Flat RoofingContractors

Flat roof systems

GRP fibreglass roofing in Borehamwood

Thinking about a GRP roof for a dormer or extension in Borehamwood? The finish is rigid and tidy, with trims moulded into the roof rather than glued on. It does need a dry day and a new deck, so we survey first, explain what is involved and give you a fixed written quote with no obligation.

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

Borehamwood at a glance

Postcode districts
WD6
Population
about 36,322 (GeoNames)
Council area
Hertsmere Borough Council
Building approval
Hertsmere Borough Council building control, or a registered building control approver
Nearest main town
Watford, about 5 miles
Guide price region
East of England (+5% on West Midlands rates)

Why choose GRP fibreglass roofing in Borehamwood?

Some Borehamwood homeowners pick GRP for appearance alone. The topcoat comes in several colours, the trims are moulded to match, and the finished roof looks tidy from upstairs windows. With good laying conditions and a sound deck, a GRP roof typically lasts 20 years or more.

In a town like Borehamwood, flat roofs are commonly found on 1930s semis with flat-roofed garages and kitchen extensions or terraced streets with flat-roofed rear kitchens and bathrooms. The East of England is the driest part of Britain, with parts of the Anglian region around 630 mm a year, so summer heat and UV, not rainfall, do most of the ageing on a felt roof.

How much does a GRP fibreglass roof cost in Borehamwood?

At East of England guide rates, a 20 m² extension roof in GRP with a new deck and insulation comes to £3,150–£5,650 including VAT. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Extension (20 m²), GRP, new deck + insulation£3,150–£5,650
Dormer (8 m²), GRP, scaffold£1,450–£2,800
Single garage (18 m²), GRP fibreglass£1,850–£3,400
Single garage (18 m²), EPDM rubber£1,700–£2,950
Extension (20 m²), EPDM, new deck + insulation£2,950–£5,150

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?

  • Moulded GRP trims, kerbs and upstands
  • Coloured UV-stable topcoat, with anti-slip finish on request
  • New OSB3 or plywood deck, fixed at close centres
  • Warm-roof insulation and vapour control layer where the room below is heated

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 Borehamwood: questions

Do you cover Borehamwood?

Yes. Borehamwood is part of our Hertfordshire coverage, including postcode districts WD6. 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 Borehamwood?

Where the work needs approval it goes to Hertsmere Borough 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 Borehamwood?

£3,150–£5,650 for a 20 m² extension roof in GRP with a new deck and insulation, at East of England guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

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.

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.

Other flat roof work in Borehamwood

GRP fibreglass roofing in Borehamwood: get a fixed price

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

Call usGet a guide price