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 Dumbarton (G82) and we'll tell you which it is — with the price agreed in writing before any work.

Is it time for roof lantern resealing?
- Black mould or dirt lines trapped in old silicone
- 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.
About Dumbarton and the G82 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.
Urban grime and traffic film dull glass and frames quickly; a clean and seal check makes a tired lantern look and perform much better.
We cover Dumbarton as part of Glasgow and Clyde, about 13 miles from Glasgow.
Neighbouring places we cover include Clydebank (7 miles), Greenock (7 miles), Helensburgh (7 miles).
What should you expect to pay in Dumbarton?
Guide price for roof lantern resealing: £245–£495 ex VAT (£294–£594 inc 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 Scotland?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Scotland. Replacing the whole lantern or enlarging the opening is different and falls under the Building (Scotland) Regulations 2004; we confirm in writing which route applies before any replacement. Listed buildings in Scotland need listed building consent from the planning authority for alterations, with Historic Environment Scotland guidance; check 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 Dumbarton: questions
Can you repair a lantern someone else installed in Dumbarton?
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.
Which places near Dumbarton do you cover?
As well as Dumbarton, we cover nearby Clydebank, Greenock, Helensburgh, Johnstone and the rest of Glasgow and Clyde.
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.
Other lantern repairs in Dumbarton
- Glazing bar and capping repairs in Dumbarton
- Cracked lantern glass replacement in Dumbarton
- Opening vent and actuator repairs in Dumbarton
- Cleaning and maintenance in Dumbarton
- Roof lantern replacement in Dumbarton
- Commercial roof lantern repairs in Dumbarton
Roof lantern resealing near Dumbarton
More about roof lantern resealing · All roof lantern repairs in Dumbarton