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 Carshalton (SM5) and we'll tell you which it is — with the price agreed in writing before any work.
Is it time for 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
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.
Roof lanterns in Carshalton
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.
Across London, many lanterns sit on rear extensions with access only through the house, so we protect floors and plan the work to keep time indoors to a minimum. Parking and any permits are factored into the quote.
We cover Carshalton as part of Greater London, about 9 miles from Westminster.
If you're just outside Carshalton, we also cover Wallington (1 mile), Sutton (2 miles), Mitcham (2 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 Carshalton: questions
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.
Can you repair a lantern someone else installed in Carshalton?
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.
How long does resealing take?
Most domestic lanterns take a few hours in dry weather.
Other lantern repairs in Carshalton
- Eaves beam and gutter repairs in Carshalton
- Solar control and self-cleaning glass upgrades in Carshalton
- Opening vent and actuator repairs in Carshalton
- Roof lantern respraying in Carshalton
- Leak investigation and inspection in Carshalton
- Cleaning and maintenance in Carshalton
Roof lantern resealing near Carshalton
More about roof lantern resealing · All roof lantern repairs in Carshalton