If your Velux window has been bone dry for months and then suddenly starts dripping the morning after a storm, that timing isn’t a coincidence. It’s actually one of the most useful clues you can give an engineer before they’ve even arrived, because a leak that only shows up under heavy, wind-driven rain points to a fairly specific set of causes, and most of them are quicker and cheaper to fix than people expect.
Why Storms Expose Leaks That Normal Rain Doesn’t
Ordinary rainfall drops fairly straight down and sheds off a roof the way it’s designed to. Storm conditions are different: wind drives rain sideways and upwards under tiles, forcing water into places gravity alone would never take it. A window that copes fine with a typical wet Tuesday in the North East can still let water through when a proper storm comes off the coast, because the fault it has doesn’t need much pressure or angle to exploit, just more than usual.
This is exactly why September and October tend to be busy months for leak call-outs. Nothing about the window has necessarily got worse overnight. The weather has simply found a weak point that’s been sitting there quietly for a while.
Failed or Worn Flashing Kit
This is the cause behind the majority of storm-triggered leaks we see. The flashing kit is the metal collar that sits between the window frame and the surrounding tiles, and its whole job is to direct water around the window rather than let it track underneath. Flashing has a working life of roughly 10 to 15 years depending on exposure, and once it starts to corrode or lift slightly at a corner, a gap opens up that’s often too small to notice by eye but more than enough for wind-driven rain to exploit.
Roofs facing the prevailing weather, generally west and south-west across most of the UK, tend to see flashing fail earlier than more sheltered elevations. If your Velux window is on that side of the house and it’s been in for over a decade, flashing is the first thing worth suspecting. It’s one of the faults covered in more depth in our full guide to Velux window repairs and maintenance, alongside the other common causes that don’t always show up as clearly as a storm-triggered leak does.
Felt Collar Failure
Sitting just beneath the flashing is a felt or membrane collar that ties the window into the roof’s underlay, providing a second line of defence if any water does get past the flashing itself. Felt degrades with age and UV exposure, and once it splits or perishes, that backup layer is gone. On its own, a failed felt collar with sound flashing above it rarely causes problems. Combined with flashing that’s also started to wear, it’s often the difference between a very minor drip and a proper leak making its way onto your ceiling.
Incorrect Original Installation
Less common, but worth ruling out, particularly if the leak started fairly soon after the window was fitted rather than after ten-plus years of service. A flashing kit that doesn’t match the roof covering it’s fitted to (using a kit designed for plain tiles on an interlocking tile roof, for example) will often look fine for months or even a couple of years before a storm with the right wind direction finds the mismatch. The same applies to a window that’s been fitted slightly out of square, or where the surrounding tiles weren’t properly dressed back into place afterwards.
If your Velux window is under five years old and has started leaking in a storm, this is worth mentioning to whoever comes out, since it changes what they’ll check first.
What to Do This Week
Storm damage rarely announces itself politely, so a few sensible steps in the meantime:
- Note exactly when the leak appears and from which direction the wind was blowing. This single piece of information often narrows down the cause before anyone’s even climbed a ladder.
- Place a container under the drip and protect flooring or furniture nearby. Simple, but it’s the difference between a damp patch and a ceiling repair bill.
- Avoid the temptation to seal anything yourself with sealant from the local hardware shop. It rarely holds, and it can make the actual repair harder by hiding where the water’s really getting in.
- Get it looked at within the week rather than waiting to see if it dries out. A leak that’s found its way in once will find the same route again next time it rains, and continued water ingress around timber frames or plasterboard adds up fast.
If any of this sounds familiar, the quickest way to get it sorted is to get in touch with our team and book a same-week callout. Storm-triggered leaks are exactly the kind of job we try to turn around fast, since leaving them any longer tends to turn a straightforward flashing repair into a bigger one.
Frequently Asked Questions
Why has my Velux window never leaked before and started now?
Most storm-triggered leaks come from flashing or felt that’s been quietly wearing for years without enough wind-driven rain to expose it. The window hasn’t suddenly failed; a stronger storm has simply found a weakness that was already there.
Is a storm-related leak covered under guarantee?
Velux’s own product guarantee runs for 10 years on the window itself, though flashing and installation issues are usually treated as separate from the window unit. Workmanship carried out by our team carries its own 1 year guarantee, so if a leak relates to something we’ve previously installed, it’s worth mentioning that when you call.
Can I fix a Velux leak myself after a storm?
Clearing debris from the drainage gutter along the top of the flashing is safe enough for most homeowners if it can be done without getting onto the roof. Anything involving the flashing or felt collar itself needs a professional, both for safety and because DIY work here often causes more damage than it fixes.
How quickly can someone come out after a storm?
We prioritise storm-related leaks for a same-week callout wherever possible, since water finding its way in once tends to repeat on the next heavy rain if it isn’t dealt with.