One of the most important choices you’ll have to make if you’re replacing a flat roof or putting a new roof on an extension or garage is what kind of material to use. EPDM rubber, fiberglass (GRP), and traditional felt are the three most popular choices in the UK. Each one has real pros and cons, and picking the wrong one can cost you a lot more in the long run than you saved at first.
We have used all three materials on hundreds of homes in Yorkshire at Safeway Roofing Yorkshire. This guide honestly tells you how each material works, how long it lasts, and which one is best for your property based on real-life experiences.
EPDM Rubber Roofing
What Is EPDM?
Ethylene Propylene Diene Monomer (EPDM) is a synthetic rubber membrane that has been used on flat roofs since the 1960s. It is put on in big, flexible sheets that are glued directly to the roof deck, with as few seams and joins as possible. It looks and feels like a rubber sheet, which is what it is, and that flexibility is what makes it work so well.
How Long Does EPDM Last?
Most people think that EPDM is the flat roof membrane that lasts the longest for homes and small businesses. A professionally installed EPDM roof can last 25 to 50 years, and there are documented cases of EPDM membranes still working after more than 50 years with little maintenance. The way the rubber is made makes it very resistant to UV rays, ozone, and the temperature changes that make other materials crack and break over time.
Why EPDM Works So Well in Yorkshire
Flat roofs are especially hard on the weather in Yorkshire. Cold winters, constant rain, and wet conditions call for a material that stays flexible and watertight year after year. EPDM is made of rubber, which means it can expand and contract with temperature changes without cracking. This is one of the most common ways that older flat roof materials fail.
Our roofers in Selby often recommend EPDM for garage and extension roofs because it works so well in the wet, changing weather that is common in this part of the country.
Key Benefits of EPDM
- Longest lifespan of any flat roof membrane 25 to 50+ years
- Stays flexible in cold temperatures, resisting cracking and splitting
- Highly resistant to UV radiation and ozone degradation
- Very few seams means fewer potential failure points
- Extremely low maintenance once correctly installed
- Environmentally friendly contains recycled content and is recyclable at end of life
- Lightweight and suitable for most roof structures
Limitations to Be Aware Of
- The black surface absorbs heat, which can slightly increase building temperatures in summer
- Less visually refined than GRP on highly visible roof areas
- Must be professionally installed correct adhesion is critical to performance
Fibre Glass (GRP) Roofing
What Is GRP Roofing?
Glass Reinforced Plastic, or GRP, is more commonly known as fiber glass roofing. EPDM is a flexible membrane, but GRP is a liquid resin mixed with fibreglass matting. It hardens into a shell that covers the roof deck without any seams. The fact that GRP has no joints, laps, or overlaps anywhere on the finished roof is what makes it so special.
How Long Does Fibre Glass Last?
A GRP roof that is installed by a professional usually lasts 30 to 40 years. There are very few places for water to get in because the whole surface is one smooth, continuous piece. Some GRP roofs that were put on in the UK in the early 1990s are still working well, which shows how long-lasting the material is when installed correctly.
Why GRP Is a Popular Choice for Extensions
There is a simple reason why GRP is one of the most popular flat roofing materials in the UK: it lasts a long time and looks clean and professional. You can paint the smooth, hard surface in a number of colors. It looks especially good on modern home extensions, bay window roofs, and dormer tops where the roof is visible from the ground.
Our Roofers in Pontefract team often puts GRP on new-build extensions and home improvement projects where clients want a high-quality finish that won’t need any maintenance for decades.
Key Benefits of GRP
- Completely seamless surface with no joints or overlaps
- Very hard and rigid handles foot traffic without damage
- Cleaner, more attractive appearance than felt or EPDM
- Can be finished in any colour to complement your property
- Extremely resistant to standing water and chemical exposure
- Minimal maintenance required over its 30–40 year lifespan
Limitations to Be Aware Of
- The rigid nature means it can crack if the roof deck beneath flexes significantly
- Cold temperatures during installation can cause curing problems requires skilled, experienced installers
- Not the best choice for very large roof areas where significant thermal movement occurs
Traditional Felt Flat Roofing
What Is Felt Roofing?
For more than a hundred years, bitumen felt roofing, also called torch-on felt or mineral felt, has been the most common type of flat roofing in the UK. There are layers of felt that are soaked in bitumen and either torched onto the roof deck or fixed with machines. The top layer has minerals in it to reflect UV rays. Most people think of this when they think of a flat roof. It is the most well-known flat roofing material.
How Long Does Felt Last?
