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 from Falmouth (TR11) and we'll tell you which it is — with the price agreed in writing before any work.

Is it time for roof lantern leak repairs?
- Drips from a glazing bar or the eaves beam when it rains
- Brown staining or bubbling paint on the plasterboard lining around the lantern
- Damp patches on the ceiling a short distance from the lantern
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.
Blocked eaves drainage
Most lanterns collect water in a channel inside the eaves beam and let it out through weep slots. Leaves, moss and grit block the slots and the channel overflows indoors.
Roof lanterns in Falmouth
Western and upland parts of the UK get more rain and more wind-driven rain than the east, and that's what finds weak cappings and blocked eaves first. Lanterns here benefit from a check of the bars on the most exposed face and a clear eaves channel before winter.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
From Truro to Falmouth is roughly 8 miles — all part of the Cornwall area we cover.
We also cover nearby Truro (8 miles), Redruth (9 miles), Camborne (11 miles).
How much should it cost?
Most roof lantern leak repairs jobs come in between £195 and £595 ex VAT (£234–£714 including 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 Falmouth: questions
Do you cover Falmouth?
Yes. We cover Falmouth, including the TR11 postcode area, as part of Cornwall. Send photos by WhatsApp or the form for a free guide price, and we'll confirm the fixed price in writing before any work starts.
Can you repair a lantern someone else installed in Falmouth?
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.
Do I need to be home?
If we need to water-test or check the inside of the lantern, yes. Exterior-only work can sometimes be done with access arranged in advance.
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 Falmouth
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- Misted glass unit replacement in Falmouth
- Condensation diagnosis and fixes in Falmouth
- Urgent leak make-safe in Falmouth
- Roof lantern replacement in Falmouth
- Commercial roof lantern repairs in Falmouth
Roof lantern leak repairs near Falmouth
More about roof lantern leak repairs · All roof lantern repairs in Falmouth