GMG Roof Experts, the leading roofing company in London, offers top-tier roofing solutions tailored to your specific needs.
GMG Roof Experts install and repair GRP fibreglass flat roofs across the whole London Borough of Hillingdon. We strip the old covering back to the deck, renew any soft boarding, set the falls, and laminate a fully bonded glass fibre and resin roof with a seamless finish, no joints or laps for water to find. Garage roofs, extensions, dormer tops and cheeks, porches and balconies, from a new fibreglass roof on an outbuilding to a repair on a cracked laminate, all from our Hayes UB3 base across Uxbridge, Hayes, Ruislip, Ickenham, Northwood and every postcode in between.
The background
GRP stands for glass reinforced plastic, better known as fibreglass. It is built up on the roof itself from layers of glass fibre matting saturated in a catalysed resin, rolled out to remove air and left to cure into a rigid, fully bonded skin, then finished with a coloured, UV-stable topcoat. Unlike felt, which is laid in overlapping sheets, or a single-sheet membrane like EPDM, which still has upstand and trim joints, a GRP roof is laminated as one continuous surface with genuinely no laps or seams for water to find.
That makes it well suited to the flat and low-pitch roofs most common on Hillingdon homes: garage and outbuilding roofs, single-storey extensions, dormer tops and cheeks, porches, bay window roofs, and balconies or roof terraces that need to take regular foot traffic, which a rigid GRP surface handles better than a soft membrane.
Like any flat roof, a GRP roof is only as good as what is underneath it. We strip back to a sound deck, correct the falls with tapered firrings where water was ponding, and only then laminate the fibreglass, because a beautiful seamless finish over a rotten or badly sloped deck still leaks.
We are based in Hayes, we lay and repair GRP roofs across Hillingdon every week, and every job on this page is a real completed or in-progress GMG job, not a stock photograph.
What we do
From a new fibreglass roof on a garage to a repair on a cracked laminate, every job below is carried out by our own team, not subcontracted out, and every one starts with a close-up inspection and a written quote on request.
Stripping the old covering back to the deck, renewing soft boarding, correcting the falls and laminating a seamless GRP roof over the whole area.
The most common GRP job. A tired felt garage or extension roof stripped and re-covered in a fully bonded fibreglass laminate, tidy edge to edge.
GRP laminated in one continuous skin around rooflight kerbs, dormer cheeks and tight upstands, so the awkward junctions that fail in felt stay watertight.
A rigid, fully bonded GRP surface takes regular foot traffic better than a soft membrane, with an anti-slip topcoat available for areas people walk on.
Cracked laminate cut back and re-laminated, chalked or faded topcoat renewed, and failed upstands or trims re-bonded, without stripping a sound roof back to the deck.
GRP topcoat is available in a range of colours to suit the property, with a standard or anti-slip finish depending on whether the area will be walked on.
A GRP installation starts with the deck. We strip the old covering back to the boarding, cut out and renew anything soft or delaminated, and check the falls, adding tapered firrings where the roof has been ponding. GRP needs a rigid, dry, well-fixed deck to laminate onto, so this stage is not skipped.
With the deck sound, edge trims are fixed first so the laminate finishes flush and clean. The glass fibre matting is laid dry to check the fit, then saturated with catalysed resin and rolled out by hand to remove air, in a base coat and a top coat, formed into one continuous skin up every upstand and around every rooflight kerb. A pigmented, UV-stable topcoat finishes the surface, standard or anti-slip depending on how the roof will be used. The result is a single seamless membrane with genuinely no joints across the field.
How it works
The process is the same whether it is a new garage roof or a laminate repair, and it starts with a conversation, not a sales pitch.
Call 07949 999411 or use the contact form. Tell us what the roof covers, where it is leaking if it is, and roughly where the property is in Hillingdon.
We get up onto the roof, check the deck, the falls and the upstands, and send a written quote covering deck repairs, laminate, trims, outlet and access, with a repair option where one is realistic.
We set up tower or scaffold access as needed, strip the old covering, renew any soft deck and correct the falls before the fibreglass goes anywhere near it.
We laminate the GRP, fit the trims, outlet and flashings, test the roof, clear up and take the waste away, and give you a written summary with photographs of the finished roof.
