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 Cardiff (CF10) and we'll tell you which it is — with the price agreed in writing before any work.
Signs you need 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
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.
Movement and age
Thermal movement and age wear the seal; units at the bottom of the lantern often go first.
About Cardiff and the CF10 area
Western and upland parts of the UK get more rain and more wind-driven rain than the east, and that's what finds weak cappings and blocked eaves first. Lanterns here benefit from a check of the bars on the most exposed face and a clear eaves channel before winter.
If you're just outside Cardiff, we also cover Penarth (3 miles), Caerphilly (7 miles), Barry (7 miles).
Guide prices for misted glass unit replacement in Cardiff
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 Wales?
Most lantern repairs in Wales need no approval at all. Where a job turns into a replacement, the Building Regulations 2010 (as applied in Wales) apply and we confirm how the work will be signed off before we start. Listed buildings in Wales need listed building consent from the local planning authority for alterations, with Cadw guidance on historic buildings; check with the council before changing a lantern on a listed property.
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 Cardiff: 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 Cardiff do you cover?
As well as Cardiff, we cover nearby Penarth, Caerphilly, Barry, Risca and the rest of South Glamorgan.
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 Cardiff
- Flat roof junction and flashing repairs in Cardiff
- Slipped glass panel repairs in Cardiff
- Condensation diagnosis and fixes in Cardiff
- Timber roof lantern repairs in Cardiff
- Opening vent and actuator repairs in Cardiff
- Roof lantern respraying in Cardiff
Misted glass unit replacement near Cardiff
More about misted glass unit replacement · All roof lantern repairs in Cardiff