You might have heard of EPDM roofing; it’s become very popular in the world of garden buildings, and can be found on top of just about every shed, workshop or garden room with a flat roof. Plenty of timber building companies are raving about how it’s the most cost-effective and long-lasting roofing material out there. But what exactly is EPDM roofing, and how does it measure up against the Scottish climate? We’ll take a look at how EPDM roofing is installed, its benefits and drawbacks, and determine whether this really is the best roofing material for a workshop.
What is EPDM roofing?
EPDM (ethylene propylene diene monomer) roofing is a synthetic rubber membrane used mainly for flat or low-pitched roofs.
How is EPDM roofing installed?
EPDM roofing can be installed in three different ways. Either fully adhered, mechanically attached or ballasted. For a home workshop, it will likely be fully adhered. The membrane is glued down to the entire roof surface of the workshop.
If you do choose a workshop with an EPDM roof, proper installation is critical. Poor installation is the main reason that problems occur with EPDM roofing down the line. I’d recommend choosing a workshop from a supplier or manufacturer who is a specialist in installing this material. This will ensure you get the best performance out of your EPDM roofing.
When installing EPDM roofing, the membrane must have time to relax before it’s fixed to the surface. If this doesn’t happen, then the material can shrink, leading to gaps and water ingress. It’s also important that flashings and trims are installed, and edges are properly secured – especially in Scotland. Edges and seams are going to be vulnerable to wind and rain if not secured properly.
What are the benefits of EPDM roofing?
One of the biggest advantages of an EPDM roof is its long lifespan. It has an expected life of 30 – 50 years. With many good-quality EPDM membranes being backed by a 50-year life span.
EPDM is highly resistant to UV exposure and temperature changes. It’s expected to stay flexible and won’t become brittle even after prolonged exposure to UV or significant temperature drops. This makes it ideal for use as roofing on workshops in Scotland.
Another benefit of EPDM roofing is that it’s usually supplied as a single-ply membrane. The EPDM being one large sheet means there are fewer seams to worry about than alternatives like felt. This allows for superior waterproofing as there are fewer weak spots where water ingress might happen.
EPDM roofing doesn’t have any routine maintenance requirements; however, it is important to check the roof for physical damage every so often.
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What are the drawbacks of EPDM roofing?
While EPDM is a durable roofing material for a workshop, it does have some drawbacks that are worth considering.
Does EPDM vary in quality?
One issue is the varying quality of EPDM on the market. Many garden building companies advertise EPDM roofing, but don’t specify the thickness of the membrane. EPDM can range from 1mm to over 2mm thick, with different thicknesses being best suited to different purposes. For a home workshop, a thickness of between 1.14mm to 1.5mm is ideal. 1.2mm EPDM is a common thickness that’s used for workshops and garden buildings. But if you need your roof to be very resistant to damage, you might want to go a bit thicker than this.
Is EPDM suitable for all roof shapes?
EPDM roofing isn’t usually suitable for pitched roofs, unless the pitch is very low. On a pitched roof, the membrane is under constant tension. This increases the risk of stretching or wrinkling and can let water in. EPDM has been designed for use on flat or low-pitch roofs. On apex or pent workshop roofs, it loses a lot of its durability and waterproofing properties.
How durable is EPDM roofing?
Even though EPDM roofing is a very water-resistant material, if it tears, your building can still suffer from water ingress. Any debris, overhanging trees, fallen branches or even birds that land on the roof can damage an EPDM roof and cause a tear in the membrane.
Small tears in the roofing are easy to patch up without having to replace the whole roof, but the difficulty is spotting the damage early on. Water can seep under the membrane and spread across the roof, causing damage to your workshop before you notice the tear. This is why it’s important to be vigilant and check that there hasn’t been any damage to your EPDM roof.
How aesthetically pleasing is EPDM roofing?
Finally, an EPDM roof isn’t the most aesthetically pleasing. EPDM roofing is more functional than it is decorative, so depending on how you use your workshop, it might not be the right choice for your garden. The smooth black finish can look a little industrial and isn’t as appealing as other roofing materials like shingles. For some workshop owners, this won’t bother you – but if your garden is your pride and joy, you might find that a black EPDM roof is a bit of an eyesore.
Why don’t G&M make Workshops with flat roofs?
At G&M, all of our timber buildings have been carefully designed with the harsh Scottish climate in mind. This is why we choose pitched roofs for our Workshops – with a choice of an Apex or Pent roof. These roofs allow rainwater to easily run off the building, into the gutters and away from the timber cladding.
A flat roof is the perfect place for water to pool, and over time, this damages whatever roofing material is underneath, and eventually will let the water into your workshop. Our Workshops are guaranteed to stay watertight due to their superior specification. They feature a layered timber wall with an air cavity, which stops moisture ingress from reaching the inside of your workshop. At G&M, we need a roof that is in keeping with this watertight design, which is why we don’t make workshops with flat roofs.
What roofing materials do G&M Workshops have?
Our Workshops come with steel box profile roofing, which has a 20-year manufacturer’s guarantee. We love steel here at G&M and use it for the majority of our buildings. Steel box profile roofing provides us with the longevity and durability that we need for our Workshops.
The steel box profile roofing for our Workshops has a polyester coating, which keeps it incredibly waterproof. The combination of the shape of our roofs and the steel box profile roofing allows water to easily run off our Workshops, resulting in long-lasting protection.
Steel box profile is ideal for use in Scotland because it not only protects our workshops against the rain, but wind. High winds can damage roofing materials like felt or even raise the edges of EPDM, whereas steel panels interlock and won’t be lifted or warped by strong winds.
Our steel box profile roofs don’t have any routine maintenance needs; at most, the polyester coating will need to be re-sprayed, but this won’t be for decades.
Is EPDM the best roofing material for a workshop?
While EPDM provides a good level of weatherproofing and durability for workshops with flat roofs, here at G&M, we’ll always choose a pitched Apex or Pent roof with steel box profile roofing to protect our Workshops from Scotland’s weather for years to come.
Come and see our steel box profile roofing in action at our Show Area in Errol, where we have a 3-Tier Workshop on display for you to explore, plus plenty of Sheds, Garages and Garden Rooms.
If you’re interested in finding out more about the G&M Workshop specification, check out this blog post all about our 3-Tier Workshop:
