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 Mid Glamorgan, 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
- Splits, blisters or lifted edges in the roof covering by the kerb
- Missing or loose edge trims and flashings
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 Mid Glamorgan
Damp, mild winters keep moss and algae growing on flat roofs and lantern frames, which holds water against seals and blocks weep slots. Regular clearing makes a real difference in wetter areas.
What should you expect to pay for flat roof junction and flashing repairs in Mid Glamorgan?
Typical range: £245–£695 ex VAT, which is £294–£834 with 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?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Wales. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010 (as applied in Wales); we confirm in writing which route applies before any replacement. 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 Mid Glamorgan: questions
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.
Which towns in Mid Glamorgan do you cover?
All of Mid Glamorgan, including Bridgend, Rhondda, Tonypandy, Merthyr Tydfil, Pontypridd, Aberdare. Rural and remote addresses are covered by arrangement.
How do I get a price for flat roof junction and flashing repairs in Mid Glamorgan?
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 Mid Glamorgan
- Roof lantern leak repairs in Mid Glamorgan
- Roof lantern resealing in Mid Glamorgan
- Eaves beam and gutter repairs in Mid Glamorgan
- Slipped glass panel repairs in Mid Glamorgan
- uPVC roof lantern repairs in Mid Glamorgan
- Roof lantern respraying in Mid Glamorgan
Nearby areas
- Flat roof junction and flashing repairs in South Glamorgan
- Flat roof junction and flashing repairs in West Glamorgan
- Flat roof junction and flashing repairs in Gwent
- Flat roof junction and flashing repairs in Powys
- Flat roof junction and flashing repairs in Dyfed
More about flat roof junction and flashing repairs · All roof lantern repairs in Mid Glamorgan