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. Send photos from Bangor, Gwynedd (LL57) and we'll tell you which it is — with the price agreed in writing before any work.
What you might be seeing
- Cracked, split or shrunken sealant along the bars
- Black mould or dirt lines trapped in old silicone
- Several small leaks rather than one obvious one
Why it happens
Wrong product used
General-purpose or acetoxy silicone can fail early on some frames and coatings. Glazing joints need a low-modulus, compatible sealant.
Patch over patch
Fresh sealant run over old, dirty sealant rarely bonds. It looks fixed for a season and then lets go.
About Bangor, Gwynedd and the LL57 area
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.
Neighbouring places we cover include Llangefni (8 miles), Caernarfon (8 miles), Llandudno (14 miles).
How much should it cost?
Most roof lantern resealing jobs come in between £245 and £495 ex VAT (£294–£594 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?
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 Bangor, Gwynedd: questions
Do you need to visit to price roof lantern resealing?
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.
Can you repair a lantern someone else installed in Bangor, Gwynedd?
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.
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.
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.
Other lantern repairs in Bangor, Gwynedd
- Glazing bar and capping repairs in Bangor, Gwynedd
- Ridge and hip repairs in Bangor, Gwynedd
- Eaves beam and gutter repairs in Bangor, Gwynedd
- Slipped glass panel repairs in Bangor, Gwynedd
- Solar control and self-cleaning glass upgrades in Bangor, Gwynedd
- Flat rooflight and skylight repairs in Bangor, Gwynedd
Roof lantern resealing near Bangor, Gwynedd
More about roof lantern resealing · All roof lantern repairs in Bangor, Gwynedd