Flat RoofingEPDM, GRP & Felt SystemsBarnsley & South Yorkshire
I install and repair flat roofs on extensions, garages, outbuildings and dormers using EPDM rubber, GRP fibreglass and felt, matched to the job and the budget.
23 years on the tools · £2m insured · free, no-obligation survey
Flat roofing across Barnsley and South Yorkshire
Flat roofs are everywhere across South Yorkshire, usually on extensions, garages, dormer windows, porches and outbuildings rather than main house roofs. They take a hard beating from Pennine weather because, unlike a pitched roof, water sits on the surface rather than running straight off, so the covering, falls and detailing all matter more than they would on a steep roof.
I work with three main flat roofing systems: EPDM rubber, GRP fibreglass, and traditional felt. Each has its place. EPDM is a single sheet of synthetic rubber with very few joints, GRP fibreglass forms a rigid, seamless surface once cured, and felt, laid in layers and torched or self-adhesive, is still a solid, cost-effective option for many smaller roofs when installed correctly.
As a sole trader with 23 years in the trade, I fit the system that suits the roof rather than pushing one product for every job. A small garage roof with simple detailing might be perfectly served by a good quality felt system, while a roof with lots of upstands, pipes or a complex shape often works better in GRP or EPDM, which cope with detailing and movement more easily.
Whether it's a leaking felt roof on a 1970s extension, a new flat roof on a garage build, or a full EPDM replacement on a bay window roof, I give a free, no-obligation survey and written quote before any work starts, with a photo report once it's finished.
When you might need this
- Ponding water is sitting on the roof for more than 48 hours after rain
- Felt has blistered, split or lifted at the edges or laps
- Water is coming through onto a ceiling below an extension or garage roof
- The roof is over 15-20 years old and hasn't been replaced since it was built
- You're planning an extension or garage build and need a new flat roof fitted
Recent flat roofing work
What goes wrong with flat roofs
Flat roofs fail in different ways to pitched roofs because standing water and thermal movement are the main enemies rather than wind lift. A lot of the problems I see come down to poor falls, ageing materials or corner-cutting at the original install.
Ponding water
A flat roof with insufficient falls holds standing water for days after rain, which accelerates degradation of felt and can eventually find its way through joints and upstands.
Split or blistered felt
UV exposure and temperature swings make older felt brittle, causing splits and blisters that let water track underneath the covering and into the deck below.
Perished flashings and upstands
Where a flat roof meets a wall or window, the flashing and upstand detail is often the first place to fail, letting water in at the edges long before the main roof surface shows a problem.
Rotten roof deck
Sustained leaks soak into the timber or chipboard deck beneath the covering, causing it to sag, rot and eventually fail structurally if not caught in time.
Common mistakes I see
- Patching a felt roof repeatedly with bitumen paint instead of addressing the underlying fall or joint problem
- Fitting a flat roof with no fall or minimal fall, guaranteeing ponding from day one
- Using the wrong adhesive or primer for EPDM, leading to lifted seams within a few years
- Ignoring small blisters in felt, which grow and eventually split under thermal stress
How I work
My process, step by step
- 1
Free survey
I inspect the existing roof covering, check the falls, look at upstands and flashings, and where possible check from inside for signs of a rotten deck or damp timbers.
- 2
Written quote
You receive a clear written quote setting out which system I recommend (EPDM, GRP or felt) and why, along with the full scope of work and materials involved.
- 3
Preparation
The old covering is stripped back to the deck, any rotten timber or chipboard is replaced, and firrings or insulation are added if needed to correct falls before the new covering goes down.
- 4
Installation
I install the agreed system, whether that's a single EPDM sheet with mechanically fixed edges, a laminated GRP fibreglass laminate, or torch-on or self-adhesive felt layers, with all upstands and detailing properly sealed.
- 5
Sign-off and guarantee
You get a photo report of the finished roof. Flat roof repairs carry a 12-month guarantee.
What you get
Faster installation
EPDM and GRP systems can often be installed more quickly than multi-layer felt on smaller roofs, meaning less time with the roof open to the weather.
Safer, insured work
I'm fully insured with £2 million public liability cover, and I use proper edge protection and ladders when working on garage and extension roofs at height.
Longer-lasting coverings
EPDM rubber in particular is known for coping well with UV exposure and thermal movement, and GRP forms a seamless, rigid surface that resists the joint failures common with old felt.
Prevents costly deck damage
Fixing a small split or blister now, before it soaks into the timber deck, avoids the far bigger job of replacing a rotten deck and the ceiling below it later.
Single point of contact
I survey, quote and carry out the work myself, so you're dealing with the same person throughout rather than being passed between a salesperson and a fitting crew.
