Homeowners — London
Leak detection — no find, no fee
Hidden water leaks tracked and found across all 33 London boroughs using thermal imaging and acoustic technology. If we cannot find the leak, you do not pay.
Leak detection London homeowners
About this service
Why hidden leaks are particularly damaging in London homes
London property values are among the highest in the UK, which means even modest water ingress behind a wall or under a floor can trigger disproportionately expensive remediation. Structural drying after a hidden leak has been left to saturate a partition wall or timber joist can run into thousands of pounds — costs that dwarf the price of early detection. More critically, persistent moisture behind plaster creates the conditions for black mould growth, which carries genuine respiratory health risks, particularly for children and anyone with asthma.
Our engineers use professional-grade thermal imaging cameras to identify the temperature differentials created when cold or hot water escapes a pressurised pipe. Water conducts heat differently from the surrounding building fabric, creating a measurable signature that appears clearly on a thermal display — through a plastered wall, beneath a tiled bathroom floor, or above a plasterboard ceiling. This approach is entirely non-invasive: there is no drilling, no lifting of tiles, and no exploratory chasing of plaster during the detection phase itself.
For leaks under solid floors or behind dense brickwork where thermal cameras are less effective, we deploy acoustic listening equipment. These highly sensitive microphones detect the unique sound frequency of water escaping a pressurised pipe — a frequency distinct from background noise and audible even through 150mm of concrete or two layers of brick. Together, thermal and acoustic methods allow us to hand you a precise leak location before a single tile is lifted or a single wall opened.
Common hidden leak sources in London homes
In our experience across London's housing stock, the most frequent culprits are: shower trays where the silicone seal has failed at the tray-to-wall junction (water tracks horizontally before appearing as a damp patch well away from the shower); bath waste connections that have cracked or corroded inside an enclosed panel; push-fit or compression pipe joints hidden inside stud walls that have vibrated loose over years; and mains cold-water supply pipes running under the concrete ground floors common in 1960s–1980s London properties.
Mains water supply leaks deserve particular attention. If your water meter continues to tick when every appliance, tap and cistern in the property is turned off, water is escaping somewhere between Thames Water's network and your stopcock — typically in the underground supply pipe that crosses your front garden or runs under the path. We locate these with correlating acoustic equipment and can arrange the repair. Left unaddressed, a mains supply leak will inflate your Thames Water bill significantly and can cause subsidence in clay-heavy London soils.
If you intend to make an insurance claim — whether for escape of water or associated subsidence — our engineers produce a full written trace and access report. This includes scaled photographs of the affected area, a leak location diagram with measurements, the detection methodology used, and a recommended repair scope. This format is accepted by all major UK home insurers and loss adjusters as part of an escape of water claim, removing any friction from your claim process. Our team is Gas Safe registered and carries full public liability insurance, so your insurer's surveyor will have no grounds to query our credentials.
Survey pricing
£200 – £450
Full leak detection survey covering thermal imaging scan, acoustic detection, moisture mapping, written report and leak location diagram. Clear fixed price quoted before we start — no hidden extras. Same-day attendance available for urgent cases across all 33 London boroughs.
180+ verified reviews
60 reviews on Checkatrade and 120 on MyBuilder — independently verified homeowner feedback from across London.
All 33 London boroughs
From Enfield to Croydon, Hillingdon to Havering — we cover every borough with the same team and the same standards.
Gas Safe registered
Our engineers are Gas Safe registered and fully insured, giving you the credentials your insurer needs on any escape of water claim.
Signs you may have a hidden leak
Could you have a water leak?
Unexplained damp patches on walls or ceilings
Moisture appearing through plaster or paint without an obvious cause
Rising water bills
Increased consumption with no change in usage habits
Sound of running water when everything is off
A faint hissing or dripping sound in walls or under floors
Warm patch on the floor
Hot water pipe leaking under a solid floor — detectable with thermal imaging
Recurring drop in boiler pressure
Central heating system losing pressure regularly indicates a leak in the circuit
Mould in unexpected locations
Mould growing on internal walls away from bathrooms or kitchens
Common questions
Leak detection: frequently asked
What is no find no fee leak detection?
No find no fee means if our engineer cannot locate the leak, you do not pay for the detection visit. You only pay when the leak is found. This protects you from paying for an unsuccessful search.
How do you find hidden water leaks?
We use a combination of thermal imaging cameras (which detect temperature differences caused by leaking water), acoustic listening equipment (which picks up the sound of escaping water through walls and floors), and moisture meters. This allows us to pinpoint leaks without unnecessary damage to floors or walls.
What are the signs of a hidden water leak?
Unexplained damp patches on walls, floors or ceilings; rising water bills with no change in usage; the sound of running water when nothing is turned on; warm patches on the floor (suggesting an underfloor hot water leak); mould in unexpected locations; or a drop in boiler pressure that recurs regularly.
How much does leak detection cost in London?
Leak detection visits in London typically cost £200–£450 depending on the type of leak suspected and the area to be searched. Under our no find no fee policy, if we cannot locate the leak you do not pay for the detection.