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 Borehamwood (WD6) 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?
- One pane looks hazier than the others
- Misting that comes and goes with the weather
- Water marks or tide lines inside the unit
Why it happens
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.
About Borehamwood and the WD6 area
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 Borehamwood is roughly 7 miles — all part of the Hertfordshire area we cover.
Close by, we also cover Barnet (3 miles), Bushey (4 miles), Potters Bar (5 miles).
Guide prices for misted glass unit replacement in Borehamwood
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?
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.
Misted glass unit replacement in Borehamwood: questions
Do you need to visit to price misted glass unit replacement?
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 Borehamwood do you cover?
As well as Borehamwood, we cover nearby Barnet, Bushey, Potters Bar, Watford and the rest of Hertfordshire.
How long does a replacement unit take?
Units are made to measure, so there's a lead time between measuring and fitting. Fitting itself is usually a short visit.
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 Borehamwood
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- Orangery lantern repairs in Borehamwood
- Commercial roof lantern repairs in Borehamwood
Misted glass unit replacement near Borehamwood
More about misted glass unit replacement · All roof lantern repairs in Borehamwood