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 Llanelli (SA15) 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.
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 Llanelli and the SA15 area
Wind-driven rain is the real test of a roof lantern, and the wetter west sees plenty of it. Leaks that appear only in a storm from one direction usually point to the cappings or eaves on that face — a useful clue when you send us photos.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
We cover Llanelli as part of Dyfed, about 13 miles from Carmarthen.
If you're just outside Llanelli, we also cover Gorseinon (5 miles), Swansea (10 miles), Ammanford (11 miles).
Guide prices for roof lantern leak repairs in Llanelli
Typical range: £195–£595 ex VAT, which is £234–£714 with 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 Llanelli: questions
Do you cover Llanelli?
Yes. We cover Llanelli, including the SA15 postcode area, as part of Dyfed. 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.
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 Llanelli
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- Cracked lantern glass replacement in Llanelli
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- Roof lantern respraying in Llanelli
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Roof lantern leak repairs near Llanelli
More about roof lantern leak repairs · All roof lantern repairs in Llanelli