- Guide price
- £2,600–£4,500
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
Rhondda Cynon Taf at a glance
- Largest towns
- Rhondda, Tonypandy, Pontypridd, Aberdare
- Postcode areas
- CF
- Building control
- Rhondda Cynon Taf County Borough Council
- Neighbouring areas
- Merthyr Tydfil · Caerphilly · Bridgend · Blaenau Gwent
- Guide price region
- Wales (−8% on West Midlands rates)
How much does a flat roof replacement cost in Rhondda Cynon Taf?
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 |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,600–£4,500 |
| Single garage (18 m²), torch-on felt | £1,400–£2,400 |
| Extension (20 m²), GRP, new deck + insulation | £2,750–£4,950 |
| Single garage (18 m²), EPDM rubber | £1,450–£2,600 |
Which flat roofs are common in Rhondda Cynon Taf?
Flat roofs in Rhondda Cynon Taf sit on newer estates where the first extension roofs are now being replaced, terraced streets with flat-roofed rear kitchens and bathrooms and 1960s and 1970s link-detached houses with flat-roofed garages and porches. 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 Rhondda Cynon Taf the application goes to Rhondda Cynon Taf County Borough Council. More on the rules.
Which system should I replace my flat roof with?
The right system depends on the roof's size, shape, use and number of details, so no single material suits every roof. These are the usual starting points:
- EPDM rubber suits simple, rectangular roofs, where one sheet can often cover the area with few or no joins.
- GRP fibreglass suits roofs with many corners, rooflights or edges, and gives a rigid surface for occasional maintenance traffic.
- Torch-on felt is a layered, hard-wearing system that keeps the cost down on larger or plain roofs.
- Liquid-applied systems handle awkward details and can overlay a sound existing surface.
- Single-ply and mastic asphalt are more usual on commercial roofs, blocks and terraces.
We recommend a system at survey and explain why. Our EPDM vs GRP vs felt guide sets out the trade-offs if you want to compare first.
Do I need building regulations approval to replace a flat roof?
Often, yes. Replacing the covering of a flat roof over a heated room is usually treated as renovating a thermal element, which brings insulation requirements and, in most cases, approval.
In England, if more than half of that roof is renovated, the whole roof should be upgraded towards a U-value of 0.16 W/m²K for homes (0.18 for non-domestic buildings) where that is technically, functionally and economically feasible, judged against a simple payback of 15 years. Approval comes from building control or self-certification through a registered competent person scheme. Structural changes, or a covering that adds 15% or more to the roof's weight, also need approval.
The other nations differ: most re-roofing in Wales needs approval, Scotland works through building standards and the building warrant, and in Northern Ireland you contact the district council's building control first. An unheated detached garage is not normally a thermal element. Planning permission is not usually needed if the roof looks much the same afterwards, though listed buildings and conservation areas are different. We handle approvals where needed; see building regulations.
Which towns in Rhondda Cynon Taf do we cover?
Flat roof replacement in Rhondda Cynon Taf: questions
Which towns in Rhondda Cynon Taf do you cover?
All of Rhondda Cynon Taf. 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 replacement cost in Rhondda Cynon Taf?
£2,600–£4,500 for a 20 m² extension roof in EPDM with a new deck and insulation, at Wales guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in Rhondda Cynon Taf?
It depends on where the roof is: in Rhondda Cynon Taf that's Rhondda Cynon Taf 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.
Is VAT charged on a flat roof replacement?
Yes, roof replacement is standard-rated at 20%, and an insulated replacement is treated as a single supply. Our guide prices already include VAT.
What time of year is best for a flat roof replacement?
Late spring to early autumn gives the most reliable dry spells, but a roof can be replaced in any season when the forecast allows. Adhesives and resins have minimum application temperatures, so winter work is planned around mild, dry days.
Do I need to be at home while the roof is replaced?
Not for most of the job, as long as the team can reach the roof and there is room for a skip. We ask you to be there at the start to agree the plan and at the end to look over the finished roof.
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