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 Monmouth (NP25) 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?
- Water running down the inside face of the glass
- 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?
Failed silicone or glazing tape
UV and thermal movement break down the seal between capping, gasket and glass. Once a gap opens, water tracks along the bar and drops at the lowest point.
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.
About Monmouth and the NP25 area
Wind-driven rain is the real test of a roof lantern, and the wetter west sees plenty of it. Leaks that appear only in a storm from one direction usually point to the cappings or eaves on that face — a useful clue when you send us photos.
We cover Monmouth as part of Gwent, about 20 miles from Newport, Gwent.
Neighbouring places we cover include Chepstow (12 miles), Abergavenny (13 miles), Pontypool (16 miles).
How much should it cost?
Most roof lantern leak repairs jobs come in between £195 and £595 ex VAT (£234–£714 including 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?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Wales. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010 (as applied in Wales); we confirm in writing which route applies before any replacement. 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 Monmouth: questions
How do I get a price for roof lantern leak repairs in Monmouth?
Send a few photos of the lantern and the problem, with your Monmouth 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 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.
Can you fix the leak in the rain?
We can make the lantern safe in wet weather, but sealants and tapes need a dry, clean surface to bond, so permanent repairs are done in a dry window.
Will you show me what was wrong?
Yes. We photograph the failed detail and the finished repair and send them to you with the invoice.
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