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UKFR - ROOFING AND INSULATION SPECIALISTS
Felt roofing has been around for longer, but has EPDM rubber overtaken its usefulness? In this blog, we’ll explain what both systems are and how they compare with each other for different factors. We’ll look at the installation process, versatility, life expectancy, cost, eco-friendly properties and repairability.
| EPDM | Liquid Roofing |
|---|---|
| ✅ Single-ply waterproofing | ❌ Requires multiple layers to be waterproof |
| ✅ DIY-friendly installation | ❌ Requires professional installation |
| ✅ Suitable for green roofs | ❌ Cannot be used on green roofs |
| ✅ Versatile in many applications | ❌ Impractical for overlay systems |
| ✅ 50-year lifespan | ❌ Up to 30-year lifespan |
| ✅ Highly durable, flexible and weather-resistant | ❌ While dense and somewhat flexible, it becomes brittle over time. |
| ✅ Higher upfront cost but cheaper long-term | ❌ Slightly cheaper upfront, but more expensive to install, repair and replace. |
| ✅ Fully recyclable | ❌ Made from crude oil and is far less recyclable. |
| ✅ Safe to harvest rainwater | ❌ Can release harmful oils into the surrounding environment. |
| ✅ Easy to repair | ❌ Difficult & costly to repair |
EPDM rubber (Ethylene Propylene Diene Monomer) is a highly durable synthetic, single-ply membrane used on many flat and low-slope roofing projects, including garages, sheds, porches, garden rooms and more.
EPDM has grown increasingly popular in recent years due to its 50-year lifespan, high flexibility and excellent waterproofing properties, making it a great long-term roofing solution for flat roofs. As it is an impermeable membrane, it can serve as a waterproof layer beneath a green roof system and can also be used on roofs that need walkways or a balcony, we do recommend using walkway tiles or our range of rubber or porcelain tiles.
You can also find out more about EPDM rubber roofing in our Benefits of EPDM rubber roofing blog.
Single-ply roofing quite simply means roofing applied in a single layer. EPDM is a great example of an effective single-ply roofing system as it’s fully waterproof in one sheet.
This is one of the many advantages of EPDM, especially in comparison to felt roofing, which is a built-up system.
Felt roofing is a roofing system made from modified bitumen felt, which is a combination of asphalt and fibres.
Felt roofing is known under many different names, including modified bitumen, bitumen roofing, bitumen felt, mineral felt, asphalt flat roofing, bitumen sheet roofing and torch-on felt. The name “torch-on felt” comes from the installation process, which involves using a flame torch to heat the felt so that it adheres to the roof deck.
The new modified bitumen has evolved from an old roofing method known as built-up roofing.
Built-up roofing is achieved by applying multiple layers of asphalt between ply sheets to create a watertight layer. Torch-on felt is a great example of a built-up roof, as it should be installed in multiple layers to increase its durability. The layers often include fibreglass to increase the strength of the whole system.
Torch-on roofing can be used as a single-ply roofing application; however, we do not advise this, as bitumen felt installed in one layer doesn’t provide durability.
Yes and no.
Bitumen roof felt is still used by many contractors today. However, if it was installed many years ago, it will likely be suffering from weathering, as it’s brittle and easily tears and rips. When this happens, it can lead to dampness and leaks, which no one wants. Replacing roof felt is often complex and costly, as it can only be repaired by a trained installer.
Despite it still being used in flat roofing, there are easier-to-install and repair alternatives, such as EPDM, which also has a longer life expectancy in comparison.
There are many factors to determine which is better.
Throughout the blog, we will cover the following areas and answer these questions.
Is EPDM or felt easier to install?
EPDM and felt are installed in very different ways.
EPDM is a cold-applied system, meaning no heat or naked flames are needed, and instead, you simply bond the membrane to the roof deck using adhesive. EPDM is a single-ply system, which means it’s installed in just one sheet.
Felt, on the other hand, is a torch-on system which requires an open flame to melt and adhere the sheets together and to the roof deck. Felt is a built-up system which is installed in multiple layers.
EPDM is a single-ply membrane, which means you only need to install one sheet. Felt, on the other hand, is a built-up system, meaning it requires multiple layers before it’s fully waterproof.
EPDM can be supplied as a large single sheet, cut to your exact measurements, or in roll form, whichever suits your project best. Felt is limited to roll application only, which increases the number of seams and, in turn, the risk of water ingress.
Overall, EPDM is the easier system to install as it’s faster, safer and DIY-friendly.
Which is more versatile, felt or EPDM?
EPDM is vastly more versatile compared to felt.
