In Cambridge, 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.

Signs you need roof lantern leak repairs
- Brown staining or bubbling paint on the plasterboard lining around the lantern
- Damp patches on the ceiling a short distance from the lantern
- A leak that only appears in wind-driven rain from one direction
Why it happens
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.
The kerb or roof junction
If the flat roof membrane isn't dressed high enough up the kerb, or the kerb has no fall, water sits against the joint and finds its way in under the lantern.
About Cambridge and the CB1 area
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.
If you're just outside Cambridge, we also cover Newmarket (13 miles), Ely (15 miles), Huntingdon (16 miles).
Guide prices for roof lantern leak repairs in Cambridge
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?
In England, like-for-like repairs to a roof lantern don't usually involve building control. A full replacement or a bigger opening is controlled under the Building Regulations 2010, so we set out the route in writing first. 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 Cambridge: questions
How do I get a price for roof lantern leak repairs in Cambridge?
Send a few photos of the lantern and the problem, with your Cambridge postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Can you repair a lantern someone else installed in Cambridge?
Yes. We repair lanterns whoever fitted them. If yours is still under the installer's warranty, contact them first so you don't affect it.
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.
Will you show me what was wrong?
Yes. We photograph the failed detail and the finished repair and send them to you with the invoice.
Other lantern repairs in Cambridge
- Roof lantern resealing in Cambridge
- Glazing bar and capping repairs in Cambridge
- Cracked lantern glass replacement in Cambridge
- Roof lantern replacement in Cambridge
- Orangery lantern repairs in Cambridge
- Commercial roof lantern repairs in Cambridge
Roof lantern leak repairs near Cambridge
More about roof lantern leak repairs · All roof lantern repairs in Cambridge