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Flat roof systems

GRP fibreglass roofing in Hillingdon

Our GRP service in Hillingdon covers full replacement of tired felt and failed fibreglass roofs, as well as new roofs on extensions. Every job includes deck checks, careful joint reinforcement and a UV-stable topcoat, with a written workmanship guarantee on every re-roof and manufacturer guarantees registered where the system allows.

Finished grey GRP fibreglass flat roof with moulded trims on a single-storey extensionComputer-generated example image

Hillingdon at a glance

Postcode districts
UB8, UB10, UB11, UB7, UB4, HA4
Council area
London Borough of Hillingdon
Building approval
London Borough of Hillingdon building control, or a registered building control approver
Guide price region
London (+20% on West Midlands rates)

Why choose GRP fibreglass roofing in Hillingdon?

GRP is a good fit in Hillingdon 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.

Around Hillingdon, flat roofs are common on shops with flat-roofed stores below flats above and on kitchen extensions and roof terraces behind period houses. The Thames basin is one of the drier parts of Britain at roughly 730 mm of rain a year, but summer heat is the bigger test here: dark membranes on south-facing roofs swing a long way in temperature.

How much does a GRP fibreglass roof cost in Hillingdon?

Guide price in Hillingdon: £3,600–£6,450 for a 20 m² extension roof in GRP with a new deck and insulation, including VAT at London rates. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Extension (20 m²), GRP, new deck + insulation£3,600–£6,450
Dormer (8 m²), GRP, scaffold£1,700–£3,200
Single garage (18 m²), GRP fibreglass£2,150–£3,900
Single garage (18 m²), EPDM rubber£1,900–£3,350
Extension (20 m²), EPDM, new deck + insulation£3,350–£5,850

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?

  • Resin and glass-mat laminate with taped and reinforced joints
  • Moulded GRP trims, kerbs and upstands
  • Removal of the old covering and disposal of waste
  • 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 Hillingdon: questions

Do you cover Hillingdon?

Yes. Hillingdon is part of our London coverage, including postcode districts UB8, UB10, UB11, UB7, UB4, HA4. 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 Hillingdon?

Where the work needs approval it goes to London Borough of Hillingdon 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 Hillingdon?

£3,600–£6,450 for a 20 m² extension roof in GRP with a new deck and insulation, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

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.

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.

Other flat roof work in Hillingdon

GRP fibreglass roofing in Hillingdon: get a fixed price

Free survey and a written fixed quote for replacement and new roofs. No obligation.

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