What to do if…
a damp patch or water is spreading along a wall and you cannot find the source

What to do now

1. Move people, pets and movable belongings away from the wet wall. Keep clear of any bulging plaster, sagging ceiling edge or falling material.
2. Check from a safe distance whether water is near a socket, switch, light fitting, appliance or consumer unit. Do not touch anything electrical in or beside the wet area.
3. If the consumer unit is dry and you can reach it without crossing water or touching a wet surface, switch off the electricity supply. Leave it alone if the route or unit may be wet. Call 999 if there is fire, smoke, sparking or another immediate threat to life.
4. If it is safe and you know where it is, close the internal mains stop tap by turning it clockwise gently. Stop if it is stuck or begins to leak.
5. Avoid using taps, showers, toilets, washing machines and dishwashers while the source remains unknown. Ask other occupants to avoid using them too.
6. Check only safe, accessible places for an obvious cause, such as an overflowing sink or bath, a leaking appliance hose, a radiator, a pipe beneath a sink, rain entering around a window or water coming from the property above. Do not dismantle fittings.
7. Contact an emergency plumber. Tell them where the patch is, how quickly it is spreading, whether closing the stop tap changed it and whether electrical fittings are nearby.
8. If you rent, report the problem immediately through your landlord’s, council’s or managing agent’s emergency repair route. Give notice in writing as well when practical.
9. In a flat or shared building, contact the building manager, freeholder or emergency maintenance service. Alert the occupant above or beside you so they can check for an overflow or leak without entering their home yourself.
10. Put a container beneath drips only when the area is electrically safe and nothing overhead is bulging. Use towels to limit spreading water without blocking your route out.
11. Take photographs from a safe position and note the time and edge of the damp patch. Check whether it continues to grow after the mains water is turned off.