Water Mains & Underground Leak Detection
The pipe from the stop tap in the street to your kitchen is your responsibility, and when it leaks the water disappears into the ground. We find the exact spot, then dig one hole rather than a trench.
Water mains and underground leak detection, step by step
An underground supply pipe leak usually shows up as a high water bill, a meter that turns with everything off, low pressure, or a patch of ground or a section of driveway that never dries out. Because the pipe is buried, digging to find it means lifting block paving, breaking concrete or trenching a lawn on a guess. We do the finding first.
The acoustic ground microphone listens for the sound of water escaping under pressure through the ground or paving, and the reading peaks directly above the leak. On plastic pipe, which is quiet, and on long runs we use hydrogen tracer gas: the supply is isolated, the pipe is charged with the gas, and the detector is walked along the line of the pipe until it finds where the gas is surfacing. We check inspection chambers and the meter box as we go, because a leak at a joint in a chamber is a common find.
With the leak marked we excavate by hand in that one place, expose the pipe, repair or replace the failed section in MDPE with proper compression fittings, test it and reinstate the ground. If the pipe is old lead or steel and failing in more than one place, we tell you and quote for a new run.
Mains & underground in our own photos
From your first call to a leak you can see in the report
Call or WhatsApp with a few photos and a line about the symptoms. We ask a handful of questions, agree a fixed price and book the survey, usually for the same or the next day.
On arrival we pressure test the mains, hot water and heating, check the meter and test the escaping water, so we know what we are looking for before the detection starts.
Thermal imaging, the acoustic ground microphone and tracer gas are used as the pipework dictates until the leak is marked on the floor or wall.
You get a written report with readings, thermal images and photographs, ready for a trace and access claim. If you want the leak fixed, we open that one spot and repair it.
A report your insurer can act on
Most buildings insurance policies include trace and access cover for finding a hidden leak and making good the way in. Our report is written for that claim: what we tested, what we found, where it is, with photographs, thermal images and readings.
- Turn off the stop tap or the heating and stop topping up
- Photograph the damage, the boiler gauge and the meter
- Tell your insurer a leak is suspected and detection is being arranged
- Trace and access pays to find the leak and make good the access
Mains & underground: questions answered
How do I know the leak is on my supply pipe and not the water company's?
Your responsibility usually starts at the boundary stop tap. If the meter turns with every tap and appliance in the house off, the water is escaping between the meter and your taps, which is your side. We confirm this with a pressure test before any digging.
Can you find a leak under a block-paved driveway?
Yes. The acoustic microphone works through paving and the tracer gas comes up through the joints between blocks. Once the leak is marked we lift only the blocks over that spot and relay them afterwards.
Do you dig up the whole pipe run?
No. The point of locating the leak first is that we dig one hole at the marked spot. If the pipe turns out to be failing in several places we tell you, and a new run in MDPE is usually the better answer than repeated repairs.
What if the leak is under the house?
Supply pipes often come in under the kitchen or hallway floor. The same acoustic and tracer gas methods work through concrete and screed, and we open the floor in one place for the repair.
Will my water be off for long?
The supply is isolated while the pipe is charged with tracer gas and again during the repair, usually a few hours in total. We tell you before we turn anything off.
Related services
Think it is a mains & underground problem?
Call now and we will tell you straight away whether it needs a same-day visit. Or send a photo of the stain, the meter or the boiler gauge on WhatsApp.
07516 755 680