Condensation forms when warm, humid air meets a cold surface — and a roof lantern is the coldest surface in many kitchens. Send photos from Grantham (NG31) and we'll tell you which it is — with the price agreed in writing before any work.

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
Cold surfaces
Older glass, uninsulated kerbs and un-thermally-broken frames stay cold and collect condensation.
Poor ventilation
Without trickle vents, extraction or an opening vent, moist air has nowhere to go.
Covering Grantham and nearby
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.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
We cover Grantham as part of Lincolnshire, about 22 miles from Lincoln.
If you're just outside Grantham, we also cover Newark-on-Trent (13 miles), Melton Mowbray (14 miles), Oakham (17 miles).
How much should it cost?
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 England?
In England, 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, so we set out the route in writing first. 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 Grantham: questions
How do I get a price for condensation diagnosis and fixes in Grantham?
Send a few photos of the lantern and the problem, with your Grantham 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 Grantham?
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 Grantham
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Condensation diagnosis and fixes near Grantham
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