Leak Detection & Water Leak Repair in London
How to Find a Hidden Water Leak: The Signs to Look For
Stains on the Ceiling
Brown rings, bubbling paint or a ceiling that has started to sag. We test the pipes, the bath or shower waste and any tank above until we know which one it is.
Source TracedDamp That Will Not Dry
A patch on a wall or skirting that comes back however much you ventilate. We check whether supply pipes, wastes or drainage are feeding it before anyone calls it condensation.
Damp CheckedWarm Floors and Pressure Loss
A warm spot underfoot, a pressure gauge that keeps dropping or a cold-water pipe that never stops running. We narrow it down to one section of pipe under the floor.
Pipe Run IsolatedLeaks Under the Bath or Shower
Water shows downstairs only after someone has used the bath or shower. We test the waste, the seals and the supply one by one, so you fix the right thing.
Fixture TestingWeeping Valves and Joints
Slow drips from an isolation valve or a pipe joint that leave a tide mark over months. We find the joint and remake it so it holds.
Joint RepairA Meter That Keeps Turning
Your water meter moves with every tap off. That means water is escaping on the supply. We test it section by section until we find where.
Supply TestingLeak Detection in London Before Anything Is Opened Up
Water Leak Repair in London, With the Cause Explained
The Smallest Access Possible
We use bath panels, service hatches and small inspection openings wherever we can, rather than lifting whole floors or stripping walls.
Repairs Tested Under Pressure
Failed joints, corroded sections and split pipes are replaced with the right fittings, then pressure tested before anything is closed up.
A Clear Written Note
You get a plain-English note of the cause, the repair and anything else we spotted, which is useful for insurers and landlords.
From a Ceiling Stain to a Confirmed Repair
Tell Us What You Have Seen
Where the stain or damp is, when it appears and whether it gets worse after a bath or shower. A photo and a meter reading help us plan the tests.
Turn off the water if it is pouringWe Find It and Quote
We run the tests, confirm the source and give you a written price for the repair. Nothing is opened up without your agreement.
Findings explained firstWe Repair and Retest
The leak is repaired with minimal opening-up, the system is pressure tested and the area is left tidy. Covered for 12 months.
12-month guaranteeHow Much Does Leak Detection and Repair Cost?
When you need to know if there is a leak and roughly where it is.
- Visual and moisture checks
- Isolation and pressure tests
- Likely source identified
- Written findings and next steps
Our most common visit: leak found, repaired and tested in one go.
- Leak pinpointed
- Pipe or fitting repaired
- Final pressure test
- 12-month workmanship guarantee
For leaks under floors, in several places or in concealed pipework.
- Room-by-room investigation
- Planned access and making-good advice
- Parts listed in advance
- Written sign-off at the end
Written Price Before Work
The price covers the job we describe. No congestion, parking or travel extras are added later.
Leak Detection & Repair FAQs
How do you find a leak that I cannot see?
We work through it step by step. Isolation and pressure tests show which pipes are losing water, then moisture readings and a careful check along the pipe route narrow down the spot. We also rule out sealant and condensation, so you never pay for work that will not fix the problem.
Water is leaking through my ceiling from the flat above. What should I do?
Switch off the lights in that room if water is near them, catch the drips and tell your neighbour or managing agent straight away. The leak is usually in their bathroom or pipework. We can trace it from their flat, repair it and give you both a written note of the cause.
Is my ceiling stain definitely a plumbing leak?
Not always. Stains can come from pipes, bath or shower seals, roof defects or condensation. We test the plumbing first. If the evidence points to something outside our work, such as the roof, we tell you honestly so you can call the right trade instead.
My water bill has gone up. Could that be a leak?
It can be. Take a meter reading, leave every tap and appliance off for an hour, then read it again. If the meter has moved, water is escaping somewhere on the supply. Call us and we will test the pipework section by section to find it.
Who is responsible for a water meter leak?
Thames Water looks after the pipe up to your property boundary, and the supply pipe from the boundary into your home belongs to the owner. We test your side first, and if the leak is outside your boundary we tell you to report it to them.
Will you have to cut into my walls or floors?
Not always. We use bath panels, service hatches and small inspection openings where we can, and only open up where the evidence points to the leak. If bigger access is unavoidable, we explain why and how much making good you should expect before we start.
How much does leak detection cost?
A 2026 London price guide puts a leak behind a wall or under a floor at about £180 to £300 or more to repair, with tracing and making good often charged separately (Fantastic Services). We find the leak first, then give you a written quote before any repair starts.
Not Sure Where the Water Is Coming From?
Describe the stain, damp patch or drop in pressure. We will tell you the likely causes and the sensible first step, even if that step is not calling us out.
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