Most leaks around a roof window are not the glass. Flashing, sealing, condensation and the roof around the frame account for nearly all of them.
Roof windows are common in Hengrove's bungalows and loft conversions, and when one drips the first thought is the window itself. In practice the glass is rarely at fault. The leak usually comes from the way the window meets the roof, or from damp air inside the room, so we look at both sides.
The flashing around the frame
A roof window is matched to a flashing kit for the type of roof covering. If the kit is the wrong one, was fitted badly or has been disturbed, water gets in at the corners or along the sides. Tiles that have slipped next to the frame can have the same effect.
Sealing and seals that have aged
Seals and sealant around a window harden and crack over time. Water finds a gap, runs behind the frame and appears on the lining or ceiling. Fresh sealing can help in some cases, but it will not cure a flashing that was never right, and we check which you have.
- Cracked or shrunk sealant at the frame edges
- Gaps between the flashing and the tiles
- Staining that starts at the corners of the lining
Condensation that looks like a leak
Warm moist air inside the room condenses on cold surfaces, and the water runs down the glass and frame. It often shows on cold mornings with no rain at all. Poor lining, little insulation or missing vapour control around the opening can make it worse. The fix is inside the room, not on the roof.
Misting between the panes is different. It means the sealed unit has failed, and the usual remedy is a replacement unit or window rather than any repair to the flashing or the roof around it. We can tell the two apart by looking.
The roof around the window
Sometimes the real fault is a damaged covering above the window, a blocked valley or a failed ridge higher up. Water runs down and shows at the window, so the window gets the blame. We trace the source before deciding what to repair, and look in the loft for stains and damp timbers.
What we do about it
We inspect inside and out, from the ground and the loft, then decide whether the answer is a new flashing, repair to the roof covering, better lining and insulation, or a replacement window. We explain which, and why, before any work starts, and photographs are shared so you can see the cause.
Make a note of when it drips, whether it follows rain or cold mornings, and photograph any staining. That history often points straight at the cause. Please stay on the ground and inside the house while you collect that information, and leave the checking of the roof itself to us.
Frequently Asked Questions
Does a leaking window mean it needs replacing?
Not always. Many leaks are put right by correcting the flashing or the covering around the frame. We replace the window when it is worn out, the sealed unit has failed or the frame is damaged. We tell you the cause plainly.
Why does mine only drip in cold weather?
That points towards condensation instead of rain getting in. Warm air meets a cold surface, so check whether the lining, insulation and vapour control around the opening are doing their job. We can tell the difference on site.
Can I seal it myself?
We would advise against it. Extra sealant can trap water, hide the real fault and make the repair harder. Stay on the ground and inside the house, take photographs, and call us for a proper look.
Talk to our team about VELUX and roof window installation in Hengrove
Every roof is different — the fastest way to get an accurate answer is a quick chat with our team.