Leak from the flat above and nobody is in

It is one of the worst calls to make. Water is coming through your ceiling, you go upstairs, and nobody answers. The flat might be empty between tenants, a short let with guests out for the day, or a second home whose owner is abroad. Meanwhile the stain is spreading.

This guide is for that situation. It assumes you have done the first safety steps and now need to get the water stopped at its source.

First, make your own flat safe

• Switch off electrics near the water at the consumer unit, if you can do so without touching anything wet. If water is coming through a light fitting, do not use the switch.
• If the ceiling is bulging, keep out from under it.
• Put buckets and towels down and move belongings.
• Take photos and a short video, with the time.

If you smell gas at any point, go outside and call 0800 111 999.

Why this happens so often in Kensington and Chelsea

Kensington and Chelsea has a lot of flats that are empty for long periods. Stucco houses in Earl’s Court, South Kensington and Notting Hill are split into many flats, and some are short lets or homes used only part of the year. In the 2021 Census, 23.5% of households in the borough lived in converted houses and 56.7% in purpose built flats.

A slow leak in an empty flat can run for days before anyone notices. By the time it reaches the flat below, the floor void above may be saturated.

Who can get into the flat

Person	How they help
Managing agent or freeholder	Usually has a right under the lease to get access to investigate a problem
Porter or concierge	Often holds keys or knows who does
Letting agent	Holds keys for rented flats and can contact the owner
Short let host	Can be reached through the booking platform or a key holder
Owner	Details are usually held by the managing agent
Fire brigade	For real emergencies with danger to life or property

The Leasehold Advisory Service says that if your neighbour is not cooperating, the landlord or managing agent will usually have a power under the lease to get access to a flat to investigate, although the lease may say you need to cover their costs. They should also have contact details for the owner, and for the tenant if the flat is rented.

Shutting the water off from outside the flat

You may be able to stop the leak without getting in, if the problem is on the water supply rather than a waste pipe.

A communal stop valve. Thames Water notes that flats may have a communal stop valve where the supply enters the building. In a converted house this might be in the hall, under the stairs or in the cellar. In a mansion block it might be in a plant room or a riser cupboard the porter can open.

The outside stop valve. For a converted house on one supply, the outside stop valve under the cover in the pavement will cut off the whole building. Thames Water says it should only be used in an emergency, may need a stopcock key, and if the supply is shared it will cut off the neighbours too. Tell them first.

Turning off the supply will not stop a leak from a waste pipe, such as a bath or shower waste that only leaks when used. In an empty flat, waste leaks usually stop on their own once nobody is using the bathroom. A leak that keeps going is far more likely to be on a supply pipe, a tank or a toilet cistern that keeps filling.

When to call the fire brigade

The Leasehold Advisory Service says that in an emergency you can contact the fire brigade. London Fire Brigade attends floods of all kinds and attended 6,526 flood related incidents in 2017. It also says that for a leaking tap it is probably best to call a plumber.

Call 999 if a ceiling looks like it may collapse, water is pouring into electrics and you cannot switch off, or anyone is at risk. Otherwise, keep working through the managing agent and the communal valve.

Once someone gets in

When the managing agent or key holder arrives, ask for a plumber to go in at the same time. The plumber can isolate the flat, find the source and make it safe. Common causes in an empty flat are:

• a cistern fill valve stuck open, overflowing into the pan or onto the floor
• a pipe that froze in an unheated flat and split on the thaw
• a washing machine or dishwasher hose that failed
• a dripping joint under a bath that has been leaking slowly for weeks

Ask the plumber for a written note of the cause and photos. You will need them for the insurance and for any discussion about who pays. Our guide on who is responsible for a leak from the flat above explains the usual position.

Keep a record

Write down who you called and when, what they said and when access was given. If the leak caused serious damage because nobody responded, that timeline will matter later.

If you own a flat that is often empty

Turn off your stop tap when you leave for more than a night or two, unless the heating needs it. Make sure the managing agent has a key or a contact who can be reached. Leave the heating on low in cold weather. The Leasehold Advisory Service gives the same advice to prevent frozen pipes. Check whether your insurance limits cover when the flat is unoccupied.

If you need someone to trace and stop the leak once access is arranged, see our page on water leaking through the ceiling.