Water Is Dripping From A Light Fitting

Key takeaways

• Isolate the circuit at the consumer unit. A wall switch only breaks one wire and the fitting can stay live.
• Do not touch the fitting, the switch or the drip itself while the circuit is on.
• A ceiling that is bulging or sagging can come down as one piece and is a physical hazard as well as an electrical one.
• Water reaching a light fitting has usually travelled some distance, so the roof defect is rarely directly above the light.
• The electrics need checking by an electrician after the water has stopped, even if everything appears to work.

The first two minutes

Go to the consumer unit and switch off the circuit that feeds the affected room, or the main switch if you are not certain which one it is. A light switch on the wall interrupts one conductor only, so the fitting above can remain live even with the switch off. Then keep everyone out of the room, including pets, and put a bucket or a bowl under the drip with an old towel underneath to stop splashing. Do not stand on a chair to catch water at the ceiling, and do not try to remove the light fitting to let the water out. Once the power is off and the room is clear, the emergency part is over and you can think clearly about the rest.

Why a wall switch is not enough

In a standard domestic lighting circuit the switch breaks the live feed to the lamp, but the switch wiring, the ceiling rose and the loop at the rose can still carry voltage from the rest of the circuit. Water sitting in a ceiling rose can therefore bridge conductors that are still energised even though the light is off and the room is dark. That is the specific reason the advice is always to isolate at the consumer unit rather than at the switch. If your consumer unit has residual current protection and it has already tripped, leave it off. A tripped device is doing its job, and resetting it while the fitting is still wet simply re energises the fault.

The sagging ceiling problem

Water is heavy. A soaked area of plasterboard holds a surprising load, and once the board has softened and the fixings have started to pull through, the whole panel can drop at once rather than gradually. Look for a bulge, a visible sag, a crack that has opened up, or plaster that has started to bow away from the ceiling line. If any of those are present, treat the room as out of use entirely. Some people deliberately pierce a bulging ceiling to let the water out in a controlled way. That does work, and it does reduce the risk of a sudden collapse, but it should not be done while the circuit is live or by anyone standing directly under it.

Where the water is actually coming from

A ceiling light is a hole in the ceiling, which makes it the lowest and easiest exit for water that has been travelling across the top of the plasterboard. That does not mean the leak is above the light. Water lands somewhere on the roof structure, runs down rafters, along the top of the ceiling and across the joists, and finds the first opening. It can travel several metres before it reaches a fitting. The two most common sources are a roof defect such as a failed flashing or a slipped tile, and a plumbing leak from a bathroom, tank or heating pipe above. Which of the two it is matters, because one needs a roofer and the other needs a plumber, and the wrong call wastes a callout.

Roof or plumbing? How to tell quickly

The simplest test is weather. If it started during or shortly after heavy rain, and there has been no recent plumbing work, the roof is the likely source. If it started with no rain at all, or if it continues steadily through dry weather, suspect plumbing. Smell is a second clue: water from a roof usually smells of dust and timber, while water from a heating system often has a distinct metallic or inhibitor smell and may be discoloured. Position is a third: a drip directly below a bathroom, an airing cupboard or a loft tank points at plumbing, whereas a drip below a plain roof slope with a chimney or valley nearby points at the roof. If it is plumbing, turning off the water at the stopcock will usually slow the flow within minutes, which is a quick and safe test to run.

What not to do

Do not use the light to check whether it still works. Do not put a bucket on a chair or table under the fitting and then climb up to move it. Do not go into the loft with a torch while water is running through the ceiling below, because you cannot see where the joists are through wet insulation and a foot through the ceiling makes a small problem much larger. Do not go outside and up a ladder in the rain to look at the roof. Every year the Health and Safety Executive records falls from height as one of the biggest causes of serious injury in Britain, and a wet roof in bad weather is exactly the situation those figures come from.

When this is a genuine emergency

Treat it as immediate if water is running rather than dripping, if the ceiling is sagging, if the consumer unit has tripped and will not reset, if there is any burning smell, or if the property has vulnerable occupants who cannot easily be kept out of the room. In those cases the roof needs making safe rather than diagnosing, and a temporary cover to stop water entering is a legitimate first job with the proper repair to follow. It is less urgent, though still not something to leave, if the circuit is safely off, the drip is slow, the ceiling is firm, and the weather has passed. In that situation a planned visit in daylight is usually a better repair than a rushed one in the dark.

Afterwards: the part people skip

Once the water has stopped, two things still need doing. First, the electrics need inspecting before that circuit goes back into use. Water inside a ceiling rose or a downlight can leave corrosion and tracking that does not announce itself, and a fitting that works today can fail later. Second, the ceiling needs to dry properly before any repair, which takes weeks rather than days, and the loft insulation above it almost certainly needs replacing rather than drying. Wet mineral wool loses most of its insulating value and stays damp long after the leak is fixed, which then causes condensation problems of its own. It is also worth photographing everything before anything is cleaned up or repaired, including the fitting, the ceiling and the wet insulation above it, because that record is what an insurer will ask for and it cannot be recreated afterwards.

Frequently Asked Questions

Can I just turn the light off at the wall and leave it?

No. A wall switch breaks only one conductor, so the ceiling rose can remain live and water inside it can bridge connections that are still energised. Isolate the whole lighting circuit at the consumer unit, or the main switch if you are unsure which circuit it is, and leave it off until an electrician has checked the fitting.

My RCD keeps tripping. Should I keep resetting it?

No. A device that trips repeatedly is detecting a genuine fault, most likely water bridging conductors. Resetting it puts voltage back into a wet fitting. Leave the affected circuit off, use other rooms, and have it looked at. If the whole house keeps tripping, leave the main switch off and treat it as urgent.

Is the leak directly above the light?

Usually not. A light fitting is the easiest exit for water that has already travelled across the top of the ceiling, sometimes several metres from where it entered the roof. This is why a proper inspection starts in the loft, tracing run marks back uphill, rather than by repairing the roof directly above the drip.

Should I make a hole in a bulging ceiling to drain it?

It can be the right call, because a controlled release is safer than an uncontrolled collapse, but only with the circuit isolated and nobody standing underneath. If the bulge is large, if you are unsure, or if the circuit cannot be turned off, keep the room closed and get someone out instead.

Will my insurance cover water damage from a roof leak?

Policies commonly cover sudden damage such as a storm lifting tiles, and commonly exclude gradual deterioration and the cost of repairing the roof itself. Damage to ceilings, decoration and contents is often treated differently to the roof repair. Contact your insurer before authorising work, and photograph everything before it is cleaned up.

How soon can I use the light again?

Not until the water has stopped, the fitting has been inspected, and the ceiling has dried. Water leaves corrosion and carbon tracking inside fittings that can cause a fault weeks later, so the sensible order is stop the leak, dry the structure, have the circuit and fitting checked, then put it back into use.