07460 07229724/7 Available info@stormguardroofing.ukWitney · Oxfordshire · Cotswolds Services Service Areas Our WorkReviewsAboutContactGet a Free Quote - Roofers in Witney - Roofing Services - GRP fibreglassRoofing services # Seamless GRP Fibreglass RoofingIn Witney And OxfordshireGuaranteed For 20 Years A GRP roof cures into one continuous laminate with no joints and no seams to fail, tough enough to walk on and finished with rigid trims instead of sealant. Installed by a Restec approved installer and guaranteed for 20 years. Get my free fixed-price quote07460 072297 Restec GRP approved installer · 9.83/10 from 159 Checkatrade reviews ## Recent seamless grp fibreglass roofing work - 20 years Workmanship guarantee on GRP roofs - Restec GRP approved installer - 100+ Five-star Checkatrade reviews - £5m Public liability insurance - Free Quotes and inspections ## What GRP fibreglass roofing is GRP stands for glass reinforced plastic. Chopped strand glass matting is laid over a prepared deck and saturated with catalysed resin, then finished with a pigmented topcoat. It cures into a single rigid laminate that is bonded to the deck across its whole area, with no laps, welds or joints anywhere in the field of the roof. Because the trims are also GRP and are laminated into the roof rather than sealed to it, the edges become part of the same continuous surface. That removes the mechanical joints where most flat roofs eventually let go. The finished surface is hard. It takes foot traffic, it can be finished with an anti-slip aggregate for balconies and walkways, and it does not soften in summer heat the way bitumen can. That combination makes it the system we recommend for balconies, terraces, dormer tops and any roof that will be walked on. We install GRP as a Restec approved installer, on a build-up that includes the deck, insulation and vapour control appropriate to a warm or cold deck, and we guarantee our workmanship for 20 years. ### Who this is for, and when it is needed - Balconies, terraces and walkways Surfaces that get regular foot traffic and need a hard, non-slip finish rather than a soft membrane. - Dormer tops and small complex roofs Small areas where a seamless laminate and moulded trims outperform a covering held together at the edges. - New extensions being built now GRP is laid on a new plywood deck as part of the build, so the roof is finished and watertight in one visit. - Roofs where appearance matters A pigmented topcoat gives an even, deliberate finish that suits a roof visible from a window above. - Flat roofs with a history of joint failures If every leak has started at a lap, a trim or an upstand, a seamless system removes the failure point entirely. ## Why joints and trims are where flat roofs fail Most flat roof failures are not holes in the middle of the roof. They are movement, weathering and workmanship at the joints. ### What it leads to - A failed lap or trim lets water under the covering, where it spreads across the deck before it shows on any ceiling. - Once a plywood or chipboard deck takes on water it swells, loses strength and has to be replaced. - Soaked insulation stops insulating, so the room below is colder and more expensive to heat. - A soft, ageing surface on a balcony breaks down under foot traffic and furniture far faster than it does on a roof nobody walks on. - Water reaching joists rots timber out of sight and turns a covering job into a structural one. - Leaks at a balcony threshold or dormer junction run straight into the room, not into a loft where they can be spotted early. ### Common mistakes - Laying GRP over an unsuitable deck. It must go onto correctly specified and fixed board, not straight over old boards or an existing covering. - Skipping the trims and sealing the edge instead, which reintroduces the joint the system exists to avoid. - Rushing installation in cold or damp conditions, when resin cure is temperature and moisture dependent. - Ignoring falls, so a hard, well-installed roof ponds permanently. - Using GRP on a large area with significant thermal movement and no consideration of expansion detailing. GRP is unforgiving of poor preparation and very durable when it is done properly, which is exactly why we install it as an approved installer to a specified system. How we work ## Our process, start to finish - Step 1 ### Free inspection We assess the existing roof, its deck, its falls and its upstands, and confirm whether GRP is the right system for it. - Step 2 ### Diagnosis and fixed-price quote You receive photographs, an explanation, and a written quote stating the deck, build-up, trims and finish. - Step 3 ### Strip and deck preparation Old covering removed, correctly specified decking laid or repaired, falls corrected, insulation and vapour control installed to suit the build-up. - Step 4 ### Laminate and topcoat GRP trims fitted, matting laid and fully saturated with catalysed resin, upstands and detail laminated in, and the pigmented topcoat applied over the cured laminate. - Step 5 ### Verification and handover Cure and coverage checked, drainage proved, site cleared, and a before-and-after photographic report issued with your 20-year workmanship guarantee. What you get ## The difference it makes - ### 20-year workmanship guarantee The longest term we offer on a flat roof, matching our new pitched roof guarantee. - ### No joints in the field of the roof One continuous laminate removes the laps and seams that most flat roofs fail at. - ### Walk on it A hard surface suited to balconies, terraces and access routes, with an anti-slip finish where needed. - ### Approved installer Installed as a Restec GRP approved installer, to the system rather than to a shortcut. - ### Clean, even finish A pigmented topcoat and moulded trims give a deliberate appearance on roofs that are overlooked. - ### Photographic evidence Before-and-after reports covering the deck, the laminate and the finished roof. ## Materials, methods and applications ### Resin, matting and topcoat The laminate is built from chopped strand matting saturated with catalysed polyester resin. The matting has to be fully wetted out and consolidated so no dry glass is left in the laminate, because dry glass wicks water. The topcoat that follows is pigmented and provides the UV protection and the