Underground water leak detection in Sussex, Surrey & London
The supply pipe running from the water main to your stop tap is your responsibility, and it is usually the least accessible pipe you own. A leak on it can run for years, showing up only as an unexplained water bill, a patch of grass that stays green through a drought, or a driveway that never dries.
Digging to find it is the expensive way round. Acoustic correlation lets us listen to the pipe from both ends and calculate the distance to the noise, and pipe tracing tells us exactly where the run goes and how deep it sits. That turns a trench across the whole garden into a hole you could cover with a bin lid.
Our approach
How we find underground water leaks
These are the methods we would normally work through on this kind of job, in this order, stopping as soon as the evidence agrees on one point.
- 1
Acoustic leak correlation
A pressurised leak makes a continuous noise that travels along the pipe wall. Sensors placed either side of a suspected run measure the tiny difference in arrival time between them, and the correlator converts that into a distance. On a mains supply pipe this routinely gets us to within a foot of the fault.
- 2
Pipe and cable tracing
Knowing where a pipe actually runs, as opposed to where the drawings say it runs, prevents the two most expensive mistakes on any leak job: digging in the wrong place, and putting a spade through a live service. We mark the route on the surface and record the depth.
- 3
Tracer gas testing
Hydrogen is the smallest molecule there is, so it finds its way out of a crack far too small to see and rises straight up through concrete, screed and soil. We sweep the surface with a sensitive detector and the reading spikes directly over the breach. The gas mix is non-toxic, non-flammable at the concentration used, and leaves nothing behind.
- 4
Thermal imaging camera survey
Water moving where it should not changes the temperature of everything it touches. A thermal camera renders those differences as an image, so a leak under a solid floor shows up as a shape long before it shows up as a stain. It is completely passive: nothing is drilled, lifted or cut to take the reading.
What happens
Trace, access, repair, prove
The same four stages on every job, whether it is a weeping joint or a mains supply pipe under a driveway.
- 1
Trace
Non-invasive survey of the whole affected area. We rule systems out as well as in, because knowing what is not leaking is half the evidence.
- 2
Access
One opening, in the right place, as small as the job allows. Usually a borescope hole first, and a larger opening only if the repair needs it.
- 3
Repair
The fault fixed on the same visit wherever it can be, guaranteed for 12 months. Anything larger is quoted at a fixed price before we start.
- 4
Prove
The circuit re-pressurised and held, moisture readings taken again, and the whole job written up with dated photographs and calibrated readings.
Pricing
Published rates, no call-out fee
Charged by the half hour with a half an hour minimum, and no premium for an emergency. All prices exclude VAT at 20%.
- Weekdays7am – 6pm, Monday to Friday£54.00+ VAT
- Evenings & weekends6pm – 9pm weekdays, plus all day Saturday and Sunday£69.75+ VAT
- Late night9pm – 7am, every day£90.00+ VAT
Questions
Underground water leak detection: your questions
Is the leak my responsibility or the water company's?
As a rule, the supply pipe from the boundary stop tap into your property is yours, and everything on the street side belongs to the water company. Our report identifies which side of that boundary the fault sits on, which matters because many water companies will repair a first leak on a customer supply pipe free of charge.
How accurate is acoustic leak detection?
On a metal or plastic supply pipe under normal mains pressure we would expect to be within about a foot. Accuracy drops on very deep pipes, in extremely noisy locations, or where the leak has no pressure behind it, and in those cases we bring in tracer gas.
Can you find a leak under a concrete driveway?
Yes. Acoustic equipment works through concrete and tarmac perfectly well, and tracer gas will rise through both. Finding the precise point is what makes it viable to core a small hole rather than break out the whole slab.
Related services
- Pipe location and mappingMapping where pipes and services actually run, and how deep, before anyone excavates or drills.
- Water leak detectionThe core survey: we find the exact source of any escape of water in your property without lifting floors or opening walls on a guess.
- Leak repairFind and fix in one visit wherever possible, with the repair pressure tested and proved before we leave.
Underground water leak detection near you
We cover 74 towns, cities and boroughs across Sussex, Surrey and London.
Sussex
Need underground water leak detection?
Call 01273 123 5050 for free advice, or book a survey online. No call-out fee, and we will tell you honestly if you do not need us.