In Cardiff, 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.
Is it time for roof lantern leak repairs?
- Brown staining or bubbling paint on the plasterboard lining around the lantern
- Water running down the inside face of the glass
- A leak that only appears in wind-driven rain from one direction
Why it happens
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.
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 Cardiff
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.
We also cover nearby Penarth (3 miles), Caerphilly (7 miles), Barry (7 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 Wales?
Most lantern repairs in Wales need no approval at all. Where a job turns into a replacement, the Building Regulations 2010 (as applied in Wales) apply and we confirm how the work will be signed off before we start. Listed buildings in Wales need listed building consent from the local planning authority for alterations, with Cadw guidance on historic buildings; check with the council before changing a lantern on a listed property.
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 Cardiff: questions
Do you cover Cardiff?
Yes. We cover Cardiff, including the CF10 postcode area, as part of South Glamorgan. 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.
Do you need to visit to price roof lantern leak repairs?
Not always. Clear photos are often enough for a guide price. Where the cause isn't obvious, a visit to inspect and water-test is charged from £145 ex VAT, confirmed before we come.
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.
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.
Other lantern repairs in Cardiff
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- Cracked lantern glass replacement in Cardiff
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- Roof lantern replacement in Cardiff
Roof lantern leak repairs near Cardiff
More about roof lantern leak repairs · All roof lantern repairs in Cardiff