Condensation forms when warm, humid air meets a cold surface — and a roof lantern is the coldest surface in many kitchens. We carry out condensation diagnosis and fixes across Greater London, with a guide price from your photos and a fixed price in writing before any work starts.

Signs you need condensation diagnosis and fixes
- 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.
Roof lanterns in Greater London
Even in drier areas, one heavy downpour with blocked eaves is enough to overflow a lantern indoors. Clearing the eaves channel is the simplest prevention there is.
Across London, many lanterns sit on rear extensions with access only through the house, so we protect floors and plan the work to keep time indoors to a minimum. Parking and any permits are factored into the quote.
- Westminster
- Islington
- Bexley
- Barking
- Archway
- Sutton
- Croydon
- Ilford
- Enfield
- Harrow
- Tottenham
- Walthamstow
- Dagenham
- Becontree
- Romford
- Hayes
- Wembley
- Fulham
- Edmonton
- Southall
- Putney
- Battersea
- Canary Wharf
- Purley
- Peckham
- Chingford
- Uxbridge
- Wimbledon
- Stamford Hill
- Brixton
- Hounslow
- Finchley
- Cricklewood
- Mitcham
- Feltham
- Acton
- Beckenham
- Chelsea
- Streatham
- South Croydon
- Leytonstone
- Eltham
- Morden
- Carshalton
- Catford
- Willesden
- Canning Town
- Holloway
- Welling
- Shepherds Bush
- Surbiton
- Greenford
- Heston
- Stratford
- Chiswick
- Thamesmead
- Ruislip
- Greenwich
- Barnet
- Kilburn
- Wood Green
- Muswell Hill
- Bow
- Highbury
- Camden Town
- Northolt
- Coulsdon
- Hornchurch
- Blackheath
- Isleworth
- Chalk Farm
- New Malden
- Hanworth
- Woodford Green
- Richmond
- Barnes
- Notting Hill
- Wallington
- Pimlico
- Hampton
What should you expect to pay for condensation diagnosis and fixes in Greater London?
Most condensation diagnosis and fixes jobs come in between £145 and £495 ex VAT (£174–£594 including 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 England?
Most lantern repairs in England need no approval at all. Where a job turns into a replacement, the Building Regulations 2010 apply and we confirm how the work will be signed off before we start. Listed buildings need listed building consent from the local council for alterations, and conservation areas can have extra controls; like-for-like repairs are treated differently from changes, so check with the council's conservation officer first.
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 Greater London: questions
Will new glass stop condensation?
Better glass raises the inner surface temperature and helps, but if the room is very humid, ventilation matters more. We'll tell you which will make the bigger difference.
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.
Which towns in Greater London do you cover?
All of Greater London, including Westminster, Islington, Bexley, Barking, Archway, Sutton. Rural and remote addresses are covered by arrangement.
How do I get a price for condensation diagnosis and fixes in Greater London?
Send a few photos of the lantern and the problem with your postcode, by WhatsApp or the form. We reply with a guide price and confirm the fixed price in writing before any work starts.
Other repairs in Greater London
- Roof lantern leak repairs in Greater London
- Opening vent and actuator repairs in Greater London
- Flat rooflight and skylight repairs in Greater London
- Leak investigation and inspection in Greater London
- Cleaning and maintenance in Greater London
- Commercial roof lantern repairs in Greater London
Nearby areas
- Condensation diagnosis and fixes in Surrey
- Condensation diagnosis and fixes in Hertfordshire
- Condensation diagnosis and fixes in Buckinghamshire
- Condensation diagnosis and fixes in Essex
- Condensation diagnosis and fixes in Berkshire
More about condensation diagnosis and fixes · All roof lantern repairs in Greater London