Water leak from the flat above? How letting agents find the source

1. Deal with anything urgent first

If water is coming through quickly, is near a light fitting or socket, or a ceiling is bulging, use the building's emergency arrangements first: isolate what you can and keep people out of the room. A leak survey enquiry is not an emergency call-out booking.

2. Record what the tenant has seen

Ask the tenant where the water appears, when they first noticed it, and whether it is constant or comes and goes. Write down observations separately from guesses. "Water on the bathroom ceiling after the shower upstairs is used" gives the engineer far more to work with than "the upstairs bath is leaking".

• Note the affected room and where it sits in relation to the flats above and alongside.
• Keep dated photographs of the stain as it changes, where it is safe to take them.
• Record any link with water use, the heating or rainfall, without treating it as proof.
• Gather previous plumbing reports, repairs and any pipe drawings you hold.

3. Work out what kind of leak it might be

The pattern is the most useful clue you can pass on. It narrows the search; it does not settle it.

4. Arrange access to the flat above and shared areas

ADI's booking terms say the engineer may need access to the flat above, below or next door, and will usually need access to every property on a shared water supply. They also flag supply pipes that cross someone else's property and houses in multiple occupation where rooms are locked. Lift access is needed for any flat more than two storeys up, because the equipment is heavy. Where a booking involves a landlord, tenants and managing agents, the terms make the person booking responsible for telling everyone involved, including whoever pays, what the appointment needs. Before the appointment, agree:

• which homes and communal areas can be entered at the agreed time;
• who holds each key, and who will meet the engineer;
• who is talking to the block's managing agent and the other occupiers;
• who can approve further investigation if another area needs to be opened.

Confirm access through the occupiers and property representatives concerned. This guide does not give anyone permission to enter another home. The list of what the engineer needs also covers parking, meters and stopcocks.

5. Tell the office about the building's history

Conversions, new bathrooms and boiler replacements all leave pipework behind. In a two-bedroom first-floor flat, a meter showed a small leak with no water in use. Pressure testing, acoustic listening and tracer gas traced it to old hot pipework left buried and still live under the bathroom floor after a switch to a combination boiler, and following it meant investigating the area below the flat. ADI capped off the old pipe and reconnected the tap feed to the newer pipework. Read that case.

That is ADI's residential example; it was not commissioned by a letting agent, and its outcome says nothing about the cause at another property.

6. Keep the leak source apart from the question of who pays

Ask the engineer which system was tested, what evidence was found and what remains uncertain. Share those findings with the landlord, the block's managing agent and the repair contractor, so everyone works from the same account. A technical finding does not by itself decide responsibility or what an insurer covers. The findings and repair guide helps organise that next conversation.

What not to do

• Do not tell the tenant or the neighbour which flat is to blame on the strength of where the stain is.
• Do not open ceilings to chase the stain. Water runs along joists and pipes before it drops.
• Do not assume the case is closed because the stain has dried.