A roof lantern leak is almost always a failed seal, a lifted capping, blocked eaves drainage or a problem where the kerb meets the flat roof — not a failed lantern. Send photos from Cwmbran (NP44) and we'll tell you which it is — with the price agreed in writing before any work.

Is it time for roof lantern leak repairs?
- Brown staining or bubbling paint on the plasterboard lining around the lantern
- Damp patches on the ceiling a short distance from the lantern
- A leak that only appears in wind-driven rain from one direction
What usually causes it?
Lifted or misaligned cappings
Top cappings clip or screw over each glazing bar. If one has lifted, been knocked or was never seated, rain gets straight under it.
The kerb or roof junction
If the flat roof membrane isn't dressed high enough up the kerb, or the kerb has no fall, water sits against the joint and finds its way in under the lantern.
About Cwmbran and the NP44 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.
From Newport, Gwent to Cwmbran is roughly 5 miles — all part of the Gwent area we cover.
If you're just outside Cwmbran, we also cover Pontypool (3 miles), Risca (5 miles), Newport, Gwent (5 miles).
How much should it cost?
Guide price for roof lantern leak repairs: £195–£595 ex VAT (£234–£714 inc VAT), per lantern. 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.
Roof lantern leak repairs in Cwmbran: questions
Do you cover Cwmbran?
Yes. We cover Cwmbran, including the NP44 postcode area, as part of Gwent. 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 roof lantern leak repairs?
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 roof lantern leak repair cost?
Most leak repairs fall between £195 and £595 ex VAT for a standard lantern with ladder access. The fixed price is confirmed in writing before any work starts.
Do I need to be home?
If we need to water-test or check the inside of the lantern, yes. Exterior-only work can sometimes be done with access arranged in advance.
Other lantern repairs in Cwmbran
- Upstand and kerb repairs in Cwmbran
- Cracked lantern glass replacement in Cwmbran
- Solar control and self-cleaning glass upgrades in Cwmbran
- Timber roof lantern repairs in Cwmbran
- Leak investigation and inspection in Cwmbran
- Cleaning and maintenance in Cwmbran
Roof lantern leak repairs near Cwmbran
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