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 Welwyn Garden City (AL8) 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
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.
Covering Welwyn Garden City and nearby
Most inland lantern leaks aren't storm damage; they're usually tired sealant, a lifted capping or blocked eaves drainage. All three are quick to find and fix once you know where to look.
From St Albans to Welwyn Garden City is roughly 6 miles — all part of the Hertfordshire area we cover.
We also cover nearby Hatfield (3 miles), Hertford (6 miles), St Albans (6 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 Welwyn Garden City: 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.
Which places near Welwyn Garden City do you cover?
As well as Welwyn Garden City, we cover nearby Hatfield, Hertford, St Albans, Harpenden and the rest of Hertfordshire.
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 Welwyn Garden City
- Roof lantern leak repairs in Welwyn Garden City
- Glazing bar and capping repairs in Welwyn Garden City
- Eaves beam and gutter repairs in Welwyn Garden City
- Cracked lantern glass replacement in Welwyn Garden City
- Slipped glass panel repairs in Welwyn Garden City
- Commercial roof lantern repairs in Welwyn Garden City
Roof lantern resealing near Welwyn Garden City
More about roof lantern resealing · All roof lantern repairs in Welwyn Garden City