Southampton at a glance
- Postcode districts
- SO14, SO15, SO16, SO17, SO18, SO19
- Population
- about 269,781 (GeoNames)
- Council area
- Southampton City Council
- Building approval
- Southampton City Council building control, or a registered building control approver
- Guide price region
- South East (+10% on West Midlands rates)
Why choose GRP fibreglass roofing in Southampton?
Landlords and small businesses in Southampton often favour GRP on roofs that contractors need to access for plant, aerials or gutter clearance. The surface resists scuffs better than a soft membrane, and small damage can usually be ground back and re-laminated without disturbing the rest of the roof.
In and around Southampton, flat roofs are typically found on newer estates where the first extension roofs are now being replaced, and on 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.
How much does a GRP fibreglass roof cost in Southampton?
Guide price in Southampton: £3,300–£5,900 for a 20 m² extension roof in GRP with a new deck and insulation, 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 |
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
- Moulded GRP trims, kerbs and upstands
- Warm-roof insulation and vapour control layer where the room below is heated
- New OSB3 or plywood deck, fixed at close centres
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 Southampton: questions
Do you cover Southampton?
Yes. Southampton is part of our Hampshire coverage, including postcode districts SO14, SO15, SO16, SO17, SO18, SO19. 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 Southampton?
Where the work needs approval it goes to Southampton City 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 Southampton?
£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.
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.
Does GRP smell when it is being laid?
Yes, the resin gives off a strong styrene smell while it cures. It usually fades within a day or so, and we advise keeping nearby windows closed while the team works.