Fibreglass roofing: GRP flat roofs with no joins to fail
Fibreglass roofing across Bedfordshire, Hertfordshire, Buckinghamshire and North London: GRP flat roofs laminated as one jointless shell. Get a free, no obligation quote today, backed by a 20 year written guarantee.
All work is backed with a 20 year written guarantee
Over 25 years' experience, family business
Fully insured, risk assessment before every job
We will beat any written quote
Free GRP fibreglass roofing quote
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Three quick steps. We ring you back to arrange a free survey.
Free, no obligation20 year written guaranteeWe beat any written quote
GRP laminate in 450g or 600g chopped strand matting, one or two layers
Polyester laminating resin, catalysed and rolled out to remove air
Pigmented topcoat in grey, slate or black, with UV protection
New 18mm ply or OSB3 deck, screwed, with firring strips for the falls
GRP edge trims, drip details and formed upstands in the same laminate
Roof lights and kerbs laminated straight into the roof
Walkable finishes for balconies, terraces and access routes
Repairs to cracks, crazing and worn topcoat on existing GRP roofs
Fibreglass roofing: a GRP roof laminated on your deck
GRP means glass-reinforced plastic. We build it on site: chopped strand matting, 450g or 600g per square metre, laid into catalysed polyester resin on your deck and rolled out until the glass is saturated and the air is gone. A pigmented topcoat goes over it for UV protection and colour. The result is a single, rigid, jointless shell, bonded to the roof and carried up into the upstands, kerbs and trims.
That shell has no laps to open and no seams to peel, which is why GRP is our first suggestion for balconies, dormers, bays and any roof with lots of detail. Doyle Homes has over 25 years' experience across flat and pitched roofing, we are fully insured and all work is backed with a 20 year written guarantee.
How we lay a GRP roof
A stiff, dry deck
Fibreglass is rigid, so a deck that flexes will crack it. We lay 18mm exterior ply or OSB3, screwed to the joists with the boards tight, and add noggins where an edge is unsupported. Firring strips give the fall to the outlet. If the old deck is soft, wet or sagging, it is replaced before anything is laminated.
Trims first, then matting and resin
GRP edge trims and drip details are fixed first, so the laminate wraps cleanly over them. Resin is catalysed to suit the day's temperature, matting is laid into it and a roller consolidates every layer until no dry glass shows. A 450g layer covers many roofs, and we lay 600g or two layers where the roof takes foot traffic or spans a wide deck.
Topcoat and cure
The pigmented topcoat goes on once the laminate has gelled. Fibreglass goes down on a dry deck, in dry weather, and then cures to a hard, walkable surface. Rain on wet resin spoils the finish, so we lay when the roof is dry and the forecast is clear.
Details laminated in
Upstands, corners, kerbs and the junction with a roof light are formed in the same laminate as the main surface. There is no separate flashing to lift, which removes the most common leak point on a flat roof.
Where fibreglass roofing beats felt and rubber
A GRP surface is hard-wearing and walkable, so it suits balconies, terraces and roofs you step onto for maintenance. It handles awkward shapes, curves and penetrations better than a sheet material, because it is formed in place. Colours are consistent, the surface cleans down with a brush and water, and there is no flame, no bitumen smell and no hot work on site.
It is not the answer to everything. A very large, plain roof is quicker and cheaper in EPDM rubber. A small garage on a tight budget suits torch-on felt. We set the three side by side on our flat roofing page, and we tell you which fits your roof after the survey.
How a GRP roof fails and how we repair it
GRP roofs fail from the deck up. Movement in the boards shows as straight hairline cracks along the joints. Thin lamination or too little topcoat lets UV chalk the surface, until glass fibres show through. Trapped moisture raises blisters. A cracked edge trim lets water under the laminate at the perimeter.
We find the cause before we touch the roof: we check the boards for movement, probe for soft spots and look for the water's path in the ceiling below. Cracks and worn patches are ground back, re-laminated with matting and resin and re-coated, a repair that is nearly invisible once the topcoat is matched. A roof with a failed deck, or one cracked across its whole width, is stripped and relaid, and we put that quote beside the repair.
Fibreglass roofing for balconies, dormers and extensions
The jobs we lay GRP on most are balcony and terrace roofs, dormers, bay roofs, porches and rear extensions with roof lights. We have laid new grey fibreglass on a rear extension and a narrow side extension, and our photographs show the finish. For garage frames and extension joists, see garage and extension roofs.
Our flat roof reviews include a weathered dormer bungalow roof renewed, with ridge tiles and gutters, in a day and a half, and neighbours ordering the same after seeing a finished roof. Ask for a free, no obligation survey and we put the findings and price in writing.
