We carry out roof lantern resealing in Horsham and across the RH12 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
- Black mould or dirt lines trapped in old silicone
- Several small leaks rather than one obvious one
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.
Covering Horsham and nearby
Sun and UV do more damage than rain on many lanterns here: brittle ridge caps, chalky finishes and hardened gaskets. They're cheap to replace before they let water in.
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.
Horsham is around 25 miles from Chichester, and both are within our West Sussex coverage.
Neighbouring places we cover include Crawley (7 miles), Horley (11 miles), Haywards Heath (11 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 England?
In England, 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, so we set out the route in writing first. Listed buildings need listed building consent from the local council for alterations, and conservation areas can have extra controls; like-for-like repairs are treated differently from changes, so check with the council's conservation officer first.
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 Horsham: questions
Do you cover Horsham?
Yes. We cover Horsham, including the RH12 postcode area, as part of West Sussex. Send photos by WhatsApp or the form for a free guide price, and we'll confirm the fixed price in writing before any work starts.
Can you repair a lantern someone else installed in Horsham?
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 Horsham
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- Flat rooflight and skylight repairs in Horsham
Roof lantern resealing near Horsham
More about roof lantern resealing · All roof lantern repairs in Horsham