In Lerwick, 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.

What you might be seeing
- Drips after cooking, showers or drying clothes
- 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.
Poor ventilation
Without trickle vents, extraction or an opening vent, moist air has nowhere to go.
About Lerwick and the ZE1 area
Wind-driven rain is the real test of a roof lantern, and the wetter west sees plenty of it. Leaks that appear only in a storm from one direction usually point to the cappings or eaves on that face — a useful clue when you send us photos.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
We cover Lerwick by arrangement: island work is planned around ferry access, and any travel or access costs are set out in your written quote before you commit.
Guide prices for condensation diagnosis and fixes in Lerwick
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 Scotland?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Scotland. Replacing the whole lantern or enlarging the opening is different and falls under the Building (Scotland) Regulations 2004; we confirm in writing which route applies before any replacement. Listed buildings in Scotland need listed building consent from the planning authority for alterations, with Historic Environment Scotland guidance; check 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 Lerwick: questions
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.
Can you repair a lantern someone else installed in Lerwick?
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.
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.
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.
Other lantern repairs in Lerwick
- Roof lantern resealing in Lerwick
- Aluminium roof lantern repairs in Lerwick
- uPVC roof lantern repairs in Lerwick
- Roof lantern respraying in Lerwick
- Flat rooflight and skylight repairs in Lerwick
- Leak investigation and inspection in Lerwick
More about condensation diagnosis and fixes · All roof lantern repairs in Lerwick