- 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
Isle of Wight at a glance
How much does a GRP fibreglass roof cost in Isle of Wight?
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 Isle of Wight?
Flat roofs in Isle of Wight sit on shops with flat-roofed rear stores below flats, 1930s semis with flat-roofed garages and kitchen extensions and 1960s and 1970s link-detached houses with flat-roofed garages and porches. 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 Isle of Wight the application goes to Isle of Wight 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 Isle of Wight do we cover?
GRP fibreglass roofing in Isle of Wight: questions
Which towns in Isle of Wight do you cover?
All of Isle of Wight. 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 Isle of Wight?
£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 council handles building control for a flat roof in Isle of Wight?
It depends on where the roof is: in Isle of Wight that's Isle of Wight 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.
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.
How long before a new GRP roof is fully cured?
The topcoat is usually touch-dry within hours in reasonable weather, but full cure takes longer in cold conditions. We advise keeping off the roof until the team confirms it is ready.
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