The build
A GRP roof is built up in stages on site, not delivered as a pre-made sheet. Each stage matters, and it is the deck, the trims and the outlet, not just the laminate itself, that decide how long the roof lasts. We build all four properly and set them out in the written quote so you can see what you are paying for.
The finished laminate is one continuous, fully bonded skin, which is the main reason GRP has genuinely no field seams compared with a lapped covering like felt.
Soft or delaminated boards cut out and renewed in exterior-grade ply or OSB3, and tapered firrings added where the roof needs a fall.
Glass fibre matting saturated in catalysed resin and rolled out by hand to remove air, laminated in a base coat and top coat as one continuous skin.
Trims fixed first so the laminate finishes flush, and upstands and wall abutments formed from the same continuous skin, not a separate joint.
A pigmented, UV-stable topcoat finish, with bonded rainwater outlets and lead or GRP flashings where the roof meets a wall or a rooflight kerb.
Most flat roof failures start at a joint: a felt lap that has lifted, a membrane seam that was never fully bonded, a trim that has come loose at a corner. GRP does not have that weakness in the field of the roof, because the fibreglass is laminated in place as one continuous surface, not assembled from separate pieces.
That matters most on roofs with awkward shapes, tight upstands, rooflight kerbs, chimney abutments, where a lapped or sheet material struggles to form a clean, watertight corner without extra joints. A laminated GRP roof forms those corners from the same material as the flat field, with the reinforcement continuing round the angle rather than stopping at it.
Where a flat roof is going to be used as a balcony, a roof terrace or regular access to a plant or store area, the covering needs to take foot traffic, not just shed rainwater. A soft single-ply membrane can be walked on occasionally but wears faster under regular use. A laminated GRP surface is rigid and, with an anti-slip textured topcoat, is a practical choice for an area people actually stand and walk on.
We detail thresholds, upstands and any balustrade fixings into the laminate before the topcoat goes on, so the surface stays continuous and there is nowhere for water to get behind a fixing. Falls are set out to a proper outlet the same as any other flat roof, so the area sheds water even with regular use.
Completed work
Every image below is a real GMG Roof Experts photograph taken from the company's own site. Each one appears once, and the caption names the type of work where it could be confirmed from the source.
GRP fibreglass roofing is a defined part of what we do from our Hayes base, inside the borough, from a new garage roof to a laminate repair. That means we sort the deck and the falls first, and laminate a genuinely seamless roof with the trims, outlet and upstands detailed properly, not just rolled out over whatever was already there.
Our work runs from patching a crack on a sound roof to a full strip, deck renewal and new GRP roof. We are CITB certified, fully insured, and every job on this page is a real GMG photograph, and every job ends with a written summary and photographs of the finished roof.
Areas we cover
We cover the whole borough and the areas that border it. Each town below has its own location page with more local detail. If your postcode starts with UB3, UB4, UB7, UB8, UB9, UB10, HA4, HA5, HA6, SL0, SL9 or SL2, we can help.
Extension and outrigger flat roofs on Victorian and Edwardian terraces, with old felt failed at the wall abutment.
Roofers in Uxbridge →Our home patch. Garage and extension roofs re-covered in seamless GRP after split felt and ponding.
Roofers in Hayes →1930s semis with flat-roofed bay windows and rear additions, and detached garages needing a new fibreglass roof.
Roofers in Ruislip →Larger homes with dormer roofs, rooflight kerbs and extension roofs where GRP is laminated in one piece.
Roofers in Ickenham →Large detached properties with flat-roofed link extensions, garden rooms and balconies over living space.
Roofers in Northwood →Iver, Gerrards Cross and Stoke Poges in Buckinghamshire, where extension and outbuilding flat roofs need a lasting re-cover.
Ask about your area →GRP roofers near me
We cover every part of the borough for this work, not just the main towns, and our team is based in Hayes, so the person who inspects your flat roof is the person who scopes and prices the job.
