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 Watford (WD17) and we'll tell you which it is — with the price agreed in writing before any work.
Is it time for roof lantern resealing?
- Black mould or dirt lines trapped in old silicone
- Several small leaks rather than one obvious one
- A lantern that is 8–15 years old and has never been maintained
Common causes we find
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 Watford
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 Watford is roughly 7 miles — all part of the Hertfordshire area we cover.
If you're just outside Watford, we also cover Bushey (2 miles), Rickmansworth (4 miles), Borehamwood (5 miles).
How much should it cost?
Most roof lantern resealing jobs come in between £245 and £495 ex VAT (£294–£594 including 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 Watford: questions
How do I get a price for roof lantern resealing in Watford?
Send a few photos of the lantern and the problem, with your Watford postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Can you repair a lantern someone else installed in Watford?
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 Watford
- Roof lantern leak repairs in Watford
- Flat roof junction and flashing repairs in Watford
- Misted glass unit replacement in Watford
- Cracked lantern glass replacement in Watford
- Flat rooflight and skylight repairs in Watford
- Cleaning and maintenance in Watford
Roof lantern resealing near Watford
More about roof lantern resealing · All roof lantern repairs in Watford