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. We carry out roof lantern leak repairs across Cornwall, with a guide price from your photos and a fixed price in writing before any work starts.

Signs you need roof lantern leak repairs
- 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?
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.
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.
Roof lanterns in Cornwall
Damp, mild winters keep moss and algae growing on flat roofs and lantern frames, which holds water against seals and blocks weep slots. Regular clearing makes a real difference in wetter areas.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
What should you expect to pay for roof lantern leak repairs in Cornwall?
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 Cornwall: questions
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.
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.
Which towns in Cornwall do you cover?
All of Cornwall, including Truro, Redruth, Falmouth, St Austell, Camborne, Newquay. Rural and remote addresses are covered by arrangement.
How do I get a price for roof lantern leak repairs in Cornwall?
Send a few photos of the lantern and the problem with your postcode, by WhatsApp or the form. We reply with a guide price and confirm the fixed price in writing before any work starts.
Other repairs in Cornwall
- Glazing bar and capping repairs in Cornwall
- Eaves beam and gutter repairs in Cornwall
- Aluminium roof lantern repairs in Cornwall
- Opening vent and actuator repairs in Cornwall
- Orangery lantern repairs in Cornwall
- Commercial roof lantern repairs in Cornwall
Nearby areas
- Roof lantern leak repairs in Devon
- Roof lantern leak repairs in Somerset
- Roof lantern leak repairs in Bristol
- Roof lantern leak repairs in Dorset
- Roof lantern leak repairs in Wiltshire
More about roof lantern leak repairs · All roof lantern repairs in Cornwall