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 Derry~Londonderry (BT47) 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
- Misting that comes and goes with the weather
Common causes we find
Water sitting on the edge
If the unit's edge sits in water because the eaves don't drain, the seal fails sooner.
Movement and age
Thermal movement and age wear the seal; units at the bottom of the lantern often go first.
Covering Derry~Londonderry and nearby
Damp, mild winters keep moss and algae growing on flat roofs and lantern frames, which holds water against seals and blocks weep slots. Regular clearing makes a real difference in wetter areas.
Neighbouring places we cover include Strabane (14 miles), Limavady (15 miles), Portstewart (27 miles).
How much should it cost?
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 Northern Ireland?
Most lantern repairs in Northern Ireland need no approval at all. Where a job turns into a replacement, the Building Regulations (Northern Ireland) 2012 apply and we confirm how the work will be signed off before we start. Listed buildings in Northern Ireland need listed building consent from the council for alterations; check with the council's planning service 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 Derry~Londonderry: questions
Do you cover Derry~Londonderry?
Yes. We cover Derry~Londonderry, including the BT47 postcode area, as part of County Londonderry. Send photos by WhatsApp or the form for a free guide price, and we'll confirm the fixed price in writing before any work starts.
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.
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