Water dripping from a light fitting is not safe to leave. Switch the lighting circuit off at the consumer unit, not at the wall switch, and do not touch it. The water is usually from a bathroom, loft tank, radiator pipe or roof above, and the fitting is simply the lowest hole. An electrician checks the fitting; a leak survey finds the source.
You looked up because you heard a drip and there it is: water forming on the ceiling rose or running down the pendant flex, dripping off the bulb onto the floor. Every instinct says get a bucket and look closer. Do the bucket. Do not do the looking closer, not yet. Water and mains electricity in the same fitting is the one leak situation where the wrong first move can hurt you, so this guide starts with safety, then explains why water so often chooses the light fitting to come through, then walks through what is likely above it. Once the power is off and the area is safe, our water leak detection service traces the water back to its source without opening the ceiling up on a guess.
Safety first, in this order
- Go to the consumer unit. Switch off the circuit labelled for that floor’s lighting. If the labels are unclear or missing, switch off the main switch and put the whole house in the dark for now. A wet circuit can still be live with the wall switch off, and the wall switch itself may be on the same wet cable run.
- Dry hands, dry floor. Do this standing on a dry surface. If the consumer unit itself is wet or water is running near it, do not touch it; leave it and ring an electrician.
- Keep clear of the fitting. Do not try to remove the shade, unscrew the bulb or take the rose off. Do not wipe the water off it. Put a bucket underneath and leave it alone.
- Check the ceiling around it. If the plasterboard is bulging, it is holding water and needs draining carefully at the lowest point away from the fitting. The guide to a ceiling bulging with water covers that step by step.
- Turn off the stopcock under the kitchen sink and, if you have one, the gate valve on the loft tank, while you work out where the water is from.
If the water is running rather than dripping, or the ceiling is sagging, treat the ceiling as the priority once the power is off. Water gathering above a fitting adds weight to the board around the hole, and that is the section most likely to give way. A bucket under the fitting and a second under the lowest part of the sag covers both.
Do not use the light again, even after it looks dry, until an electrician has inspected the fitting and the wiring above it. A fitting that has had water inside it usually needs replacing, and the connections in the ceiling void may have corroded.
Why the water comes out at the light and not somewhere else
A ceiling is a sealed sheet of plasterboard or lath and plaster with very few holes in it. The light fitting is one. Water that escapes above the ceiling spreads across the top of the board, runs along the joists to the lowest point, and drops through the first opening it reaches. The fitting’s hole, and the cable passing through it, act as a drain. That is why the water is at the light and it is also why the leak is frequently not directly above it. The escape point can be a couple of metres away, sometimes in a different room, with the water travelling along a joist or a pipe to reach the hole.
Older Cornish houses make this worse. Joists in a granite or cob cottage are rarely level, so water runs downhill inside the floor void to whichever end has settled lower, and that end may be the far side of the room from the bathroom.
What is above it? The usual sources
| What sits above the fitting | Likely source | Tell-tale sign |
|---|---|---|
| Bathroom or en suite | Failed sealant round the bath or shower tray, a shower waste trap, a leaking toilet pan connector or a supply pipe to the basin | Drips only after someone has used the shower or bath, and stop between uses |
| Loft space | Cold water tank overflowing or split, a pipe joint above the tank, or the roof (slipped slate, lead flashing, blocked valley) | Worse in heavy rain (roof) or constant regardless of weather (tank or pipe) |
| Bedroom or landing | Radiator valve or tail, or the heating pipe running under that floor | Boiler pressure falling, water in the bucket slightly discoloured |
| Kitchen (in a flat or an extension with a room above) | Dishwasher or washing machine hoses, the sink waste, an appliance valve | Drips coincide with appliance cycles |
| A flat above | Their bathroom, kitchen or heating | You have no plumbing above at all |
Look upstairs with a torch, and if you have a loft, look in it. Water on the underside of the roofing felt, a full-to-the-brim tank, or a wet floorboard next to a radiator often gives the answer in five minutes. If the loft is bone dry and there is no bathroom above, the water has travelled, and the guide to a ceiling stain with a dry loft explains where to look next.
