Pitched Roof Skylight Installation

Water Pouring Through a Loft Rooflight: What to Do


If water is coming through a loft rooflight, first move anything valuable clear and put a bucket or container under the drip, then keep away from any loft lighting or electrics near the water and switch that circuit off at the consumer unit if you safely can. Photograph where the water enters and when, note whether it follows rain or the cold, and book a survey. Do not go up onto the roof and do not go poking at the unit from outside. A rooflight sits two storeys up on a slope, wet roofs are lethal, and the cause is found safely from a scaffold and inside the loft, not by climbing up to look.

This answer is the urgent steps. If the water arrived in a storm, see storm damaged rooflight, and if the wet is really condensation from a cold reveal rather than a leak, see draughty, cold loft rooflights.

A container catching water dripping from a loft rooflight reveal onto a protected floor, loft interior in flat grey daylight
Contain it and keep clear of the electrics first. The cause is diagnosed later, safely, not by going up now.

What to do right now

  1. Protect the room. Move furniture, bedding and anything that matters out from under the leak. Lay down a container to catch the drip and towels to stop splash spreading.
  2. Deal with the electrics. Loft rooms and loft spaces often have lighting, sockets and sometimes an electric rooflight actuator near the opening. Water and electricity together are dangerous. Keep away from any fitting the water is near, and if you can do it safely and know which one it is, switch off that circuit at the consumer unit. If in any doubt, switch off and call an electrician, not us.
  3. Catch water above a ceiling if it is spreading. If water is tracking along and pooling above a plasterboard ceiling below the loft, a bulging patch is a warning. A small pierce with a screwdriver into a bulge, over a bucket, releases the water in one controlled place rather than letting the whole ceiling come down. Only do this from a safe standing position.
  4. Do not go onto the roof. This is the important one. Do not put a ladder up, do not climb out onto the slope, do not send anyone up to have a look or throw a tarpaulin over it. We do not advise it and we will not either. The diagnosis is done safely at survey.

We never advise anyone onto their roof, and we do not do emergency roof repairs. A leaking rooflight is genuinely urgent, and we treat it that way with a prompt survey and a same-week replacement assessment where we can. But the answer is never a homeowner or a handyman up a wet slope. It is a safe survey from a scaffold and inside the loft, then a proper replacement. We do not reseal or patch, because on a unit that has failed, patching buys a season and the leak comes back.

Record the evidence

Good evidence makes the survey faster and helps any insurance claim. From inside, safely, note and photograph:

  • Where the water enters: from one corner, one edge, or evenly all round the reveal.
  • When it happens: during or after rain, in wind from a particular direction, or in cold still weather with no rain.
  • What it looks like: clear water, or brown-stained water carrying dirt from the roof build-up.
  • Any staining history: old tide marks on the reveal or the ceiling below suggest it has been happening a while.

Leak or condensation? The tell

Not all water at a rooflight is a leak. A genuine leak follows rain, comes from one edge or corner, and often carries brown staining from the roof. Condensation from a missing insulation collar appears in cold weather whether or not it has rained, forms evenly around all four reveals, and is clear. If your water is even, clear and cold-weather, the fix is the insulation and vapour detailing rather than the flashing, covered on draughty, cold loft rooflights. Either way, the survey settles it.

Reading a wet loft rooflight
What you see Likely cause
Water after rain, from one corner, brown-stained Flashing or covering leak
Water in wind from one direction Driven rain past a short soaker or bridged head flashing
Water even all round, clear, in cold still weather Condensation, uninsulated reveal, not a leak
Sudden heavy flow after a storm Storm damage, see the storm page

How the survey finds the cause

When we come out, the diagnosis is done from inside the loft and from a scaffold or tower, never by walking the roof. We look at where the water tracks to inside, then at the flashing detail from a safe platform outside. The usual culprits, in order:

  • The head flashing bridging the covering above instead of dressing into it, so water runs under. The most common cause, and a setting-out error.
  • A missing or slashed underfelt collar, so anything past the tiles reaches the timber instead of being carried back out.
  • The wrong flashing kit for the covering, leaving gaps that mortar was used to fill, and the mortar has cracked.
  • Short or omitted side soakers, which let go after a couple of years.
  • A perished frame or seal on an older unit, where the window itself has reached the end.

Which of these it is decides the replacement scope. The flashing detail behind most of these is on choosing and fitting the flashing kit, and the leak diagnosis method is on flashing leak diagnosis.

An installer inspecting a rooflight flashing from a scaffold platform in flat overcast conditions, roof access equipment in place
The cause is found from a safe platform and inside the loft. Nobody walks the slope to have a look.

Why replacement, not a reseal

By the time a loft rooflight is leaking enough to pour, the flashing or the unit has failed, and resealing it from outside buys a season at most while disturbing the covering. We replace the unit with a new flashing kit matched to your covering, a fresh underfelt collar and a fresh insulation collar, which resets the whole assembly and is cheaper over any sensible timeframe than repeat visits up a wet roof. The replace-not-patch logic is on rotten rooflights, replace not repair, and if the roof is due for re-covering anyway, doing both together is on whether to replace rooflights when re-roofing.

Common questions about a leaking loft rooflight

What should I do if water is pouring through my loft rooflight?

Move valuables clear and catch the water in a container, then keep away from any loft lighting or electrics near the water and switch that circuit off at the consumer unit if you safely can. Photograph where and when the water enters. Do not go onto the roof or put a ladder up. Book a survey, which finds the cause safely from a scaffold and inside the loft. We treat a leak as urgent and assess a replacement promptly.

Is it a leak or condensation?

A leak follows rain, comes from one edge or corner, and often carries brown staining from the roof. Condensation from a missing insulation collar appears in cold weather whether or not it has rained, forms evenly around all four reveals, and is clear. If yours is even, clear and cold-weather, it is likely condensation and the fix is the insulation detailing, not the flashing. The survey confirms which it is.

Can you just reseal the leak?

We do not reseal or patch as a service. By the time a rooflight is leaking enough to pour, the flashing or the unit has failed, and resealing from outside buys a season while disturbing the covering. We replace the unit with a new flashing kit and fresh collars, which resets the assembly and lasts, and is cheaper over any sensible timeframe than repeat visits up a wet roof.

Get a leaking loft rooflight sorted

Tell us where the water is coming in, when it happens and roughly what the roof is, and we will survey promptly from a safe platform and inside the loft, find the cause, and give you one written fixed price to put it right. We treat leaks as urgent and assess a replacement the same week where we can. Every installation carries a 10-year workmanship guarantee and the installers have 25 years fitting rooflights behind them.

Request a survey and fixed quote for a leaking rooflight in Ipswich, Suffolk or north Essex.

Thinking about this job? We survey across Ipswich, Suffolk and north Essex and give you a fixed price before any work starts, with a 10-year workmanship guarantee.

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Get a fixed quote

Tell us about the roof. We will tell you the price.

A survey costs you nothing and there is no obligation attached to it. We look at the roof build-up, the exposure and the opening, and give you one fixed figure, not an estimate that moves once work starts.

If your rooflight is leaking now, say so and we will prioritise the survey.

  • Fixed price, confirmed in writing
  • 10-year workmanship guarantee
  • Installed to current Building Regulations
  • Your roof is never left open overnight
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