- Price per m²
- £74–£137
- Typical life
- 20–40 years
- Manufacturer guarantees
- 20–25 year material warranties on specified systems
- Typical garage roof
- £1,750–£3,200
Lincolnshire at a glance
- Largest towns
- Lincoln, Grimsby, Scunthorpe, Boston
- Postcode areas
- DN, LN, NG, PE
- Building control
- City of Lincoln Council, North East Lincolnshire Council, North Lincolnshire Council and 6 other councils
- Neighbouring areas
- Nottinghamshire · East Riding of Yorkshire · South Yorkshire · Derbyshire
- Guide price region
- East Midlands (−2% on West Midlands rates)
How much does a GRP fibreglass roof cost in Lincolnshire?
Guide prices including VAT at East Midlands 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 | £2,950–£5,300 |
| Dormer (8 m²), GRP, scaffold | £1,350–£2,600 |
| Single garage (18 m²), GRP fibreglass | £1,750–£3,200 |
| Single garage (18 m²), EPDM rubber | £1,550–£2,750 |
| Extension (20 m²), EPDM, new deck + insulation | £2,750–£4,800 |
Which flat roofs are common in Lincolnshire?
Flat roofs in Lincolnshire sit on terraced streets with flat-roofed rear kitchens and bathrooms, bungalows with flat-roofed side extensions and dormers and low-rise post-war blocks of flats. The East Midlands is drier than the west of Britain, so most flat roofs here fail through age, UV and poor detailing at upstands rather than sheer rainfall. 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 Lincolnshire the application goes to City of Lincoln Council, North East Lincolnshire Council, North Lincolnshire Council and 6 other councils. 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.
Why do GRP roofs crack, and can weather affect the installation?
GRP usually cracks where the structure moves and the laminate cannot, typically along board joints, at the junction with trims, or where a roof meets a wall. Weather during laying is the other big factor, because resin cures by chemical reaction and that reaction is sensitive to temperature and moisture.
How we reduce the risk of cracking:
- boards fixed at close centres so the deck does not flex;
- joints taped and reinforced with an extra strip of mat;
- wall junctions finished with a separate trim or flashing, not laminated hard into the masonry;
- roofs over a certain size divided with movement details where the system calls for them.
And how weather is managed:
- no laminating in rain, on a damp deck, or when dew or frost is likely before the resin sets;
- catalyst levels adjusted for the temperature, so resin neither stays tacky on a cold day nor kicks too fast in summer heat;
- the roof sheeted over if a shower threatens a fresh laminate.
That is why a GRP date can move at short notice. A day's delay costs far less than a laminate that never cures properly.
Which towns in Lincolnshire do we cover?
GRP fibreglass roofing in Lincolnshire: questions
Which towns in Lincolnshire do you cover?
All of Lincolnshire. 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 Lincolnshire?
£2,950–£5,300 for a 20 m² extension roof in GRP with a new deck and insulation, at East Midlands 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 Lincolnshire?
It depends on where the roof is: in Lincolnshire that's City of Lincoln Council, North East Lincolnshire Council, North Lincolnshire Council and 6 other councils. 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.
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.
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.
Is GRP suitable for a dormer roof?
Yes, GRP is commonly used on dormers because the trims can be moulded neatly and the finish looks tidy from the ground. Scaffold is normally needed, which we include in the quote.
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