The junction where the flat roof covering meets the lantern kerb is a weak point on many extensions. Send photos from Porthmadog (LL49) and we'll tell you which it is — with the price agreed in writing before any work.
What you might be seeing
- Leak near the lantern but not from the frame
- Splits, blisters or lifted edges in the roof covering by the kerb
- Missing or loose edge trims and flashings
What usually causes it?
Cracked GRP
Fibreglass roofs can crack at the kerb corner where movement concentrates.
Missing trims
Without a trim or flashing to protect the top edge, water gets in behind the membrane.
About Porthmadog and the LL49 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.
Porthmadog is around 21 miles from Bangor, Gwynedd, and both are within our Gwynedd coverage.
Close by, we also cover Pwllheli (12 miles), Caernarfon (16 miles), Dolgellau (16 miles).
Guide prices for flat roof junction and flashing repairs in Porthmadog
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 Wales?
Most lantern repairs in Wales need no approval at all. Where a job turns into a replacement, the Building Regulations 2010 (as applied in Wales) apply and we confirm how the work will be signed off before we start. Listed buildings in Wales need listed building consent from the local planning authority for alterations, with Cadw guidance on historic buildings; check with the council 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.
Flat roof junction and flashing repairs in Porthmadog: questions
Do you need to visit to price flat roof junction and flashing repairs?
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 Porthmadog?
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.
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.
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 Porthmadog
- Roof lantern leak repairs in Porthmadog
- Ridge and hip repairs in Porthmadog
- Eaves beam and gutter repairs in Porthmadog
- uPVC roof lantern repairs in Porthmadog
- Roof lantern respraying in Porthmadog
- Leak investigation and inspection in Porthmadog
Flat roof junction and flashing repairs near Porthmadog
More about flat roof junction and flashing repairs · All roof lantern repairs in Porthmadog