We carry out condensation diagnosis and fixes in Monmouth and across the NP25 area. Condensation forms when warm, humid air meets a cold surface — and a roof lantern is the coldest surface in many kitchens.

What you might be seeing
- Water on the inside of the glass on cold mornings, even without rain
- Black mould at the base of the lantern lining
- Wet window sills elsewhere in the house too
What usually causes it?
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.
Covering Monmouth and nearby
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 Monmouth is roughly 20 miles — all part of the Gwent area we cover.
If you're just outside Monmouth, we also cover Chepstow (12 miles), Abergavenny (13 miles), Pontypool (16 miles).
What should you expect to pay in Monmouth?
Guide price for condensation diagnosis and fixes: £145–£495 ex VAT (£174–£594 inc 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?
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.
Condensation diagnosis and fixes in Monmouth: questions
Do you cover Monmouth?
Yes. We cover Monmouth, including the NP25 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 condensation diagnosis and fixes?
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.
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 Monmouth
- Glazing bar and capping repairs in Monmouth
- Eaves beam and gutter repairs in Monmouth
- Flat roof junction and flashing repairs in Monmouth
- Solar control and self-cleaning glass upgrades in Monmouth
- Opening vent and actuator repairs in Monmouth
- Cleaning and maintenance in Monmouth
Condensation diagnosis and fixes near Monmouth
More about condensation diagnosis and fixes · All roof lantern repairs in Monmouth