Leak From the Flat Above: Source, Evidence and Responsibility
Stains on a ceiling tell you water is arriving, not where it comes from. Before anyone argues about who pays, somebody has to find the pipe.
In converted houses and purpose-built blocks across London, a leak from the flat above is one of the most common and most contested problems we investigate. The water may come from a bath or shower seal, a concealed pipe in a floor or duct, a pinhole in copper heating pipework, a washing machine connection, a toilet pan connector, or a communal pipe such as a soil stack or rising main that is nobody’s fault and everybody’s problem. Each has a different route to repair and a different answer to the question of who pays.
How we investigate a ceiling leak
- Moisture mapping and thermal imaging of the ceiling and walls below, to find the true wet area and the direction it is spreading from
- Inspection of the flat above where access is granted: bathrooms, kitchen, heating and any visible pipework
- Controlled water tests on baths, showers, basins, toilets and appliances, one at a time, to see which produces the leak
- Pressure tests of the heating and hot and cold supplies, isolating circuits in turn
- Dye testing where several fittings share a route
- Checks on communal stacks, rising mains and roof outlets where the pattern points away from the flat above
- A written report with the source, the evidence and whether the pipe is demised to a flat or part of the communal installation
Who pays for a leak between flats
Usually the lease decides. Pipes serving only one flat are normally demised to that flat; shared stacks and risers are normally the freeholder’s or management company’s. Block insurance often covers the resulting damage, and trace and access cover can pay for the cost of finding the leak and making good the access. What insurers and managing agents need is an independent record of where the water came from, which is what our report provides. See trace and access and insurance leak investigations.
Common sources we find
- Failed silicone or grout around a bath or shower tray, leaking only when in use
- Shower trays with a cracked waste or failed upstand
- Pinhole corrosion in copper heating pipes under floors
- Push-fit or compression joints behind kitchen units
- Toilet pan connectors and cistern overflows
- Washing machine and dishwasher hoses
- Communal soil stacks, rising mains and roof outlets
- Condensation on cold pipework misread as a leak
Access and neighbours
We often attend on behalf of the flat below, the flat above, the freeholder or the managing agent. We are courteous, we explain what we are doing, and we test fittings without damage. Where access to the flat above is refused, the report records what could be established from below and what the managing agent needs to arrange. If you have home emergency cover, check whether it includes locating leaks; many policies cover only the repair once found.
We investigate across Greater London and Surrey. See areas we cover.
Frequently Asked Questions
The leak only happens sometimes. Can you still find it?
Yes. Intermittent leaks usually track to a fitting that is used intermittently: a bath, a shower, an appliance. Controlled water tests reproduce the leak on the day.
Do you need to open the ceiling?
Usually not to locate the source. A small inspection opening is sometimes the quickest route to confirming a concealed pipe, and we agree it with you first.
Is the leak my upstairs neighbour’s responsibility?
It depends on which pipe or fitting is leaking and what the lease says. Our report identifies the source so that question can be answered properly.
Will my insurer accept your report?
Our reports are written for insurers and managing agents: source, evidence, photographs, readings and a repair scope. They are used routinely in escape-of-water and trace and access claims.
Do you repair the leak?
No. DML locates and reports. The repair is quoted separately by our team or any plumber, against the exact location in our report.
Related services
- Leak detection
- Trace and access
- For property managers
- Escape of water investigations
- Central heating leaks
Related reading: Ceiling leak from the flat above: who pays and what to do · Mould after a leak: why it appears weeks later
Water coming through the ceiling?
Independent leak investigations in flats and blocks across London and Surrey.
Last reviewed: 23 October 2026. Independent investigation and written reports. Repairs are quoted separately.