Clear written record
A written quote up front and a photo report on completion give you a paper trail of exactly what was agreed and what was done, useful if you come to sell the property.
A closer look at flat roofing systems
Choosing between EPDM, GRP and felt depends on the size and shape of the roof, the level of detailing involved, and what's already there. Here's how I approach each.
EPDM rubber roofing
EPDM is a synthetic rubber membrane usually supplied in large single sheets, which means fewer joints than felt and less risk of a seam failing over time. It's flexible enough to dress around upstands and corners without cracking, and it copes well with the thermal movement a flat roof experiences through a South Yorkshire summer and winter.
It's a good fit for garage roofs, extensions and dormer roofs of most sizes, particularly where there are several upstands or a slightly awkward shape. Once bonded and mechanically fixed at the edges, an EPDM roof needs very little ongoing maintenance beyond keeping it clear of debris and checking edge trims periodically.
GRP fibreglass roofing
GRP (glass reinforced plastic) is laid as a resin and matting system that cures into a rigid, completely seamless surface. Because there are no joints at all, it's a strong choice for roofs with complex detailing, roof lights, or pipes penetrating the surface, since the resin can be worked around these features and finished smooth.
GRP is also a solid choice where the roof will see foot traffic occasionally, such as access to a boiler flue or aerial, since the cured surface is hard-wearing. It does need a dry deck and the right weather conditions during application, which I factor into scheduling the job.
Felt roofing
Felt remains a practical option for many garage roofs, sheds and simpler flat roof shapes, particularly where budget is a factor. Modern felt systems, whether torch-on or self-adhesive, are a considerable improvement on older nailed felt, using multiple layers bonded together for a more reliable waterproof barrier.
The key to a felt roof lasting is correct falls, proper lapping of layers, and careful detailing at upstands and edges; most of the felt failures I get called out to trace back to poor original installation rather than the material itself being unsuitable.
Falls, insulation and deck condition
A flat roof isn't actually flat: it needs a slight fall, usually built in with tapered firrings or insulation, so water runs to an outlet or gutter rather than sitting on the surface. When I replace a flat roof I check the falls are adequate and correct them where the original installation was too flat.
I also check the roof deck, typically timber or chipboard, for rot or delamination caused by past leaks. Any damaged sections are cut out and replaced before the new covering goes down, since laying a new membrane over a weak deck just delays the same problem resurfacing.
Domestic vs outbuilding flat roofs
On house extensions and dormers, I pay particular attention to how the flat roof meets the main pitched roof and brickwork, since these junctions are common leak points and often need lead or GRP flashing tailored to the specific detail of the property.
On garages and outbuildings, the roof is usually a simpler rectangular shape with fewer penetrations, which often makes felt or a smaller EPDM sheet a practical and cost-effective choice, while still giving a durable, weathertight result.
Flat Roofing: questions answered
How much does a flat roof cost?
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Cost depends on the size of the roof, which system you choose (EPDM, GRP or felt), the condition of the deck underneath and access. I give a free, no-obligation survey and a written quote so you have an exact figure before deciding.
How long does a flat roof installation take?
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A typical garage or extension flat roof can often be completed within a day or two, though larger roofs, poor weather, or deck repairs can extend that. I'll give you a realistic timeframe as part of the written quote.
What's the process from start to finish?
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I carry out a free survey, provide a written quote recommending the right system, strip back and repair the deck as needed, install the new covering and detailing, then hand over a photo report of the finished roof.
Is the work guaranteed?
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Yes. Flat roof repairs carry a 12-month guarantee. I'll confirm the guarantee for a new flat roof in your written quote.
How long do EPDM, GRP and felt roofs last?
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EPDM and GRP are generally the more durable options over the long term due to their seamless construction, while a well-installed felt system can also perform reliably for many years if the falls and detailing are done correctly.
Which system is best for my roof?
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It depends on the shape, size and detailing of the roof, plus your budget. I'll recommend the most suitable system for your specific roof during the survey rather than defaulting to one product.
Do you take emergency calls for a leaking flat roof?
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Yes, I take calls every day from 7:30am to 8pm, including for urgent leaks on flat roofs. I don't run a 24-hour service, but I respond to urgent calls within those hours.
Do you cover flat roofing in my area?
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I carry out flat roofing work across Barnsley, Elsecar, Hoyland, Wombwell, Wentworth, Tankersley, Blacker Hill, Harley and West Melton, and further afield including Sheffield and Leeds.
Get a free flat roof survey
Call or message me for a free, no-obligation survey and written quote covering EPDM, GRP or felt flat roofing anywhere across Barnsley and South Yorkshire.
25-year re-roof guarantee · 12-month repair guarantee · £2m insured