How we find supply pipe leaks
Nothing in the van finds a buried leak on its own. The work is a sequence that removes everything the leak is not, then puts two independent methods on the same spot before any ground is opened.
0333 567 2637Seven days a week, 7am to 9pm. Fixed price agreed before anyone travels.
Eight steps, in this order
Each one narrows the search, and each one is chosen because it fails differently from the one before it.
Survey the property and find the isolation points
Where the meter is, where the stop taps are, where the pipe is likely to run and what is on top of it. On an ADI job at Marlborough this took the first hour, because the property had no internal stop tap at all and the water had to be shut off from a valve hidden in an old gas box.
Prove which side of the wall the loss is on
The internal plumbing is isolated and pressure tested on its own. A section that holds is intact. At Grantham the inside of the house held 5.5 bar for thirty minutes, which moved the whole search outdoors before a paving slab was touched.
Where the internal stop tap has failed, this step is unavailable. That happened at Liverpool, and every remaining method took longer as a result.
Trace the line of the pipe
A leak cannot be listened for until the run is known, and buried pipe rarely follows the route anybody remembers. Tracing establishes where to put the microphone and, later, where not to dig.
Listen along the run
A ground microphone is moved along the line in steps, listening for water forcing its way out under pressure. The loudest point is the first candidate, and on a paved surface that is often enough to narrow the search to a couple of metres.
Correlate where the run is long
Two sensors are clamped to the pipe and the delay between the same sound reaching each one is converted into a distance. On a long, shared or inaccessible run this replaces walking the whole length.
Confirm with tracer gas
The pipe is drained and filled with a hydrogen and nitrogen mix, which is lighter than air and rises through soil, sand and block paving. A detector at the surface reads directly above the fault. At Grantham the gas and the acoustic trace agreed on the same spot on the driveway, which is what turns a survey into an excavation the size of a paving slab.
Open up, and repair where the job allows
Excavation happens where two methods agree. The engineers are plumbers as well as leak detection specialists, so a reachable fault can be repaired on the same visit, quoted before it starts and covered by a workmanship guarantee.
Test, report and leave it safe
The repair is pressure tested, the excavation is backfilled and made safe, and the report records the fault, the location, the methods and the evidence, with photographs. That document is what a leak allowance claim and a trace and access claim are both assessed on.
Why two methods rather than one
Every instrument on this site has a blind spot, and each one has a different blind spot. Sound is defeated by soft deep soil and by traffic. Gas needs the pipe emptied. Thermal imaging reads sun on a driveway as readily as it reads a leak.
Two methods that fail differently, agreeing on the same square metre, is a far stronger result than one method insisting. It is also the difference between a hole and a trench.
Questions about the visit
Will you need to dig up my drive?
We use equipment such as acoustic listening and tracer gas to narrow the search before excavation. Some access may still be needed to confirm the location and reach the pipe for repair. We cannot promise that every investigation will be free of digging or damage.
Guidance: ADI water mains service; ADI service FAQs.
How long should I allow for the visit?
We allocate a full day to finding the leak. We aim to repair it during the visit where access, materials and time allow.
Guidance: ADI service FAQs.
What should I arrange before the visit?
Arrange access to the property, meter and stop taps, and parking nearby. Tell us about shared supplies or faulty valves when booking. Have any water company notice and recent readings ready.
You do not have to remain on site if access is arranged, but you need to be available by phone during the appointment.
Guidance: ADI full booking terms; ADI service FAQs.
Will I receive a report?
Yes. ADI provides a written report of the investigation to support an insurance claim, released after payment. You can also ask your water company what documents it needs for a leak allowance. The insurer or supplier decides whether the claim meets its conditions.
Guidance: ADI service FAQs; Thames Water leak allowance conditions.
Tell us what the meter is doing
Describe what you have seen and we will tell you whether it sounds like the supply pipe, what the visit involves and what it costs before anyone travels.
The office team speak to every customer before an engineer is booked, and the engineer who attends is the one who writes the report.
Seven days a week, 7am to 9pm
England, Scotland and Wales. £5 million public liability insurance.