GMG Roof Experts carries out new GRP flat roofs, garage and extension roofs, dormer and rooflight kerb detail, balcony and roof terrace roofs, GRP repairs and re-topcoating across Uxbridge, Hayes, Ruislip, Eastcote, Ickenham, Hillingdon village, Northwood, Yiewsley, West Drayton and Harefield, plus the bordering areas of Iver, Gerrards Cross and Stoke Poges. For a flat roof leaking into the room below we aim to attend a Hillingdon property the same or next working day.
Areas covered
Every area below is part of our regular coverage for this work. Where we have a dedicated location page, the pill links through to it.
Find us
GMG Roof Experts
30 Townfield Road, Hayes, UB3 2EP
Phone: +44 7949 999411
Email: info@gmgroofexperts.com
Hours: 24 hours a day, 7 days a week for emergency call-outs
Questions
The questions below come up most often from Hillingdon homeowners, landlords and businesses.
GRP stands for glass reinforced plastic. It is built up on the roof from layers of glass fibre matting saturated in a catalysed resin, rolled out to remove air and cured into a rigid, fully bonded skin, then finished with a coloured, UV-stable topcoat. It is a genuinely seamless flat roof covering, with no laps or joints across the field of the roof.
Flat and low-pitch roofs: garages and outbuildings, single-storey extensions, dormer tops and cheeks, porches, bay window roofs, and balconies or roof terraces that take regular foot traffic. It is laminated in one piece around rooflight kerbs, upstands and wall abutments, which is where lapped coverings tend to fail.
For roofs with awkward shapes or areas that take foot traffic, often yes. Felt is laid in overlapping layers, so every lap is a potential leak. EPDM is usually a single sheet with few field seams but still has trim and upstand joints. GRP is laminated as one continuous surface with no field seams at all, and it is more rigid, so it suits balconies and walked areas better than a soft membrane.
Not usually the whole deck. We strip the old covering, then cut out and renew only the boards that are soft or delaminated, commonly around the edges and the outlet. Where the roof ponds we add tapered firrings to correct the fall. A sound, dry, rigid deck is what the GRP laminate needs to bond to.
Usually, yes. A crack in the laminate is cut back, cleaned and re-laminated with fresh matting and resin, and a chalked or faded topcoat can be renewed without stripping the roof back to the deck. If the laminate has genuinely failed across a wide area we will say so rather than patch it.
For maintenance access, yes, a GRP roof is rigid enough for occasional foot traffic. For an area used regularly as a balcony or terrace, we finish it with an anti-slip textured topcoat and detail the thresholds and any balustrade fixings into the laminate so the surface stays continuous.
The topcoat is available in a range of colours, commonly grey and brown, and can be matched to the existing trims and roofline. We can talk through the options and a standard gloss or anti-slip finish when we quote.
No hot works or naked flame are involved, the resin cures in place. Most garage and extension roofs are completed in a day or two once access and the deck work are done, weather and curing conditions permitting.
We inspect the roof and the deck in person, then send a written quote covering deck repairs, laminate, trims, outlet, flashings and access. Where a repair is realistic we quote that too. All pricing is on request after that visit, because the deck condition, roof size, upstands and access are the biggest variables. We do not give figures without seeing the job.
We are based in Hayes and cover the whole London Borough of Hillingdon for GRP fibreglass roofing, including Uxbridge, Hayes, Ruislip, Eastcote, Ickenham, Hillingdon village, Northwood, Yiewsley, West Drayton and Harefield, plus the bordering Buckinghamshire areas of Iver, Gerrards Cross and Stoke Poges. Call 07949 999411 to check your postcode.
Call now for a same-day response where the job allows it, or request a written quote following an inspection of the roof and the deck.
A written quote follows every inspection, we put the deck and the falls right first, and we laminate a genuinely seamless GRP roof with the trims, outlet and upstands detailed properly, whether it needs a repair or a full re-cover.
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GMG Roof Experts, 30 Townfield Road, Hayes, UB3 2EP. Email info@gmgroofexperts.com. GRP fibreglass roofing, installation and repair across the London Borough of Hillingdon, including Uxbridge, Hayes, Ruislip, Eastcote, Ickenham, Hillingdon village, Northwood, Yiewsley, West Drayton and Harefield, plus bordering Iver, Gerrards Cross and Stoke Poges.