Flat RoofingContractors

Flat roof systems

GRP fibreglass roofing across South Yorkshire

GRP roofing in South Yorkshire suits dormers, extensions, garages and roofs that need occasional foot traffic. Rainfall and exposure vary across the area, so we plan laminating days carefully and sheet over fresh work if the forecast turns. The finished roof is a hard, jointless skin with moulded trims and a coloured topcoat.

Finished grey GRP fibreglass flat roof with moulded trims on a single-storey extensionComputer-generated example image
Price per m²
£71–£133
Typical life
20–40 years
Manufacturer guarantees
20–25 year material warranties on specified systems
Typical garage roof
£1,700–£3,100

South Yorkshire at a glance

Largest towns
Sheffield, Rotherham, Doncaster, Barnsley
Postcode areas
DN, S
Building control
Sheffield City Council, Rotherham Council, City of Doncaster Council and 1 other council
Neighbouring areas
West Yorkshire · Derbyshire · Nottinghamshire · Greater Manchester
Guide price region
Yorkshire and the Humber (−5% on West Midlands rates)

How much does a GRP fibreglass roof cost in South Yorkshire?

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

JobGuide price inc VAT
Extension (20 m²), GRP, new deck + insulation£2,850–£5,100
Dormer (8 m²), GRP, scaffold£1,350–£2,500
Single garage (18 m²), GRP fibreglass£1,700–£3,100
Single garage (18 m²), EPDM rubber£1,500–£2,650
Extension (20 m²), EPDM, new deck + insulation£2,650–£4,650

Which flat roofs are common in South Yorkshire?

Flat roofs in South Yorkshire sit on terraced streets with flat-roofed rear kitchens and bathrooms, 1960s and 1970s link-detached houses with flat-roofed garages and porches and newer estates where the first extension roofs are now being replaced. England averages roughly 870 mm of rain a year; the Pennine side of Yorkshire is wetter and windier than the east, so we specify for the site rather than the county. Approximate 1991–2020 regional averages based on Met Office data.

Building regulations in England

Replacing more than half of a roof over a heated room usually counts as renovating a thermal element, so it is insulated to current standards and notified to building control. Renovated roofs over heated rooms are insulated to around 0.16 W/m²K where that's feasible, and new extension roofs are built to 0.15 W/m²K. In South Yorkshire the application goes to Sheffield City Council, Rotherham Council, City of Doncaster Council and 1 other council. More on the rules.

How long does a GRP roof last, and is it guaranteed?

A properly laid GRP roof typically lasts 20 to 40 years. The range is wide because so much depends on the laminate being fully wetted out, the deck staying dry and stable, and the topcoat being renewed if it wears.

When GRP fails early, the cause is usually one of these:

  • resin laid in damp or cold conditions that never fully cured;
  • cracks at board joints or trims where movement was not allowed for;
  • a deck that was wet, soft or poorly fixed before laminating;
  • a thin or patchy topcoat that has weathered through.

On guarantees, manufacturer material guarantees are available on many specified GRP systems, and some need a registered build-up or an approved installer. Where registration is possible, we do it for you. Every re-roof also comes with our written workmanship guarantee, with the length set out in your quote, and you can ask about insurance-backed options. Read more in our guarantees guide.

Is GRP better than EPDM, felt or a liquid roof?

GRP is the better choice when you want a rigid, walkable finish, a neat look on a visible roof, or crisp moulded details on a complicated shape. It is not automatically better on a plain garage that nobody steps on.

Strengths: hard surface that takes occasional foot traffic; jointless finish with no laps; trims, kerbs and upstands moulded as part of the roof; choice of topcoat colours; small repairs can be laminated in.

Weaknesses: sensitive to weather while laying; rigid, so it can crack where the structure moves; usually needs a new deck; styrene smell during application; skill-dependent, so workmanship matters more than with sheet systems.

For a simple roof, EPDM rubber is often quicker to lay and more forgiving of movement. Torch-on felt is usually cheaper per square metre. A liquid-applied roof can go over a sound existing surface, larger commercial roofs tend to suit single-ply, and older buildings may already have mastic asphalt worth keeping. The EPDM vs GRP vs felt guide compares the three most common choices.

Which towns in South Yorkshire do we cover?

GRP fibreglass roofing in South Yorkshire: questions

Which towns in South Yorkshire do you cover?

All of South Yorkshire. 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 GRP fibreglass roof cost in South Yorkshire?

£2,850–£5,100 for a 20 m² extension roof in GRP with a new deck and insulation, at Yorkshire and the Humber guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

Which postcode areas do you cover in South Yorkshire?

All of South Yorkshire, including the DN, S postcode areas. Send your full postcode and we'll confirm.

What colours does a GRP roof come in?

Topcoats are typically available in greys, greens, black and some other shades. Lighter colours absorb less heat, and an anti-slip finish can be added where people will walk on the roof.

Can a cracked GRP roof be repaired?

Often, yes. The area is ground back, cleaned and re-laminated with fresh mat and topcoat. If cracks keep returning along joints, the deck or detailing usually needs attention rather than another patch.

Is GRP suitable for a dormer roof?

Yes, GRP is commonly used on dormers because the trims can be moulded neatly and the finish looks tidy from the ground. Scaffold is normally needed, which we include in the quote.

Everything about GRP fibreglass roofing → · All flat roofing in South Yorkshire →

Get a fixed price for your flat roof

Free survey and a written fixed quote for replacement and new roofs. No obligation.

Call usGet a guide price