Who is liable for a water leak from an upstairs flat
In the UK, the person who owns the pipe, appliance or fitting that leaked is usually the one who has to get it repaired. In a block of leasehold flats, the lease decides whose that is. Pipes that serve one flat normally belong to that flat. Shared pipes and the structure between floors normally sit with the freeholder or the management company. Paying for the damage in your flat is a separate question.
Unless someone was careless, each household normally claims on its own insurance. Careless means something like a bath left running, or a drip the neighbour was told about and ignored. Where a pipe simply failed, the building's policy usually covers ceilings, floors and other parts of the structure, and your contents policy covers your belongings. Leases and policies differ, so treat this as general information, not legal advice.
First steps today
Deal with safety and the source before anything else. If water is anywhere near a light or a socket, turn that circuit off at the fuse box and keep it off until an electrician has looked at it. Then go upstairs and ask your neighbour to close their stop tap. In a flat it may be in the kitchen, an airing cupboard or a cupboard off the communal hallway.
If nobody answers upstairs and water keeps coming, ring the landlord, the letting agent or the managing agent, who may hold keys or know where the flat's stop tap is. Keep a short written record of who you spoke to and when. It saves arguments later, and an insurer may ask to see it.
Buckets under the drips, furniture and electricals moved away
Photographs of the ceiling and damage before you clear up
A note of when you first saw the water
The landlord, letting agent or managing agent told
Your own insurer told early, before any repairs
The leak is not always in the flat directly above
Water rarely drops straight down. In a converted Victorian house, the kind found in older parts of Norwich, Cambridge and Southend, it can run along a timber joist for a metre or two before it shows. In a purpose-built block it can track across the top of a concrete floor or follow a pipe through the wall. The stain marks where the water came out, not where it started.
So the source could be the flat diagonally above, a flat two floors up, or the flat next door on your own level where pipes run through a shared wall. It could be a shared pipe in a riser, the boxed-in shaft that carries pipes up through the building. If the patch only grows after heavy rain, the outside of the building is the likelier cause, and a builder is the person to call.
Who usually arranges the investigation
There is no single rule, and in practice it is often whoever moves first. If your neighbour accepts the leak is probably theirs, they or their landlord usually book the visit. If nobody knows whose pipe it is, or it could be a shared one, the managing agent or freeholder often arranges it. Some insurers want a say before anyone is sent in, so ring yours first.
The booking can come from the owner upstairs, the household below, a landlord or an agent. When you ring, tell us whose flat it is and who is paying, and mention any pipework that may run to or under a neighbour's flat. Where the person paying cannot be at the property, we may ask them to pay up front, before the booking is confirmed.
Why concrete floors mean testing from upstairs
Many purpose-built blocks have concrete floors between flats. The pipes feeding the bathroom above usually run in that floor or along the walls upstairs, so cutting into your ceiling tends to show nothing but wet concrete. Instead, we take moisture readings below to map how far the damp has spread and which way it is coming from, then do the real searching in the flat above.
Two kinds of leak behave differently. A supply pipe under pressure leaks all the time, so a pressure test on the flat's pipework, with its water shut off, shows the pressure falling away. A shower tray seal or a bath waste, the pipe under the plughole, only leaks when someone uses it, so each fitting is run in turn while someone watches below. Thermal imaging follows hot pipes under the tiles, and we only mark the floor once two different tests agree.
Insurance and the report
Before the visit, find out which policies are involved. The building's policy is usually arranged by the freeholder or managing agent, so a claim on it tends to go through them: ask for the policy details. Check whether it includes trace and access cover, meaning cover for tracing a leak you cannot see and for opening up a floor or wall to get at it. Your own contents policy deals with your belongings.
The written report gives the location, methods, readings and photographs, so both households can see which flat and which pipe the water came from. The report goes to whoever booked, after full payment for the visit has come in, and they can share it with the neighbour, the agent and either insurer. The insurer alone decides whether to pay a claim. Any opening up should start at the mark, and the leak is only certain once that pipe has been uncovered.
Agreeing access with the flat above
The flat above has to let us in, and that can be the awkward part. It helps to explain that the visit is there to find the source from the surface and ends with a report both households can use. We need to reach the bathroom, the kitchen, any airing cupboard, the stop tap and the boiler, and we may need to run their taps, shower and toilet while someone watches below.
If the upstairs flat is rented, the landlord or letting agent arranges access with the tenant. If it is empty, the owner or agent can leave keys. Where a neighbour will not cooperate and the damp keeps spreading, put your requests in writing and involve the managing agent. Many leases let the freeholder enter a flat for repairs after giving notice, but check yours or take advice before relying on that.