- Guide price
- £140–£460
- 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 flat roof repair 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 |
|---|---|
| Localised patch repair | £140–£460 |
| Upstand or flashing repair | £230–£600 |
| Outlet or drainage repair | £110–£320 |
| 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, shops with flat-roofed rear stores below flats and lock-up garage blocks on estates. 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.
Which repair materials work with my type of flat roof?
The repair has to use the same system as the roof, because many flat roof materials don't bond to each other and some damage each other.
- Torch-on felt: repaired with compatible bitumen membrane, cut back to sound felt and lapped well beyond the defect. Torching near timber, insulation or fascias needs care, and some details are better done with cold-applied methods.
- EPDM rubber: repaired with EPDM patches and the manufacturer's primer and seam tape. Bitumen products and many general-purpose sealants won't bond to EPDM and shouldn't be used on it.
- GRP fibreglass: the area is ground back, then new resin and glass matting are laid and finished with topcoat to match.
- Liquid-applied and single-ply: repaired with the same manufacturer's products wherever possible, as mixing systems can affect a material guarantee.
- Mastic asphalt: cracks and blisters are cut out and made good with new asphalt by an operative who works with it.
A tin of roof sealant or bitumen paint may stop a drip for a while, but on the wrong membrane it makes a proper repair harder later.
Should I repair or replace my flat roof?
Repair it if the defect is isolated and the rest of the roof is sound, dry and still well within its working life. Replace it if leaks keep coming back, cracking or blistering is widespread, the insulation is wet or the deck feels soft underfoot.
A useful test is to ask whether a repair would still look sensible if a second leak appeared somewhere else a few months later. On a roof near the end of its life, patching one split tends to move the problem rather than solve it, and repeated call-outs soon add up to a large share of the cost of a new roof. On a roof that is a few years old with one storm-damaged lap, a repair is the right answer and we will say so.
Our repair or replace guide sets out the signs in more detail, and the lifespan guide gives typical service lives for each system.
Which towns in Caerphilly do we cover?
Flat roof repairs 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 flat roof repair cost in Caerphilly?
£140–£460 for a localised patch 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 you repair the roof if the ceiling is already damaged?
Yes. The roof is fixed first so the ceiling can dry out, and then a plasterer or decorator can make it good. Any wet insulation within the roof should be checked, as it may need replacing.
How long does a flat roof repair take?
Most small repairs take a few hours on site once the roof is dry. Larger upstand or outlet repairs can take a day or more, and setting up scaffold or access equipment adds time.
Will a repair affect my roof's guarantee?
It can. If the roof is still under a manufacturer's material guarantee, the repair should normally use that manufacturer's products and methods, so share any guarantee paperwork with us before work starts.
Everything about flat roof repairs → · All flat roofing in Caerphilly →