In Chepstow, as everywhere, condensation forms when warm, humid air meets a cold surface — and a roof lantern is the coldest surface in many kitchens. Send photos and we'll tell you what we think has failed.

Is it time for condensation diagnosis and fixes?
- Water on the inside of the glass on cold mornings, even without rain
- Drips after cooking, showers or drying clothes
- Black mould at the base of the lantern lining
Why it happens
High humidity
Cooking, kettles, showers, drying washing and people all add moisture to the air.
Cold surfaces
Older glass, uninsulated kerbs and un-thermally-broken frames stay cold and collect condensation.
Roof lanterns in Chepstow
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 Chepstow as part of Gwent, about 14 miles from Newport, Gwent.
Close by, we also cover Monmouth (12 miles), Newport, Gwent (14 miles), Cwmbran (15 miles).
Guide prices for condensation diagnosis and fixes in Chepstow
Typical range: £145–£495 ex VAT, which is £174–£594 with VAT, per visit. 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?
In Wales, like-for-like repairs to a roof lantern don't usually involve building control. A full replacement or a bigger opening is controlled under the Building Regulations 2010 (as applied in Wales), so we set out the route in writing first. 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.
Condensation diagnosis and fixes in Chepstow: questions
How do I get a price for condensation diagnosis and fixes in Chepstow?
Send a few photos of the lantern and the problem, with your Chepstow postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Can you repair a lantern someone else installed in Chepstow?
Yes. We repair lanterns whoever fitted them. If yours is still under the installer's warranty, contact them first so you don't affect it.
What does a condensation visit cost?
Diagnosis visits start from £145 ex VAT. Any fixes are priced separately and confirmed in writing before work starts.
Is condensation in a lantern normal?
Occasional light condensation on very cold mornings can be. Regular dripping isn't, and can damage linings and cause mould.
Other lantern repairs in Chepstow
- Roof lantern resealing in Chepstow
- Eaves beam and gutter repairs in Chepstow
- Upstand and kerb repairs in Chepstow
- Flat roof junction and flashing repairs in Chepstow
- Leak investigation and inspection in Chepstow
- Orangery lantern repairs in Chepstow
Condensation diagnosis and fixes near Chepstow
More about condensation diagnosis and fixes · All roof lantern repairs in Chepstow