Single-Ply Membrane: Ethylene Propylene Diene Monomer (EPDM) Thermoset
Single-ply sheet membranes are produced using one of three manufacturing processes: calendering, extruding or spread coating. The membranes may contain reinforcement layers. Common reinforcements for single ply membranes include polyester fabrics or scrims, glass fibre, or a felt or fleece backing.
A finished sheet’s thickness typically is referred to as mil thickness. Common mil thickness for these sheet membranes ranges from 30 mils to 60 mils. Single-ply membranes can be installed fully adhered, mechanically attached or held down with ballast. Most single-ply roof systems do not receive surfacing. In many instances, a combination of attachment methods is used to secure a roof system.
For instance, an insulation may be mechanically attached to the substrate with the roof membrane fully adhered to the insulation.
What is EPDM?
Ethylene Propylene Diene Monomer (EDPM) roofing is an efficient rubber roof style used on low-slope roofing surfaces. It is a synthetic rubber most commonly used in single-ply roofing because it is readily available and relatively simple to apply. It is also called Single Ply Membrane and it is one of the common types of low-slope roofing. It’s been in use on roofs in Canada since the 1960’s. When properly applied, it has a life cycle of 15 to 25 years. It is great for preventing leaks and is often installed for roofs that have problems with weathering, failing joints, and inflexibility. It is relatively inexpensive as well as simple to install as compared to BUR. Compared to conventional built-up roofs, it is also much cleaner and doesn’t emit the odours and fumes that are often associated with built-up roofing systems. (Although Conestoga Roofing uses an “odourless kettle” when it comes to applying BUR.) Vulcanized EPDM is the most common type of EPDM roofing system. Non-vulcanized EPDM is typically used for flashing purposes.
There are Three Methods of Applying EPDM
- Fully adhered EPDM uses water-based or solvent-based adhesives to adhere the EPDM rubber to the substrate.
- Mechanically fastened EPDM is attached to the substrate by manufacturer-approved mechanical methodology.
- Loose-laid membranes are secured only at the perimeters and any penetrations. A ballast of round river rock or concrete pavers is used to hold the materials in place. The river rock is usually installed at a rate of 1000 – 1200 pounds per square (100 square feet of roofing surface) and the pavers typically weigh 20-pounds per square foot. Structural integrity is of paramount importance with a loose-laid roof system. The seams are sealed using either an adhesive or a splicing tape.
EPDM Benefits and Advantages
Highly dependable, economically beneficial, high durability, and high efficiency makes EPDM an attractive option to any building owner looking to a commercial, industrial and institutional roofing contractor for a new roof or an upgrade to the existing roofing system. Additionally, an EPDM roof will often come with a long warranty, low maintenance requirements, low installation labour costs, and generally, garner rather easy code approvals. For regions subject to potentially catastrophic weather experiences, such as hurricanes – EPDM roofs have very high resistance, making them quite practical for those who live in those areas.
EPDM roofs are highly resistant to weathering, ozone, and surface damage. It is flexible in cold weather and still has high fire and heat resistance. You can’t go wrong choosing EPDM for low-slope roofs and flat roofs that need to be waterproof and durable against the harsh Canadian weather.