We carry out roof lantern resealing in Denbigh and across the LL16 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.

Is it time for roof lantern resealing?
- Cracked, split or shrunken sealant along the bars
- Several small leaks rather than one obvious one
- A lantern that is 8–15 years old and has never been maintained
What usually causes it?
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.
Covering Denbigh and nearby
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.
From Wrexham to Denbigh is roughly 20 miles — all part of the Clwyd area we cover.
Neighbouring places we cover include Ruthin (6 miles), Abergele (10 miles), Rhyl (10 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?
In Wales, like-for-like repairs to a roof lantern don't usually involve building control. A full replacement or a bigger opening is controlled under the Building Regulations 2010 (as applied in Wales), so we set out the route in writing first. 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 Denbigh: questions
How do I get a price for roof lantern resealing in Denbigh?
Send a few photos of the lantern and the problem, with your Denbigh postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Can you repair a lantern someone else installed in Denbigh?
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 Denbigh
- Ridge and hip repairs in Denbigh
- Upstand and kerb repairs in Denbigh
- Flat roof junction and flashing repairs in Denbigh
- Misted glass unit replacement in Denbigh
- Slipped glass panel repairs in Denbigh
- Urgent leak make-safe in Denbigh
Roof lantern resealing near Denbigh
More about roof lantern resealing · All roof lantern repairs in Denbigh