- Price per m²
- £83–£129
- Typical life
- 10–25+ years by product
- Manufacturer guarantees
- 10, 15 or 20-year guarantees by named system
- Typical garage roof
- £1,900–£3,000
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 liquid-applied roof cost in Caerphilly?
Guide prices including VAT at Wales rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Single garage (18 m²), liquid-applied | £1,900–£3,000 |
| Balcony (12 m²), liquid-applied, scaffold | £1,750–£3,000 |
| Single garage (18 m²), EPDM rubber | £1,450–£2,600 |
| Extension (20 m²), EPDM, new deck + insulation | £2,600–£4,500 |
Which flat roofs are common in Caerphilly?
Flat roofs in Caerphilly sit on 1930s semis with flat-roofed garages and kitchen extensions, newer estates where the first extension roofs are now being replaced and terraced streets with flat-roofed rear kitchens and bathrooms. 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 building regulations apply if a liquid coating goes over my roof?
They can. In England, Wales and Northern Ireland, re-covering more than half of a roof over a heated room is usually renovation of a thermal element, even when the new membrane goes over the old, so the roof should be insulated towards the renovation standard where feasible; for a Scottish property, the local building standards team will confirm whether a warrant is required.
A minor coating repair to a small area is different from re-covering the whole roof. Where insulation is needed, an overlay is not always practical, because the insulation has to go under a new waterproof layer. In that case we may recommend stripping to the deck, fitting a warm roof and applying the liquid system on top. Where approval applies, we deal with the paperwork; details are on the building regulations page.
Can a liquid roof go over my existing roof, and what preparation is needed?
Yes, if the existing roof is dry, firmly bonded and sitting on a sound deck. A liquid membrane is only as good as what lies beneath it, so we test the old roof before agreeing to overlay it.
At survey we check for:
- Trapped moisture: soft spots, blisters or wet insulation mean the roof should be stripped, because water sealed in will cause new blisters and decay.
- Deck condition: any sponginess or deflection needs repair first.
- Adhesion: on felt and asphalt, loose areas are cut out and patched, and the existing surface must take the primer properly.
- Falls and ponding: a coating follows the roof as it is. If water ponds now, it will pond on the new surface too unless the falls are corrected.
Preparation then follows: loose chippings removed, the surface cleaned and left to dry, blisters cut back and repaired, cracks filled, and the right primer applied. On older felt, mineral surfaces may need extra cleaning to give a good bond. Where the tests fail, we say so plainly and quote for a strip and re-roof. Read more on ponding water.
Which towns in Caerphilly do we cover?
Liquid-applied roofing 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 liquid-applied roof cost in Caerphilly?
£1,900–£3,000 for a typical 18 m² garage roof in a liquid-applied system, at Wales guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in Caerphilly?
All of Caerphilly, including the CF, NP postcode areas. Send your full postcode and we'll confirm.
Does a liquid roof smell when it is applied?
Some systems, particularly PMMA, have a strong odour during application, while many polyurethane and water-based products are milder. We tell you what to expect and plan around windows and vents.
Can liquid roofing stop a leak on a flat roof?
It can, if the leak is at a detail or the membrane is worn but the roof beneath is sound. If water has soaked the insulation or deck, coating over it will not cure the problem.
Is liquid roofing good for balconies?
Often, yes. It forms neatly around railings, door thresholds and drains, and some systems take foot traffic. A new balcony or roof terrace generally needs planning permission, so check before converting a roof.
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