- Price per m²
- £83–£154
- Typical life
- 20–40 years
- Manufacturer guarantees
- 20–25 year material warranties on specified systems
- Typical garage roof
- £1,950–£3,600
Oxfordshire at a glance
- Largest towns
- Oxford, Banbury, Abingdon, Bicester
- Postcode areas
- OX
- Building control
- Oxford City Council, Cherwell District Council, Vale of White Horse District Council and 2 other councils
- Neighbouring areas
- Buckinghamshire · Berkshire · Bedfordshire · Warwickshire
- Guide price region
- South East (+10% on West Midlands rates)
How much does a GRP fibreglass roof cost in Oxfordshire?
Guide prices including VAT at South East 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 | £3,300–£5,900 |
| Dormer (8 m²), GRP, scaffold | £1,550–£2,900 |
| Single garage (18 m²), GRP fibreglass | £1,950–£3,600 |
| Single garage (18 m²), EPDM rubber | £1,750–£3,100 |
| Extension (20 m²), EPDM, new deck + insulation | £3,100–£5,350 |
Which flat roofs are common in Oxfordshire?
Flat roofs in Oxfordshire sit on 1930s semis with flat-roofed garages and kitchen extensions, shops with flat-roofed rear stores below flats and terraced streets with flat-roofed rear kitchens and bathrooms. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain. 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 Oxfordshire the application goes to Oxford City Council, Cherwell District Council, Vale of White Horse District Council and 2 other councils. 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.
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.
Which towns in Oxfordshire do we cover?
GRP fibreglass roofing in Oxfordshire: questions
Which towns in Oxfordshire do you cover?
All of Oxfordshire. 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 Oxfordshire?
£3,300–£5,900 for a 20 m² extension roof in GRP with a new deck and insulation, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in Oxfordshire?
All of Oxfordshire, including the OX 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.
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.
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