The short answer
Turn off the power to that circuit at the consumer unit, keep people away from the fitting and do not touch the switch or the light while it is wet. Then catch the water with containers, move belongings and take photographs. Once the area is safe, find where the water is entering the roof and arrange a qualified electrician to check the wiring before the light is used again.
The first minutes: make it safe
Water and mains electricity do not mix, and a ceiling light is directly in the path of any leak. The priority is to stop anyone being hurt, so everything else waits until the power is off.
- Do not touch the light, its switch or any wet surface near it.
- Go to the consumer unit, the fuse box, and switch off the circuit that feeds the light. If you cannot tell which one it is, or you cannot reach the box without crossing wet floor, switch off the whole house at the main switch.
- Keep children and pets out of the room.
- If you see sparking, smell burning or the ceiling is sagging under the weight of water, leave the room and call 999.
Leave the light switched off at the fuse box until an electrician has checked it. A fitting that works after drying out may still have damaged wiring behind it.
Containing the water
Once the power is off, the next job is to reduce the damage. Put a bucket or basin under the drip, with a towel in the bottom to cut the splashing, and move furniture, rugs and anything valuable out of the way. Lift electrical items, such as lamps and chargers, off the floor and away from the area.
A ceiling that is bulging is holding water above it. That weight can bring the plasterboard down, so keep clear of the bulge. If you need to release the water, do it from a safe position, with the circuit off, by piercing the lowest point of the bulge with a long implement so it drains into a container. If you are not comfortable doing that, leave it and call for help.
Take photographs of the stain, the fitting and any damage as it happens, and note the date. They help with any later insurance claim, and finding a roof leak explains why the stain is often far from the real entry point.
Why it comes through the light
A light fitting is a hole in the ceiling, and a recessed downlight is a bigger one. Water that has collected above, on top of the plasterboard or in the insulation, looks for the easiest way down and often finds the cable entry. The light is where the water becomes visible, not necessarily where it started.
That water has usually travelled. It can come from a failed seal at a soil pipe, a lifted tile, split lead around a chimney or parapet, a blocked gutter or an overflowing tank. In a top-floor flat or a loft conversion there is less void between roof and ceiling, so water reaches the fitting sooner. Our answer on a soil pipe roof leak describes one common source.
Not every wet ceiling light is a roof leak. A leaking bathroom above or a burst pipe does the same, and condensation can form on a cold fitting. If it is raining and the leak began with the weather, the roof is the first suspect, and our page on leak or condensation shows how to separate them.
Who to call, and in what order
Two trades are needed, and the order matters. First, a qualified electrician checks the circuit and the fitting once the water has stopped, because wet insulation and damp cable joints are a hazard even after the ceiling looks dry. Second, a roofer finds and repairs the source so it does not happen again.
If rain is still coming in, a roofer may need to make the roof safe first, covering the entry point so the ceiling can dry out. Leaks rank high on our list, and a roof make-safe describes what that first visit involves. The survey traces the water to where it gets in, with pictures taken on your roof.
If the water may be coming from next door, your options differ, and a neighbour's roof in poor condition covers a related situation. For tenants and leaseholders, the landlord or the building's managing agent is normally the first call.
Drying out and the repair
Once the source is fixed, the ceiling needs time to dry. Wet plasterboard and insulation can stay damp for a long while without being obvious, and trapped moisture leads to mould and a stain that keeps returning. Opening windows, running a dehumidifier and lifting the insulation back from the area all help. Plasterboard that has been badly soaked may need cutting out and renewing.
Insulation deserves a look too. Mineral wool that has been soaked can slump and lose its value, and wet material sitting on the board keeps it damp. Lift out and replace anything that stays wet, and ask the electrician to check any cable runs that crossed the soaked area before the ceiling is closed up again.
Do not repaint a stain until the area is truly dry, or the damp will bleed through again.
For the roof, the repair follows the cause, whether that is renewed lead, a replaced tile, a cleared gutter or a refitted collar. Your fixed price is written down after the survey, and until the ceiling is dry, keep that light switched off at the consumer unit and have an electrician test the circuit before using it. The roof repairs in Bath hub lists the faults we deal with in Bath and the area around it.