finished colour; the laminate below it is the waterproofing. Catalyst ratio is adjusted to conditions. Too little and the resin does not cure properly; too much and it goes off before it can be consolidated. It is a system with a working window, and that window is why weather and temperature affect scheduling. ### Decking requirements GRP needs a rigid, correctly specified deck, typically OSB3 or plywood to the right thickness, laid with staggered joints, correct fixing centres and the required expansion gaps. Laying over an old deck or an existing covering is not an option, because any movement or moisture below transfers straight into a rigid laminate. ### Trims, upstands and detailing Drip trims, raised edge trims, wall trims and simulated lead trims are bonded and laminated in so they become part of the roof. Upstands are laminated continuously up the wall to a proper height, and against masonry a lead cover flashing is chased in over the top. Internal and external corners are reinforced before the main laminate is laid. ### Trafficked surfaces and anti-slip Balconies, terraces and walkways can be finished with an aggregate broadcast into the topcoat, giving grip in the wet without adding a separate surface that has to be lifted for maintenance. Where furniture or planters will sit on the roof, we discuss protection so point loads do not wear the topcoat prematurely. ### Falls, outlets and rainwater Falls are built with firrings or tapered insulation before the deck is finished. GRP outlets are laminated in as part of the continuous surface, and where the roof discharges into a gutter or hopper we make sure that is sized and clear so the roof is not backing up in heavy rain. ### Where GRP is the right choice GRP is the system we recommend for trafficked surfaces, small to medium roofs with a lot of edge detail, and anywhere a hard, seamless finish is wanted. On very large areas with significant thermal movement, or on roofs where a flexible single-ply behaves better, EPDM or a felt system may be the better recommendation, and we will say so. ### Residential and commercial Domestic balconies, dormers, porches and extensions, and commercial entrance canopies, walkways and plant areas, are all standard GRP applications. Commercial work is phased so access routes stay usable. Questions ## Frequently asked How much does a GRP fibreglass roof cost?It depends on area, access, deck condition and how much trim and upstand detail is involved. The inspection and quote are free, and the quote is fixed price to the best of our ability. How long does a GRP roof last?GRP is a rigid, seamless laminate and it is one of the longest-lived flat roof systems we install. We guarantee our workmanship on it for 20 years. How long does installation take?Most domestic GRP roofs are a job of a few days, including deck preparation and cure time between stages. Weather affects resin cure, so we plan the laminate around the forecast rather than forcing it. Can I walk on a GRP roof?Yes. It is a hard-wearing surface and it is the system we recommend for balconies, terraces and walkways, with an anti-slip aggregate finish where the surface needs grip. Can GRP be laid over my existing flat roof?No. It needs a correctly specified new or repaired deck. Laying a rigid laminate over an old covering or a moving deck is how GRP roofs crack. Is GRP better than EPDM?For trafficked surfaces and roofs with a lot of edge detail, usually yes. For a large, simple rectangle with minimal detail, EPDM is often the better fit. Both carry our 20-year workmanship guarantee, so the choice is about the roof rather than the term. Will the colour fade?The topcoat carries the pigment and the UV protection, and colours weather over many years of exposure. The waterproofing is the laminate below it, so appearance and performance are separate things. Can a GRP roof be repaired?Yes. Damage can be ground back and re-laminated into the existing roof so the repair becomes part of the same continuous surface. Repair work carries a 5-year workmanship guarantee. Are you approved to install it?Yes: we are a Restec GRP approved installer, and also a Classic Bond EPDM approved installer, City & Guilds qualified and members of the Construction Award Alliance. Which areas do you cover?Witney, Stonesfield, Woodstock, Charlbury, Chipping Norton, Burford, Banbury and across Oxfordshire, Gloucestershire and Warwickshire including the Cotswolds. Related work ## Other services we handle - ### Flat Roofing In Witney Read more - ### EPDM Rubber Flat Roofing Read more - ### Torch-On Felt Flat Roofing Read more - ### Roof Repairs And Leak Tracing Read moreWe cover Witney, Stonesfield, Woodstock, Charlbury, Chipping Norton, Burford and the wider area. See all roofing services, recent work, or go back to the home page. ## Get a seamless GRP roof quoted Free inspection, a written specification from an approved installer, and a 20-year workmanship guarantee. 07460 0722979.83/10 from 159 Checkatrade reviews · £5,000,000 public liability · Free quotes and inspections Roofing contractor based in Witney, covering Oxfordshire, Gloucestershire and Warwickshire. Pitched and flat roofing, leadwork, and Grade II listed and conservation roofing across the Cotswolds. - 07460 072297 - 01993 898807 - info@stormguardroofing.uk - 24/7 On The Line - 11 Cockshoot Close, Stonesfield, Witney, Oxfordshire, OX29 8ED ### Services - Pitched roofing in Oxfordshire - Flat roofing in Oxfordshire - Felt flat roofs in Oxfordshire - GRP fibreglass in Oxfordshire - EPDM rubber in Oxfordshire - Leadwork in Oxfordshire - Listed & heritage in Oxfordshire - Fascias & guttering in Oxfordshire - Chimney work in Oxfordshire - Roof repairs in Oxfordshire - Emergency call-outs in Oxfordshire ### Areas Covered - Roofers in Witney - Roofers in Stonesfield - Roofers in Woodstock - Roofers in Charlbury - Roofers in Chipping Norton - Roofers in Burford - Roofers in Banbury - Roofers in Stow-on-the-Wold - Roofers in Moreton-in-Marsh - Roofers in Bourton-on-the-Water - Roofers in Chipping Campden - Roofers in Shipston-on-StourGet a Free Quote About Stormguard RoofingRoofing ReviewsRoofing ProjectsContact Our RoofersPrivacy PolicyCookie PolicyTerms & Conditions© 2026 Storm Guard Roofing Limited. 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