- Price per m²
- £75–£140
- Typical life
- 20–40 years
- Manufacturer guarantees
- 20–25 year material warranties on specified systems
- Typical garage roof
- £1,800–£3,250
Warwickshire at a glance
- Largest towns
- Nuneaton, Rugby, Royal Leamington Spa, Warwick
- Postcode areas
- CV
- Building control
- Nuneaton and Bedworth Borough Council, Rugby Borough Council, Warwick District Council and 1 other council
- Neighbouring areas
- West Midlands · Leicestershire · Worcestershire · Northamptonshire
- Guide price region
- West Midlands (baseline rates)
How much does a GRP fibreglass roof cost in Warwickshire?
Guide prices including VAT at West Midlands rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), GRP, new deck + insulation | £3,000–£5,400 |
| Dormer (8 m²), GRP, scaffold | £1,400–£2,650 |
| Single garage (18 m²), GRP fibreglass | £1,800–£3,250 |
| Single garage (18 m²), EPDM rubber | £1,600–£2,800 |
| Extension (20 m²), EPDM, new deck + insulation | £2,800–£4,900 |
Which flat roofs are common in Warwickshire?
Flat roofs in Warwickshire sit on low-rise post-war blocks of flats, 1960s and 1970s link-detached houses with flat-roofed garages and porches and shops with flat-roofed rear stores below flats. England averages roughly 870 mm of rain a year and the West Midlands sits close to that, so falls and outlets are the difference between a roof that drains and one that ponds. 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 Warwickshire the application goes to Nuneaton and Bedworth Borough Council, Rugby Borough Council, Warwick District Council and 1 other council. More on the rules.
Will a new GRP roof need extra insulation to meet building regulations?
If the roof is over a heated room and you are replacing more than half of it, usually yes. In England, Wales and Northern Ireland that counts as renovating a thermal element, and in Scotland the council's building standards service will say whether a building warrant applies.
GRP pairs well with a warm roof because the new deck boards it needs can sit on top of the insulation. The result is thicker, so we check at survey that there is room under door cills and wall flashings, and that the upstands can finish around 150 mm above the new surface. Where approval is needed we arrange it with building control or building standards.
Unheated, detached garages normally sit outside the thermal rules. See the building regulations page for each nation, or the warm vs cold roof guide for why we avoid cold roofs where we can.
Why do GRP roofs crack, and can weather affect the installation?
GRP usually cracks where the structure moves and the laminate cannot, typically along board joints, at the junction with trims, or where a roof meets a wall. Weather during laying is the other big factor, because resin cures by chemical reaction and that reaction is sensitive to temperature and moisture.
How we reduce the risk of cracking:
- boards fixed at close centres so the deck does not flex;
- joints taped and reinforced with an extra strip of mat;
- wall junctions finished with a separate trim or flashing, not laminated hard into the masonry;
- roofs over a certain size divided with movement details where the system calls for them.
And how weather is managed:
- no laminating in rain, on a damp deck, or when dew or frost is likely before the resin sets;
- catalyst levels adjusted for the temperature, so resin neither stays tacky on a cold day nor kicks too fast in summer heat;
- the roof sheeted over if a shower threatens a fresh laminate.
That is why a GRP date can move at short notice. A day's delay costs far less than a laminate that never cures properly.
Which towns in Warwickshire do we cover?
GRP fibreglass roofing in Warwickshire: questions
Which towns in Warwickshire do you cover?
All of Warwickshire. 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 Warwickshire?
£3,000–£5,400 for a 20 m² extension roof in GRP with a new deck and insulation, at West Midlands 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 Warwickshire?
It depends on where the roof is: in Warwickshire that's Nuneaton and Bedworth Borough Council, Rugby Borough Council, Warwick District Council and 1 other council. 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. We confirm which applies at the survey.
Can GRP be laid over an existing felt roof?
Generally no. GRP needs a clean, dry, rigid timber deck, so the old felt is usually stripped and the boards replaced before laminating.
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 you walk on a GRP roof?
Yes, a correctly laid GRP roof takes occasional foot traffic, such as cleaning windows or maintaining plant. For a regular walkway or terrace, an anti-slip topcoat and a suitable specification are needed.
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