St Austell at a glance
- Postcode districts
- PL25
- Population
- about 24,360 (GeoNames)
- Council area
- Cornwall Council
- Building approval
- Cornwall Council building control, or a registered building control approver
- Guide price region
- South West (+3% on West Midlands rates)
Why choose GRP fibreglass roofing in St Austell?
GRP is a good fit in St Austell for roofs with awkward shapes, short runs of upstand and lots of corners, because every detail is laminated in place rather than cut and glued. Where a sheet membrane would need many joins, fibreglass forms one continuous skin across the whole roof.
In and around St Austell, flat roofs are typically found on 1930s semis with flat-roofed garages and kitchen extensions, and on 1960s and 1970s link-detached houses with flat-roofed garages and porches. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage.
How much does a GRP fibreglass roof cost in St Austell?
For St Austell we use South West rates: £3,100–£5,550 is the guide for a 20 m² extension roof in GRP with a new deck and insulation, VAT included. 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 | £3,100–£5,550 |
| Dormer (8 m²), GRP, scaffold | £1,450–£2,750 |
| Single garage (18 m²), GRP fibreglass | £1,850–£3,350 |
| Single garage (18 m²), EPDM rubber | £1,650–£2,900 |
| Extension (20 m²), EPDM, new deck + insulation | £2,900–£5,050 |
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.
What's included?
- Coloured UV-stable topcoat, with anti-slip finish on request
- Removal of the old covering and disposal of waste
- Warm-roof insulation and vapour control layer where the room below is heated
- Resin and glass-mat laminate with taped and reinforced joints
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
GRP fibreglass roofing in St Austell: questions
Do you cover St Austell?
Yes. St Austell is part of our Cornwall coverage, including postcode districts PL25. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in St Austell?
Where the work needs approval it goes to Cornwall Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a GRP fibreglass roof cost in St Austell?
£3,100–£5,550 for a 20 m² extension roof in GRP with a new deck and insulation, at South West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
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.