The junction where the flat roof covering meets the lantern kerb is a weak point on many extensions. We carry out flat roof junction and flashing repairs across West Sussex, with a guide price from your photos and a fixed price in writing before any work starts.

Signs you need flat roof junction and flashing repairs
- Leak near the lantern but not from the frame
- Missing or loose edge trims and flashings
- Ponding on the roof next to the lantern
What usually causes it?
Unbonded membrane
EPDM or single-ply that has come away from the kerb lets water run behind it.
Cracked GRP
Fibreglass roofs can crack at the kerb corner where movement concentrates.
Roof lanterns in West Sussex
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.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
What should you expect to pay for flat roof junction and flashing repairs in West Sussex?
Guide price for flat roof junction and flashing repairs: £245–£695 ex VAT (£294–£834 inc VAT), per lantern. 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.
Flat roof junction and flashing repairs in West Sussex: questions
Do you repair the whole flat roof?
We repair the area around the lantern. If the wider roof is failing we'll tell you and can quote, but we won't push a new roof if a local repair will do.
What does a junction repair cost?
Usually £245–£695 ex VAT, confirmed in writing before work starts.
Which towns in West Sussex do you cover?
All of West Sussex, including Chichester, Crawley, Worthing, Bognor Regis, Littlehampton, Horsham. Rural and remote addresses are covered by arrangement.
How do I get a price for flat roof junction and flashing repairs in West Sussex?
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 West Sussex
- Upstand and kerb repairs in West Sussex
- Solar control and self-cleaning glass upgrades in West Sussex
- Timber roof lantern repairs in West Sussex
- Opening vent and actuator repairs in West Sussex
- Leak investigation and inspection in West Sussex
- Roof lantern replacement in West Sussex
Nearby areas
- Flat roof junction and flashing repairs in East Sussex
- Flat roof junction and flashing repairs in Surrey
- Flat roof junction and flashing repairs in Hampshire
- Flat roof junction and flashing repairs in Greater London
- Flat roof junction and flashing repairs in Berkshire
More about flat roof junction and flashing repairs · All roof lantern repairs in West Sussex