In Runcorn, as everywhere, the junction where the flat roof covering meets the lantern kerb is a weak point on many extensions. Send photos and we'll tell you what we think has failed.

Signs you need flat roof junction and flashing repairs
- Leak near the lantern but not from the frame
- Splits, blisters or lifted edges in the roof covering by the kerb
- Ponding on the roof next to the lantern
Common causes we find
Unbonded membrane
EPDM or single-ply that has come away from the kerb lets water run behind it.
Missing trims
Without a trim or flashing to protect the top edge, water gets in behind the membrane.
About Runcorn and the WA7 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.
From Chester to Runcorn is roughly 12 miles — all part of the Cheshire area we cover.
If you're just outside Runcorn, we also cover Widnes (1 mile), Halewood (4 miles), Huyton (7 miles).
Guide prices for flat roof junction and flashing repairs in Runcorn
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?
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.
Flat roof junction and flashing repairs in Runcorn: questions
Do you cover Runcorn?
Yes. We cover Runcorn, including the WA7 postcode area, as part of Cheshire. 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 Runcorn?
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 junction repair cost?
Usually £245–£695 ex VAT, confirmed in writing before work starts.
Can you repair a GRP roof without it showing?
Repairs are colour-matched as closely as possible, but new topcoat next to weathered topcoat can look slightly different at first.
Other lantern repairs in Runcorn
- Eaves beam and gutter repairs in Runcorn
- Slipped glass panel repairs in Runcorn
- Opening vent and actuator repairs in Runcorn
- Flat rooflight and skylight repairs in Runcorn
- Leak investigation and inspection in Runcorn
- Cleaning and maintenance in Runcorn
Flat roof junction and flashing repairs near Runcorn
More about flat roof junction and flashing repairs · All roof lantern repairs in Runcorn