lead supply mains, steel risers, where the sound carries efficiently. We use SewerIn Aquaphon A200 ground microphones, Sebakmt T8 contact sensors and Vivax Metrotech correlators, equipment shared with Thames Water and other UK water authorities for mains-leak surveys.
Where this service applies
- Underground supply pipe leaks (lead, MDPE, copper)
- Buried mains supply between Thames Water stop-tap and property
- Hot & cold water leaks under solid screed floors
- Sub-floor pipe failures in flats above living spaces
- Riser leaks in mansion blocks and apartment buildings
- Concealed leaks where thermal imaging is not conclusive (well-insulated walls)
- Verification of suspected leak locations identified by other methods
- Insurance trace-and-access claims
How we deliver
No surprises, no upselling. The exact path every job follows.
- 1
Pressure-test isolation
Hot vs cold, ground floor vs upstairs, isolated to identify which circuit is leaking. - 2
Background noise survey
Calibrate listening equipment to filter out road noise, pumps, refrigerators. - 3
Surface contact survey
Listening stick on every accessible pipe, valve and connection. - 4
Ground microphone walk
Where buried pipework is suspected, ground microphones used at 1m intervals. - 5
Correlation analysis
For longer pipe runs, two synchronised sensors used to triangulate the leak source mathematically. - 6
Insurance-grade written report
Located leak position marked on plan. Access cuts recommended.