Flat RoofingContractors

Flat roof systems

Single-ply membrane roofing across Merthyr Tydfil

Looking after a commercial or residential building in Merthyr Tydfil? Single-ply is often the best fit for medium and large flat roofs. We handle strip-out, insulation, membrane and details, plus any building control or building standards approval needed, and every re-roof carries our written workmanship guarantee with the length set out in the quote.

Light grey single-ply membrane roof with welded seams, outlets and plant on a commercial buildingComputer-generated example image
Price per m²
£83–£133
Typical life
25–35+ years
Manufacturer guarantees
20–25 year guarantees on specified systems
Typical garage roof
£1,900–£3,050

Merthyr Tydfil at a glance

Largest towns
Merthyr Tydfil, Treharris
Postcode areas
CF
Building control
Merthyr Tydfil County Borough Council
Neighbouring areas
Rhondda Cynon Taf · Blaenau Gwent · Caerphilly · Torfaen
Guide price region
Wales (−8% on West Midlands rates)

How much does a single-ply roof cost in Merthyr Tydfil?

Guide prices including VAT at Wales rates. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Commercial roof (100 m²), single-ply + insulation£12,150–£20,050
Single garage (18 m²), single-ply£1,900–£3,050
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 Merthyr Tydfil?

Flat roofs in Merthyr Tydfil sit on bungalows with flat-roofed side extensions and dormers, low-rise post-war blocks of flats 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 Merthyr Tydfil the application goes to Merthyr Tydfil County Borough Council. More on the rules.

Should a single-ply roof be mechanically fixed or adhered, and how are the seams welded?

Most commercial single-ply roofs are mechanically fixed, while adhered systems suit decks that cannot take fixings or roofs where a smooth finish is wanted. The choice depends on the deck, the wind exposure of the site and the manufacturer's specification.

MethodHow it worksTypical use
Mechanically fixedFasteners and plates hold the membrane through the insulation into the deck, hidden under the lap of the next sheetMetal, timber and concrete decks on commercial roofs
AdheredMembrane bonded to the insulation or deck with adhesiveDomestic roofs, roofs where fixings are unsuitable
BallastedLoose-laid and held down by paving, gravel or a green roofInverted roofs, terraces, green roofs

Fixing patterns are worked out for the site, with more fasteners at corners and perimeters, where wind uplift is strongest.

Seams are welded by hot-air machines and hand tools that melt the overlapping edges so they fuse. Each seam is then probed along its length to find any gaps, and test welds are made at the start of the day to set the machine for the weather. On commercial jobs we also check that walkways protect the membrane around plant.

Is single-ply the right system for my roof?

Single-ply is usually the right system for medium and large flat roofs, such as shops, offices, units, surgeries, clubs and blocks, where speed of installation, light weight and long life matter. On a small domestic roof it can work well, though it is not always the most economical choice.

In its favour: lightweight; quick to lay over large areas; flame-free, as the seams are welded with hot air; long typical life; welded details at rooflights and plant; lighter-coloured membranes reflect more sunlight.

Against it: only one waterproof layer, so welding quality is critical; can be punctured by foot traffic or dropped tools without walkway protection; PVC needs separating from bitumen; repairs need compatible material and welding equipment.

For a small garage or extension, EPDM is often simpler. Where people walk regularly, GRP or a liquid system may be tougher. A multi-layer torch-on felt roof gives built-in redundancy, and on older buildings mastic asphalt may be the original material. Our commercial flat roofing page covers larger jobs.

Which towns in Merthyr Tydfil do we cover?

Single-ply membrane roofing in Merthyr Tydfil: questions

Which towns in Merthyr Tydfil do you cover?

All of Merthyr Tydfil. 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 single-ply roof cost in Merthyr Tydfil?

£12,150–£20,050 for a 100 m² commercial roof in single-ply with insulation, 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 Merthyr Tydfil?

All of Merthyr Tydfil, including the CF postcode areas. Send your full postcode and we'll confirm.

Is single-ply roofing noisy in the rain?

No more than other flat roofs. Noise depends far more on the deck and insulation than on the membrane, and an insulated warm roof dampens rain noise well.

Can single-ply be used on a house?

Yes. It can be used on garages, extensions and dormers, usually adhered rather than mechanically fixed. On small domestic roofs, though, EPDM or GRP is often more economical.

Does single-ply work with solar panels or a green roof?

Usually, yes. Many systems can be specified for sedum or ballasted green roofs, and solar mounts can be welded or ballasted, though the structure and wind loads must be checked first.

Everything about single-ply membrane roofing → · All flat roofing in Merthyr Tydfil →

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