In Portsmouth, 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
- Wet window sills elsewhere in the house too
Why it happens
High humidity
Cooking, kettles, showers, drying washing and people all add moisture to the air.
Poor ventilation
Without trickle vents, extraction or an opening vent, moist air has nowhere to go.
About Portsmouth and the PO5 area
Drier, sunnier parts of the UK are kinder to seals than the wet west, but strong sun ages sealant, gaskets and plastic end caps, and south- or west-facing lanterns can make rooms very warm. Solar control glass and an opening vent help.
Portsmouth is around 15 miles from Southampton, and both are within our Hampshire coverage.
We also cover nearby Gosport (2 miles), Fareham (5 miles), Ryde (6 miles).
What should you expect to pay in Portsmouth?
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 England?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in England. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010; we confirm in writing which route applies before any replacement. 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 Portsmouth: questions
Do you cover Portsmouth?
Yes. We cover Portsmouth, including the PO5 postcode area, as part of Hampshire. 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.
Can you repair a lantern someone else installed in Portsmouth?
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.
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Condensation diagnosis and fixes near Portsmouth
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