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. We carry out roof lantern resealing across South Glamorgan, with a guide price from your photos and a fixed price in writing before any work starts.
Signs you need roof lantern resealing
- 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
What usually causes it?
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 South Glamorgan
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.
What should you expect to pay for roof lantern resealing in South Glamorgan?
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 South Glamorgan: questions
How much does it cost to reseal a roof lantern?
A standard-size lantern on a single-storey extension is usually £245–£495 ex VAT. Larger lanterns, difficult access or gasket replacement add to that, and you get the fixed price in writing first.
How long does resealing take?
Most domestic lanterns take a few hours in dry weather.
Which towns in South Glamorgan do you cover?
All of South Glamorgan, including Cardiff, Barry, Penarth, Cowbridge, Llantwit Major. Rural and remote addresses are covered by arrangement.
How do I get a price for roof lantern resealing in South Glamorgan?
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 South Glamorgan
- Glazing bar and capping repairs in South Glamorgan
- Ridge and hip repairs in South Glamorgan
- Cracked lantern glass replacement in South Glamorgan
- Slipped glass panel repairs in South Glamorgan
- Aluminium roof lantern repairs in South Glamorgan
- Orangery lantern repairs in South Glamorgan
Nearby areas
- Roof lantern resealing in Mid Glamorgan
- Roof lantern resealing in Gwent
- Roof lantern resealing in West Glamorgan
- Roof lantern resealing in Powys
- Roof lantern resealing in Dyfed
More about roof lantern resealing · All roof lantern repairs in South Glamorgan