We carry out roof lantern resealing in Carmarthen and across the SA31 area. Resealing is the planned, whole-lantern version of a leak repair: we cut out the old, failed sealant, clean every joint back to a sound surface and reseal the cappings, ridge and eaves with materials that suit the frame.

What you might be seeing
- Several small leaks rather than one obvious one
- Sealant applied over sealant from previous patch repairs
- A lantern that is 8–15 years old and has never been maintained
Common causes we find
Sealant past its life
Exposed sealant on a roof takes UV, frost and constant expansion and contraction. It hardens, loses grip and pulls away from the glass.
Patch over patch
Fresh sealant run over old, dirty sealant rarely bonds. It looks fixed for a season and then lets go.
Roof lanterns in Carmarthen
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.
Near the coast, salt in the air is hard on aluminium finishes and fixings; washing the frame occasionally and touching in chips keeps corrosion away.
We also cover nearby Llanelli (13 miles), Ammanford (14 miles), Gorseinon (17 miles).
Guide prices for roof lantern resealing in Carmarthen
Typical range: £245–£495 ex VAT, which is £294–£594 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?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Wales. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010 (as applied in Wales); we confirm in writing which route applies before any replacement. 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 resealing in Carmarthen: questions
Do you cover Carmarthen?
Yes. We cover Carmarthen, including the SA31 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.
Can you repair a lantern someone else installed in Carmarthen?
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 match the colour of my frame?
We use sealants in common frame colours such as anthracite grey, black and white, and match as closely as the range allows.
How long does resealing take?
Most domestic lanterns take a few hours in dry weather.
Other lantern repairs in Carmarthen
- Ridge and hip repairs in Carmarthen
- Upstand and kerb repairs in Carmarthen
- Roof lantern respraying in Carmarthen
- Flat rooflight and skylight repairs in Carmarthen
- Leak investigation and inspection in Carmarthen
- Cleaning and maintenance in Carmarthen
Roof lantern resealing near Carmarthen
More about roof lantern resealing · All roof lantern repairs in Carmarthen