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 Chester-le-Street (DH3) and we'll tell you which it is — with the price agreed in writing before any work.

What you might be seeing
- Cracked, split or shrunken sealant along the bars
- Black mould or dirt lines trapped in old silicone
- A lantern that is 8–15 years old and has never been maintained
Why it happens
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 Chester-le-Street
Snow and ice sitting at the eaves can block a lantern's drainage and push water back under the glass as it melts. If your lantern leaks after a thaw rather than after rain, tell us — it points to the eaves and kerb.
Chester-le-Street is around 6 miles from Durham, and both are within our County Durham coverage.
Close by, we also cover Washington (4 miles), Houghton-le-Spring (5 miles), Stanley (5 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?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in England. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010; we confirm in writing which route applies before any replacement. 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 Chester-le-Street: questions
Do you cover Chester-le-Street?
Yes. We cover Chester-le-Street, including the DH3 postcode area, as part of County Durham. 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 Chester-le-Street
- Eaves beam and gutter repairs in Chester-le-Street
- Flat roof junction and flashing repairs in Chester-le-Street
- Misted glass unit replacement in Chester-le-Street
- Condensation diagnosis and fixes in Chester-le-Street
- Roof lantern respraying in Chester-le-Street
- Cleaning and maintenance in Chester-le-Street
Roof lantern resealing near Chester-le-Street
More about roof lantern resealing · All roof lantern repairs in Chester-le-Street