A leak on the mains, found without digging up the drive.
When the leak is on the incoming mains, the trail usually runs under a driveway, a path or a garden. We locate it by listening, not by excavating, pinpointing the escape so one section is lifted, not the whole run.
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Signs your external supply is leaking.
Mains leaks often run for months unseen because the water disappears straight into the ground. These are the clues that something is escaping before it reaches your stop tap.
A jump in your water bill
A metered bill climbing with no change in usage is the classic mains-leak signature, water lost before it ever reaches a tap.
Damp patches on the drive
Persistently wet paving, a patch that never dries, or unusually lush grass along the supply route can mark the leak below.
Low pressure at the tap
Weak flow throughout the house, especially if it has dropped gradually, can mean water is escaping the supply pipe underground.
The meter spins with everything off
Turn off every tap and appliance: if the meter still ticks over, water is being lost somewhere on your side of it.
Ground movement or sinkage
A slowly sinking spot in a drive, path or lawn can be soil washing away around a leaking buried pipe.
Water in the boundary box
Standing water in the meter or stop-tap chamber by the boundary often points to a fitting or pipe failing right there.
Located by sound, not by spade.
A pressurised mains leak makes a noise that travels along the pipe. We measure that sound from two points and let the maths tell us where the leak is to within a fraction of a metre.
Confirm the loss
A meter test proves water is being lost on the supply, and isolating sections tells us it’s the external mains rather than internal plumbing.
Trace the route
We establish where the supply pipe runs between the boundary and the house, under the drive, the path or the garden.
Acoustic correlation
Sensors at two access points measure the leak sound; correlating the time difference pinpoints the escape along the run, with tracer gas to confirm where needed.
Marked & reported
The spot is marked on the surface and written up within 48 hours, so one section is opened for repair, not the entire driveway.
One opening, not the whole runThe whole point is not digging blind.
Excavating a driveway on guesswork is expensive and rarely lands on the leak first time. Locating it precisely first means the groundworker lifts one section, fixes the fault, and reinstates a small area not a whole expanse of paving.
- Pinpointed before excavation the dig is targeted, not exploratory.
- Block paving, tarmac or lawn we work across all common surfaces.
- Boundary to building the full private supply run, both ends checked.
The gentleman that came today to find my leak and fix it were very friendly and explained everything they were going to do. They showed me where the issue was and fixed it in a timely fashion. Would h…
I called Leapfrog leak detection to source a leak which was causing me massive problems. Stuart identified the source of the leak very quickly and used non invasive methods which was a godsend. I can’…
Thanks again for coming to find our leak. Found it, solved it. Polite, kept us informed, good communicator, highly recommended.
External mains leak questions, answered.
How can I confirm that my incoming mains is leaking?
Turn off taps and water-using appliances and check whether the meter still moves. We then carry out a controlled meter and isolation test to prove whether water is being lost on the external supply rather than inside the property.
Is the leak the water company's responsibility or mine?
A leak between the boundary meter or stop tap and the building is usually on the private supply, while a fault on the network side should be reported to the water company. The exact responsibility depends on the pipe layout and ownership, so locating the loss first is important.
Can you find a mains leak without digging up the driveway?
Yes. We trace the pipe route and listen for the sound produced by water escaping under pressure. Acoustic correlation compares readings from two access points, with tracer gas used where needed, so the surface is not opened simply to search.
Can you work beneath block paving, tarmac, concrete or a lawn?
Yes. The detection survey is carried out from the surface across common driveway, path and garden finishes. Once the position is marked, a groundworker can target the smallest practical area for excavation and reinstatement.
How accurately can you locate an underground mains leak?
In suitable conditions, we typically locate the leak to around ±0.3 metres. Pipe material, depth, background noise and available access points can affect the result, so we cross-check the acoustic location and use tracer gas where appropriate.
How long does an external mains survey take and what does it cost?
External mains surveys start from £450 for a four-hour minimum visit. That is often enough to confirm the loss, trace the route, correlate the leak sound and mark the location. We agree the price before attending.
Do you excavate and repair the supply pipe?
The detection visit is designed to locate the fault before excavation. We mark the spot and provide a repair scope so your groundworker, plumber or insurer’s contractor can open one targeted section and repair the pipe.
Can I claim the detection cost on insurance, and where do you cover?
Where a mains leak has caused insured damage, trace-and-access costs may be recoverable, but this depends on your policy and insurer. We provide an insurance-ready report and cover Hertfordshire, Essex, London and surrounding counties.
A leak under the drive found from the surface, before a single slab moves.
Clear pricing, often insurance-recoverable.
External mains surveys start from £450 for a four-hour minimum visit. Where the leak has caused damage, the detection is frequently recoverable through your buildings insurance under trace & access.
Across Hertfordshire, Essex & London.
Based in Hertfordshire and on the road across London and surrounding counties. Most surveys are booked within two working days.
Water bill climbing for no reason?
Tell us what your meter’s doing and we’ll come back the same working day with an honest answer and a clear price and find it without digging blind.