- Guide price
- £110–£320
- Repair price
- Confirmed once the leak or damage is found
- Condition survey report
- £140–£280
- Coverage
- England, Wales, Scotland, NI
Caerphilly at a glance
- Largest towns
- Caerphilly, Risca, Gelligaer, Blackwood
- Postcode areas
- CF, NP
- Building control
- Caerphilly County Borough Council
- Neighbouring areas
- Torfaen · Merthyr Tydfil · Blaenau Gwent · Newport
- Guide price region
- Wales (−8% on West Midlands rates)
How much does a new roof edge or outlet cost in Caerphilly?
Guide prices including VAT at Wales rates. We confirm the price once we've traced the leak or seen the damage.
| Job | Guide price inc VAT |
|---|---|
| Outlet or drainage repair | £110–£320 |
| Localised patch repair | £140–£460 |
| Upstand or flashing repair | £230–£600 |
| Emergency temporary weatherproofing visit | £170–£410 |
| Condition survey and leak investigation | £140–£280 |
Which flat roofs are common in Caerphilly?
Flat roofs in Caerphilly sit on 1960s and 1970s link-detached houses with flat-roofed garages and porches, newer estates where the first extension roofs are now being replaced and shops with flat-roofed rear stores below flats. Wales averages roughly 1,460 mm of rain a year, among the wettest in Britain, so we design for steady run-off: proper falls, clear outlets and upstands well above the finished roof. Approximate 1991–2020 regional averages based on Met Office data.
Building regulations in Wales
Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. Renovated roofs are upgraded to around 0.16 W/m²K where feasible, and new extension roofs are built to 0.13 W/m²K under the Welsh Approved Document L. In Caerphilly the application goes to Caerphilly County Borough Council. More on the rules.
Do flat roofs need overflows?
Roofs that drain to internal outlets or behind parapets should normally have an overflow, so that if an outlet blocks, water spills somewhere visible instead of rising over the upstands and into the building.
An overflow is usually a spout or weir set through the parapet or kerb at a level below the top of the upstands. When water runs from it, that is a sign the main outlet is blocked or overloaded. On a simple roof that drains over a drip trim into an external gutter, the open edge itself does the same job.
We look at where the water goes in heavy rain, how many outlets the roof has for its size, and whether the outlets, hoppers and downpipes are clear and properly connected. Leaf guards on outlets help on roofs near trees, as long as they are cleared regularly.
Should I fix the edges and drainage or replace the whole roof?
Fix the edges and drainage on their own if the covering is in good condition and the deck is sound. If the covering is near the end of its life or the falls need correcting across the whole roof, it is usually better value to do everything together as part of a replacement.
Trims and outlets are bonded into the waterproofing, so replacing them means cutting into the covering around the edge. On a roof with plenty of life left, that is a worthwhile repair. On an old, brittle covering, the new detail can end up stronger than the roof around it, and correcting falls means taking the covering off anyway. Our repair or replace guide sets out how to decide.
Which towns in Caerphilly do we cover?
Edge trims, outlets and drainage in Caerphilly: questions
Which towns in Caerphilly do you cover?
All of Caerphilly. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a new roof edge or outlet cost in Caerphilly?
£110–£320 for an outlet or drainage repair, at Wales guide rates including VAT. We confirm the price once we've traced the leak or seen the damage.
Which council handles building control for a flat roof in Caerphilly?
It depends on where the roof is: in Caerphilly that's Caerphilly County Borough Council. Welsh guidance is that most re-roofing needs building control approval, so it's worth checking whenever more than a quarter of a roof is replaced or repaired. We confirm which applies at the survey.
Can a flat roof be re-laid with better falls?
Yes, as part of a replacement. Falls are corrected with tapered firring pieces under a new deck or with tapered insulation in a warm roof build-up.
What's the difference between a drip trim and an edge trim?
An edge trim finishes the edge of the roof and holds the waterproofing down. A drip trim has a profile that throws water clear into the gutter. On many roofs a single trim does both jobs.
How often should flat roof outlets be cleared?
At least once a year, ideally in autumn after the leaves fall, and more often for roofs under trees. A quick check after heavy storms is also worthwhile.
Everything about edge trims, outlets and drainage → · All flat roofing in Caerphilly →