Roof or pipe? Wait for the weather
One simple check separates the two biggest groups of cause. If the dripping started during or shortly after heavy rain and eases as the weather dries, the roof is the suspect: a slipped slate, a cracked ridge, a blocked valley gutter, failed flashing round a chimney. Coastal weather in Cornwall drives rain sideways into places that stay dry in an ordinary shower, so a roof that has been fine for years can start letting water in during one south-westerly gale. If the dripping is steady in dry weather, or tied to using a bathroom, the plumbing is the suspect. A roof leak needs a roofer; a plumbing leak needs the pipe found.
Electrician first, then leak detection, or the other way round?
People often ask which trade to ring first. The honest answer is both, but they do different jobs and the order matters less than making sure neither is skipped.
- The electrician makes the circuit safe, inspects the fitting and the connections in the void, replaces what has been wet, and tells you when the lights can go back on. They do not find the leak.
- Leak detection finds where the water is escaping so it can be repaired at the right spot, and provides the report an insurer wants before paying for the ceiling, the fitting and the decoration. It does not certify the electrics.
- The plumber or roofer does the repair once the point of failure is known.
If the ceiling is drained and the source is not obvious from upstairs, get the leak found before the electrician replaces the fitting. There is no point fitting a new light under a ceiling that is about to get wet again.
How the source is found without wrecking the ceiling
A survey for a wet light fitting works from the fitting outwards. Moisture readings across the ceiling and the floor above map how far the water has spread and which direction it came from. Thermal imaging picks out a warm heating pipe or a cold supply pipe sitting against wet material, and shows the shape of the wet patch inside the void rather than the small circle you can see. Where a pressurised pipe is suspected, a pressure or tracer gas test confirms which pipe has failed. The result is a location marked on the ceiling or floor above, and a small opening in the right place rather than a large one in the wrong one. That is what trace and access cover in most buildings policies is meant to pay for, alongside making good afterwards.
We handle leak detection across Cornwall, and a dripping light in a terrace in Penzance or a holiday let in Rock gets the same approach: make it safe, map the water, find the pipe, write it up.
Landlords and holiday lets
If the property is let, a wet light fitting is a landlord’s problem at once. Section 11 of the Landlord and Tenant Act 1985 puts the installations for water, electricity and heating in repair on the landlord, and a tenant should be told to switch the circuit off and keep clear rather than investigate. For a holiday let, the guest needs the same instruction and a clear number to ring, and the changeover team needs to know not to restore the power. A report from the survey helps both the insurance claim and any question later about how the fault was handled.
Frequently asked questions
Can water in a light fitting cause a fire?
It can. Water inside a fitting can bridge live connections, cause tracking across the fitting and overheat cables. It is also an electric shock risk to anyone who touches it. That is why the circuit goes off at the consumer unit before anything else, and why the fitting is checked by an electrician before it is used again.
Is turning off the light switch enough?
No. The wall switch only breaks one conductor and the cable at the fitting can still be live, particularly if the switch is wired on a loop through the ceiling rose. Switch the circuit off at the consumer unit, or the main switch if you are unsure which circuit it is.
The dripping has stopped. Can I turn the lights back on?
Not until an electrician has looked at it. Water leaves corrosion and residue in a fitting and in the connections above, and a fitting that looks dry outside can still be wet inside. Have it inspected and, if needed, replaced, and have the cause of the water found so it does not happen again.
Why is the leak not directly above the light?
Water spreads across the top of the ceiling and runs along joists to the lowest point before it finds a hole to drop through. The light fitting is often the only hole. In older houses with uneven joists the water can travel a couple of metres, so the source is frequently in a different spot from the drip.
Will insurance cover a new light fitting and the ceiling?
Most buildings policies cover damage from escaping water, which normally includes the ceiling, decoration and a damaged fitting. Where the policy includes trace and access, locating the leak and making good the access is covered too. Repairing the pipe that failed is usually excluded. Check your own wording.
Power off, leak still unknown?
Once the circuit is safe, we trace the water back from the fitting to the pipe or fixture that failed, without taking the ceiling down, and give you a report your insurer will accept for the trace and access claim.