GRP roof cost and guarantee
Price follows area, the number of details, the state of the deck and the thickness of laminate. Your written quote itemises materials and labour with no hidden costs, and we will beat any written quote you hold. Our flat roof cost guide shows the ranges, and we offer flexible payment options and financing plans to suit your budget.
All work is backed with a 20 year written guarantee. If you have cause for concern after we finish, call us and we make sure any issue is fully rectified.
GRP roofers near you
We work from our Dunstable office across Bedfordshire, Hertfordshire, Buckinghamshire and North London, with local pages for Luton, St Albans, Harrow and Hemel Hempstead. Customers rate us 4.91 from 62 reviews on TrustATrader, 4.7 from 23 on Google and 9.63 from 73 on Checkatrade. Ring 01582 807949 to book your survey.
Signs you need us
Hairline cracks running along the deck joints
Crazed, chalky or faded topcoat letting the glass fibres show
Blisters or soft patches where moisture sits under the laminate
Cracked or lifting edge trims and corners
Water ponding on the surface after rain
Leaks at roof lights, upstands or the wall junction
An old felt or lead balcony that keeps leaking
How it works
How it works, from first call to guarantee
Survey and deck check
We inspect the surface, the falls, the trims and the deck, check the boards for movement and moisture, and tell you whether your roof suits fibreglass and what the deck needs first.
Deck and trims
Old covering comes off, the deck is replaced or stiffened, falls are corrected and the GRP edge trims are fixed, so the laminate goes on a stable, dry base.
Lay, roll and topcoat
Resin and matting are laid wet and rolled out to remove air, then the pigmented topcoat is applied. Upstands, kerbs and corners are laminated in one continuous skin.
Cure, inspect and guarantee
We let the laminate cure, check every edge and junction, clear the site and issue your 20 year written guarantee.
Our own photos
Recent GRP fibreglass roofing work
Every photo is from a job we worked on. Tap any image to see it full size.
Word for word, each one linked to the platform it was left on.
TrustATrader review
Flat roof on our 60 year old dormer bungalow had become badly weathered and in danger of leaking. Also ridge tiles and gutters needed replacing. In Doyle Homes I couldn't have made a better choice. No time was lost and all work was completed in a day and a half. Hugh Oshea's project management, advice and communication was excellent, and his team of roofers were hard working, skilful, efficient and polite at all times. The final result far exceeded my expectations for a very fair price. Highly recommended.
Yesterday I had my flat roof replaced by Doyle Homes and I couldn't be more impressed with their work. From their professionalism and attention to detail were exemplary. The team arrived promptly, worked efficiently, and maintained a clean work environment throughout the project. Communication was excellent and I needed some additional work doing which they dealt with. The end result exceeded my expectations, with a beautifully installed roof that provides both aesthetic appeal and peace of mind. I highly recommend Doyle Homes for any roofing needs.
Would recommend this company to others. Our neighbours in the street have already placed an order for a flat roof as a result of our work. My daughter also has had this company for many years conducting works on their properties, and found them to be excellent.Our roof looks great and Robert and the team are great people to deal with.
All work is backed with a 20 year written guarantee
Every job, from a single slipped tile to a full re-roof, comes with a 20 year guarantee in writing. You get it with your paperwork when the job is signed off, and if anything we did lets you down inside those 20 years, you ring the same number and we come back and put it right.
Fibreglass roofing, also called GRP, is a roof covering built on site from glass matting laminated in resin and finished with a pigmented topcoat. It cures into one rigid, jointless, waterproof shell bonded to the deck.
How long does a fibreglass roof last?
A well-laid GRP roof on a sound deck is built to outlast the 20 year written guarantee we give on every job. The deck, the lamination and the topcoat thickness decide the result, and that is where we spend the time.
Is fibreglass better than EPDM or felt?
For balconies, walkways and detailed roofs, yes. For very large plain roofs, EPDM can be quicker and cheaper. For small garages on a tight budget, felt wins. We survey first and recommend the system that fits.
Can fibreglass be laid in winter?
Resin needs a dry deck and dry weather, so we lay GRP when the roof is dry and the forecast is clear, and we adjust the resin mix to the temperature. Other systems suit a wet spell better, and we tell you if yours is one of them.
Can you repair my existing fibreglass roof?
Yes. We grind back cracks and worn patches, re-laminate with matting and resin and re-coat with a matched topcoat. If the deck has failed or the cracking runs across the roof, we show you why a new roof is the better spend.
Can you walk on a GRP roof?
Yes. GRP is a hard-wearing, walkable surface, and we lay heavier 600g matting or two layers for balconies and terraces that take daily use.
Do you guarantee fibreglass roofing?
Yes. All work is backed with a 20 year written guarantee, and we are fully insured. You also get a free, no obligation quote and our promise to beat any written quote.
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