EPDM can be used across many projects, from garden sheds and garages to green roofs and overlay systems. All EPDM membranes are suitable for use beneath a green roof when correctly installed, and certain systems like RESITRIX can even be laid over existing roofing, saving time and money on removal.
Some heavy-duty roofing felt can occasionally be used below a green roof; however, most torch-on systems have joins that are not strong enough to resist root penetration. Torch-on felt is also less commonly used in overlay systems due to the welding required.
Make your installation easier with our bespoke EPDM roof kits:
Does felt roofing or EPDM rubber have a longer life expectancy?
EPDM lasts significantly longer compared to felt.
EPDM rubber has a lifespan of over 50 years, making it the longest-lasting flat roof system on the market. It also has an incredibly long warranty, with some of the most basic systems on the market offering warranties between 20 and 35 years, and some also have BBA certificates of up to 35 years available.
EPDM far outlasts the older and most basic felt roofing systems that have a shorter life expectancy of between 10 and 15 years.
There have been recent advances in felt roofing, which has seen the life expectancy for the best roofing felt get up to 30 years. However, it is still inferior to EPDM, which has a longer lifespan.
What is more durable, felt roofing or EPDM rubber?
EPDM is more durable than felt roofing.
EPDM is one of the most durable flat roofing materials available. It’s highly flexible, UV-resistant, and built to handle extreme temperatures, meaning it won’t crack or split with weathering.
Bitumen roof felt is a dense and somewhat flexible weather-resistant product; however, over time, it can become brittle and more susceptible to damage from leaks.
Despite bitumen roof felt being a hardy product that will waterproof your roof, EPDM outperforms it over time.
Is felt or EPDM more cost effective?
A cheaper upfront cost doesn’t mean it will be cheaper in the long run. This is the case with felt and EPDM. Felt is cheaper initially, but over time, EPDM is significantly more cost-effective.
Upfront material cost
Felt is typically the cheaper material compared to EPDM, which will appeal to those on a tight budget; however, you also need to factor in installation.
Installation costs
Because EPDM is cold-applied and straightforward to fit, it can be installed by yourself if you’re a confident DIYer. This would make it the cheaper option for you. Felt, on the other hand, requires specialist tools and a qualified installer due to its multi-layer application, which makes it more expensive in comparison.
Long-term value
As we mentioned earlier, EPDM has a lifespan of over 50 years, which is more than double that of felt. That means fewer replacements, less maintenance, and lower costs over time. When you factor all of this in, EPDM is comfortably the more cost-effective choice in the long run.
Find out exactly how much your EPDM roof will cost with our EPDM Calculator.
We’ve built this ourselves, and it covers everything we need from you to provide you with an accurate quote. Simply enter your roof size, trim types, deck type and system type, and we’ll tell you exactly how much it will cost.
Is EPDM or felt more environmentally friendly?
Over the past few years, the construction industry has been taking steps towards a greener future and away from harmful products.
Recyclability
EPDM is widely regarded as one of the most sustainable flat roofing systems available. Most EPDM membranes are fully recyclable, making them a responsible choice at the end of their lifespan. Felt, on the other hand, is made from bitumen derived from crude oil – a hazardous material that is far less recyclable by comparison.
Impact on the environment
EPDM is a non-toxic material, meaning it will not leach harmful chemicals into rainwater runoff. This actually opens up the option of rainwater harvesting, which is a popular and practical way to reduce water consumption. Its non-toxic nature also makes it an ideal waterproofing layer beneath a green roof system.
In contrast, torch-on felt can release harmful chemicals into the surrounding environment. This is why EPDM is the superior product environmentally.
Is felt or EPDM better for a DIY project?
If you’re planning a DIY roofing project, EPDM is the obvious choice. Its single-ply design keeps installation straightforward, and there’s plenty of support available, from online step-by-step guides and videos to our own shed roof kits, which come with the exact amount of product you need for the job.
Felt, on the other hand, is not well-suited to DIY. The torch-on installation method involves a naked flame, which makes it a job best left to a skilled tradesman.
Learn how to install an EPDM roof
Is felt or EPDM easier to repair?
Should damage occur, EPDM is straightforward to repair. A split or puncture in the membrane can be fixed quickly and cheaply using an EPDM rubber roof repair kit, which comes with everything you need to get the job done.
Felt is a different story. Repairs to a felt roof really do need to be carried out by a specialist to ensure they’re done correctly and safely, and the cost of refelting a roof can be high once you factor in the tools and labour involved.
Therefore, EPDM is the easier system to repair. If you currently have a felt roof that needs repairing, it is worthwhile considering a switch to EPDM.
If it hasn’t been clear already from reading this blog, EPDM is superior to felt roofing. While a mineral felt roof will do the job at the end of the day, EPDM will outperform and give you the best bang for your buck throughout its life.
