Questions about finding hidden leaks

It is the investigation of water leaks hidden beneath floors, behind walls or on buried pipes. Engineers check accessible fittings and use suitable tests such as moisture mapping, thermal imaging, pressure testing, acoustic listening and tracer gas to narrow down the source.

Many checks can be made from the surface or at accessible fittings. The aim is to reduce exploratory opening, but an inspection hole may still be needed and repairing a concealed pipe usually requires access. The engineer should discuss proposed access before work begins.

Plastic pipe can be investigated, although it carries leak noise less well than many metal pipes. Testing individual sections, tracing the route and using tracer gas or other suitable methods can help. Access and the construction around the pipe affect what is possible.

It can, but visible radiator valves, boiler components and a pressure relief discharge can also cause pressure loss. Those checks help decide whether the concealed heating pipework needs testing. Pressure loss on its own does not establish the location.

There is no single depth limit across all methods. Pipe depth, floor construction, access, pressure and material affect the investigation. An engineer combines suitable tests and explains the limitations at your property rather than promising a fixed accuracy.

Sensitive microphones pick up the noise of water escaping from a pressurised pipe. Comparing readings along the pipe route can help narrow down a leak. Quiet leaks, plastic pipes and background noise can make another method more useful.

Moisture can spread away from a leak, sound can travel along pipes, and tracer gas can emerge through an easier path in the floor. Comparing test results helps the engineer interpret those clues and select an area to investigate.

Describe damp patches, meter movement, pressure loss or sounds of water, and when they occur. Mention the floor finish, known pipe routes and any previous work. Keep meter readings or photographs if you already have them; the office can advise on preparation.

Layered floors, inaccessible pipework, deep buried runs, several adjacent pipes and very slow leaks can complicate the survey. Background noise affects listening, while voids can allow water or test gas to travel away from the defect. Further access or testing may be needed.

ADI Leak Detection’s engineers work across England, Scotland and Wales. Call the office with your postcode to discuss a visit.

On many of the real jobs shown here, ADI opened the identified area, repaired the damaged pipe and tested it afterwards. What can be done depends on the pipe, access and the work required. Discuss repair and reinstatement when you call.

ADI provides a report of the tests and findings, with photographs, which you can share with your insurer. Check any requirements with your insurer before authorising work; a report does not establish that your policy covers the cost.

The survey findings can help you discuss the leak with the water company. Ownership and responsibility depend on the supply arrangement; the boundary alone does not resolve every case. Ask the water company to confirm responsibility where needed.