We carry out roof lantern resealing in Helensburgh and across the G84 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?
- Black mould or dirt lines trapped in old silicone
- Several small leaks rather than one obvious one
- A lantern that is 8–15 years old and has never been maintained
Common causes we find
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.
Roof lanterns in Helensburgh
Western and upland parts of the UK get more rain and more wind-driven rain than the east, and that's what finds weak cappings and blocked eaves first. Lanterns here benefit from a check of the bars on the most exposed face and a clear eaves channel before winter.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
We cover Helensburgh as part of Argyll and Bute, about 40 miles from Oban.
We also cover nearby Greenock (4 miles), Dumbarton (7 miles), Dunoon (9 miles).
How much should it cost?
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 Scotland?
Most lantern repairs in Scotland need no approval at all. Where a job turns into a replacement, the Building (Scotland) Regulations 2004 apply and we confirm how the work will be signed off before we start. 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 Helensburgh: questions
How do I get a price for roof lantern resealing in Helensburgh?
Send a few photos of the lantern and the problem, with your Helensburgh postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Which places near Helensburgh do you cover?
As well as Helensburgh, we cover nearby Greenock, Dumbarton, Dunoon, Clydebank and the rest of Argyll and Bute.
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.
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Roof lantern resealing near Helensburgh
More about roof lantern resealing · All roof lantern repairs in Helensburgh