In Westminster, as everywhere, a roof lantern leak is almost always a failed seal, a lifted capping, blocked eaves drainage or a problem where the kerb meets the flat roof — not a failed lantern. Send photos and we'll tell you what we think has failed.

What you might be seeing
- Water running down the inside face of the glass
- Damp patches on the ceiling a short distance from the lantern
- A leak that only appears in wind-driven rain from one direction
What usually causes it?
Failed silicone or glazing tape
UV and thermal movement break down the seal between capping, gasket and glass. Once a gap opens, water tracks along the bar and drops at the lowest point.
Lifted or misaligned cappings
Top cappings clip or screw over each glazing bar. If one has lifted, been knocked or was never seated, rain gets straight under it.
Covering Westminster and nearby
Drier, sunnier parts of the UK are kinder to seals than the wet west, but strong sun ages sealant, gaskets and plastic end caps, and south- or west-facing lanterns can make rooms very warm. Solar control glass and an opening vent help.
London's extensions are often tight to neighbouring walls and roofs. Where a repair needs access over a neighbour's property, we'll tell you in advance so you can arrange it.
We also cover nearby Pimlico (1 mile), Chelsea (2 miles), Battersea (2 miles).
How much should it cost?
Guide price for roof lantern leak repairs: £195–£595 ex VAT (£234–£714 inc VAT), per lantern. Towers or scaffold, where needed, are priced into the quote. Your fixed price is confirmed in writing before any work starts.
Do you need permission in England?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in England. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010; we confirm in writing which route applies before any replacement. Listed buildings need listed building consent from the local council for alterations, and conservation areas can have extra controls; like-for-like repairs are treated differently from changes, so check with the council's conservation officer first.
How does it work?
- Send photosWhatsApp or upload a few photos and tell us when it leaks.
- Guide priceWe reply with a guide price and whether a visit is needed.
- Fixed price in writingYou approve the price and the date before anything starts.
- Repair and testWe fix what's failed, water-test where it matters, and send photos.
Roof lantern leak repairs in Westminster: questions
How do I get a price for roof lantern leak repairs in Westminster?
Send a few photos of the lantern and the problem, with your Westminster postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Which places near Westminster do you cover?
As well as Westminster, we cover nearby Pimlico, Chelsea, Battersea, Brixton and the rest of Greater London.
How much does a roof lantern leak repair cost?
Most leak repairs fall between £195 and £595 ex VAT for a standard lantern with ladder access. The fixed price is confirmed in writing before any work starts.
Can you fix the leak in the rain?
We can make the lantern safe in wet weather, but sealants and tapes need a dry, clean surface to bond, so permanent repairs are done in a dry window.
Other lantern repairs in Westminster
- Eaves beam and gutter repairs in Westminster
- Misted glass unit replacement in Westminster
- Solar control and self-cleaning glass upgrades in Westminster
- Opening vent and actuator repairs in Westminster
- Urgent leak make-safe in Westminster
- Roof lantern replacement in Westminster
Roof lantern leak repairs near Westminster
More about roof lantern leak repairs · All roof lantern repairs in Westminster