This is where felt really falls short of EPDM and GRP. A standard felt flat roof lasts about 10 to 15 years, but high-quality torch-on systems put in by experienced roofers can last up to 20 years. The material is naturally less resistant to UV damage, thermal cycling, and long-term exposure to standing water than either of its modern competitors.
The Reality of Felt in Yorkshire
Based on our time in Yorkshire, we have found that felt roofs often don’t last as long as they should. The bitumen felt breaks down faster in the region because of the constant dampness, frost, and temperature changes. We often see problems with felt roofs that are only eight to ten years old, like blisters, cracks along seams, and moss growth.
Every week, our Roofers in Castleford team checks out flat roofs, and the roofs that fail the most often are always felt installations from the early to mid-2010s. If your felt roof is more than ten years old, you should have it checked out before a small problem turns into a big leak.
Key Benefits of Felt
- Lowest upfront installation cost of the three options
- Widely available and easy to source
- Suitable for temporary repairs and low-priority outbuildings
- Any roofer can work with it
Limitations to Be Aware Of
- Shortest lifespan typically 10 to 15 years before replacement
- Prone to blistering, cracking, and seam failures as it ages
- Multiple overlaps and seams create more potential leak points
- Requires more regular maintenance and inspection than EPDM or GRP
- Repeated replacements over time add up to a significantly higher total cost
- Poor environmental credentials compared to modern alternatives
Which Material Should You Choose?
The right choice depends on your property, your priorities, and the specific roof in question. Here is a straightforward guide based on our experience:
Choose EPDM if…
- You want the longest possible lifespan with the least ongoing maintenance
- Your roof is large, has complex detailing, or features multiple penetrations such as pipes and vents
- You want a flexible material that handles Yorkshire winters reliably
- Sustainability and recyclability are important to you
Choose Fibre Glass (GRP) if…
- Appearance matters particularly for visible extensions, bay roofs, and dormers
- You want a completely seamless, hard-wearing surface that can handle foot traffic
- The roof area is under 100m² and has a solid, stable deck
- You want a premium, low-maintenance finish that looks excellent for decades
Choose Felt if…
- You need a short-term solution for a garden building or outbuilding
- The structure itself will be replaced or demolished within the next ten years
- It is a very minor, low-risk repair rather than a full roof installation
We recommend that most Yorkshire homeowners with an extension, garage, or bungalow roof upgrade to EPDM or GRP instead of replacing the felt with something that is the same. They are a better investment for the long term because they last longer and need less upkeep.
A Note on Yorkshire’s Climate and Your Flat Roof
Yorkshire gets a lot of wind, rain, and cold, and all of it falls on your flat roof. In this area, the best materials are those that stay flexible in the winter, don’t let moss and algae grow in wet conditions, and keep their waterproofing properties even when it rains for a long time.
Every month, our Roofers in Leeds team checks out flat roofs all over the city. The results are always the same: EPDM and GRP roofs from the early 2000s are still doing well, while felt roofs from that time have been replaced many times, in some cases more than once.
Taking into account Yorkshire’s weather, the case for a modern flat roofing system gets even stronger. A roof that lasts 30 to 50 years instead of 10 to 15 is not only more convenient, but it also means fewer problems, fewer repairs, and a home that is better protected over time.
Frequently Asked Questions
Can a new membrane be installed over old felt?
Yes, but only if the deck and structure underneath are in good shape. For a clean installation, we usually suggest stripping back to the deck. Overlaying hides possible problems and can make the new system work worse and void its warranty.
How do I know whether my flat roof needs a repair or a full replacement?
If your roof is still fairly new and the damage is only in one spot, a repair might be all you need. If your roof is more than ten years old and has a lot of cracks, blisters, or leaks in different places, it is almost always cheaper to replace it with a new material than to keep patching it up.
Does replacing a flat roof require planning permission?
Most flat roof replacements that are the same as the old one are allowed to happen without needing planning permission. Before you change the design, raise the roof height, or make major structural changes, you should talk to your local planning authority. We can help you with your first survey.
Is EPDM suitable for a green or sedum roof?
Yes. Because it is resistant to roots and waterproofs well for a long time, EPDM is one of the best membranes to use under living roofs. Talk to our team about the right specifications and build-up for your project if you are thinking about getting a green roof.
Get Expert Advice from Safeway Roofing Yorkshire
Our team has been installing and fixing flat roofs in Yorkshire for more than 30 years. We can inspect your roof, suggest the best material for your property, and do the work to the highest standard. We give free quotes, come out the same day, and guarantee the quality of our work on every job.
You can call us for free at 0800 303 2303. We’re open 24 hours a day, 7 days a week, even for roof emergencies.
