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 Surbiton (KT5) and we'll tell you which it is — with the price agreed in writing before any work.

Signs you need roof lantern resealing
- Cracked, split or shrunken sealant along the bars
- Sealant applied over sealant from previous patch repairs
- A lantern that is 8–15 years old and has never been maintained
Why it happens
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.
Wrong product used
General-purpose or acetoxy silicone can fail early on some frames and coatings. Glazing joints need a low-modulus, compatible sealant.
Roof lanterns in Surbiton
Even in drier areas, one heavy downpour with blocked eaves is enough to overflow a lantern indoors. Clearing the eaves channel is the simplest prevention there is.
London's extensions are often tight to neighbouring walls and roofs. Where a repair needs access over a neighbour's property, we'll tell you in advance so you can arrange it.
From Westminster to Surbiton is roughly 10 miles — all part of the Greater London area we cover.
If you're just outside Surbiton, we also cover New Malden (2 miles), Esher (3 miles), Hampton (3 miles).
How much should it cost?
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 England?
Most lantern repairs in England need no approval at all. Where a job turns into a replacement, the Building Regulations 2010 apply and we confirm how the work will be signed off before we start. 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 Surbiton: questions
Do you cover Surbiton?
Yes. We cover Surbiton, including the KT5 postcode area, as part of Greater London. 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.
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.
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 Surbiton
- Upstand and kerb repairs in Surbiton
- Slipped glass panel repairs in Surbiton
- Condensation diagnosis and fixes in Surbiton
- Timber roof lantern repairs in Surbiton
- uPVC roof lantern repairs in Surbiton
- Leak investigation and inspection in Surbiton
Roof lantern resealing near Surbiton
More about roof lantern resealing · All roof lantern repairs in Surbiton