We carry out misted glass unit replacement in Rhondda and across the CF42 area. 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.

What you might be seeing
- One pane looks hazier than the others
- Misting that comes and goes with the weather
- Water marks or tide lines inside the unit
What usually causes it?
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.
Roof lanterns in Rhondda
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.
We cover Rhondda as part of Mid Glamorgan, about 12 miles from Bridgend.
Neighbouring places we cover include Tonypandy (3 miles), Aberdare (4 miles), Pontypridd (6 miles).
What should you expect to pay in Rhondda?
Guide price for misted glass unit replacement: £245–£595 ex VAT (£294–£714 inc 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 Rhondda: questions
How do I get a price for misted glass unit replacement in Rhondda?
Send a few photos of the lantern and the problem, with your Rhondda postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
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.
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.
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.
Other lantern repairs in Rhondda
- Upstand and kerb repairs in Rhondda
- Condensation diagnosis and fixes in Rhondda
- uPVC roof lantern repairs in Rhondda
- Opening vent and actuator repairs in Rhondda
- Flat rooflight and skylight repairs in Rhondda
- Commercial roof lantern repairs in Rhondda
Misted glass unit replacement near Rhondda
More about misted glass unit replacement · All roof lantern repairs in Rhondda