If a roof lantern pane looks cloudy or wet between the two layers of glass, the sealed unit has failed and moisture has got inside. Send photos from Eltham (SE9) and we'll tell you which it is — with the price agreed in writing before any work.

Is it time for misted glass unit replacement?
- Fog, droplets or white bloom between the panes
- One pane looks hazier than the others
- Water marks or tide lines inside the unit
Common causes we find
Edge seal failure
Every sealed unit has an edge seal and desiccant. Once the seal fails, humid air gets in and the desiccant saturates.
Water sitting on the edge
If the unit's edge sits in water because the eaves don't drain, the seal fails sooner.
Roof lanterns in Eltham
Drier, sunnier parts of the UK are kinder to seals than the wet west, but strong sun ages sealant, gaskets and plastic end caps, and south- or west-facing lanterns can make rooms very warm. Solar control glass and an opening vent help.
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.
Eltham is around 9 miles from Westminster, and both are within our Greater London coverage.
Close by, we also cover Blackheath (2 miles), Welling (3 miles), Catford (3 miles).
Guide prices for misted glass unit replacement in Eltham
Typical range: £245–£595 ex VAT, which is £294–£714 with VAT, per glass unit. 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.
Misted glass unit replacement in Eltham: questions
Can you repair a lantern someone else installed in Eltham?
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.
Which places near Eltham do you cover?
As well as Eltham, we cover nearby Blackheath, Welling, Catford, Greenwich and the rest of Greater London.
How much does a misted lantern unit cost to replace?
Usually £245–£595 ex VAT per unit depending on size, glass spec and access, confirmed in writing before work starts.
Will the new pane match the others?
We match tint and coatings as closely as possible; a new unit can look very slightly clearer than older neighbours.
Other lantern repairs in Eltham
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- Roof lantern respraying in Eltham
- Roof lantern replacement in Eltham
Misted glass unit replacement near Eltham
More about misted glass unit replacement · All roof lantern repairs in Eltham