EPDM roofing was developed in the 1960s as a response to the demand for alternative roofing systems. With the fuel shortages and the oil embargo of the 1970s, roofing manufacturers were faced with a shortage of crude oil necessary to produce conventional roofing products. There are three main types of EPDM roofing: Standard EPDM, Fleece-backed EPDM and Reinforced EPDM.
WHAT IS EPDM ROOFING?
EPDM roofing (Ethleyne Propylene Diene Monomer) is a single-ply rubber roofing system. It has the appearance and feel of a tire inner tube. It is generally used on flat or gently sloping roofs. It easily surpasses roofing material available today in terms of performance characteristics and long-term weatherability. It is UV resistant and has a flexibility well past
-60 degrees Celsius which makes it an excellent choice for the Canadian climate. EPDM roofing membrane weathers better than any other roofing system. Conventional roofing systems usually require some form of maintenance after only a few years of service. EPDM roofing systems show no similar signs of deterioration with aging and can last up to 30 years. It can be installed much faster than conventional systems resulting in lower cost.
The two leading manufacturers of EPDM are Carlisle and Firestone though there are many others such as US Intec, Goodyear and Lexcan. The process for manufacturing EPDM roofing is relatively standard. It is a synthetic rubber membrane made of EPDM polymers compounded with pure carbon black which is one of the most weather resistant compounds known. The use of carbon black makes it resistant to ozone, UV, and aging. EPDM roofing is manufactured in large rolls from five to fifty feet in width and up to two hundred feet in length, resulting in fewer seams and less installation time. Lexcan EPDM roofing comes in sheet sizes up to 10,000 square feet and most roofs can be covered with one sheet.
TYPES OF EPDM ROOFING
Most manufacturers offer three different types of EPDM roofing: standard, fleece-backed and reinforced. These are available in a variety of thickness (.045 to .060). They are complimented with a wide range of seaming and flashing accessory products. EPDM roofing costs between $4.00-$6.00/sq. ft. Tar and ply roofing costs about the same but does not have the life expectancy or ease of application that EPDM roofing has. Roll asphalt roofing costs around $1.70/sq. ft., and is the most vulnerable of flat roofing systems.
Standard EPDM Roofing can be used on anything from a dog house or trailer roof to a commercial building. It is extremely fatigue and puncture resistant and has a life expectancy of at least twenty years. Many EPDM roofs installed in the 1960s are still performing without problems. It is available in black or white. White is typically used on buildings where there are concerns about thermal heat transfer or about sweating under the membrane. White EPDM roofing can be up to 80 degrees cooler than black, which can translate to significant energy savings in an air-conditioned building. Black EPDM roofing can be painted white with water-based acrylic paint.
Standard EPDM roofing accounts for about 30% of all commercial roofing materials. It remains the most popular choice for industrial use. Thousands of millions of square metres of EPDM roofing have been successfully installed worldwide over the last 30 years. 200 million square metres are installed annually, making it the most widely used roofing system in the world. It is lightweight and easy to install making it ideal for do-it-yourself projects or can be professionally installed for larger applications.
Fleece-backed or Poly-Bond Felt-Backed EPDM is a versatile single ply system for directly adhering to challenging roof decks including concrete, gypsum, tectum and metal roofs. It is thicker than standard EPDM roofing making it more puncture resistant. Fleece-backed membranes incorporate a conventional EPDM bonded to polyester fleece allowing it to better withstand abuses common on less-controlled roof settings such as a school roof where access is not limited or where a roof may be exposed to heavy traffic loads. The polyester backing provides a medium to bond the membrane into polyurethane adhesives.
Reinforced EPDM Roofing such as Firestone RubberGard combines the flexibility of EPDM rubber and the high-tensile strength of polyester fabric that is manufactured right into the membrane. This combination provides the best puncture resistance and maximum resistance to weather. Reinforced EPDM roofing stretches to over 300% beyond its original dimension and can easily accommodate typical building movement. This is the most impressive elongation among single-ply roofing membranes and is clearly superior to the 2% to 3% elongation offered by traditional built-up roofing systems. It remains flexible at temperatures down to -45 degrees Celcius. This type of EPDM roofing is the best option for a roof with heavy traffic or one that is vulnerable to high winds or extreme temperatures. RubberGard is guaranteed against leakage for twenty years. Only approved installers that have proven they can maintain the high standards required are allowed to use the materials and be recognized as an authorized contractor.
EPDM roofing systems can be installed in various ways. The three most common are ballasting with smooth stones, fully adhered with adhesives or mechanically attached to the roof deck with fastening devices.
Ballasted EPDM Roofing Systems utilize large sheets held in place by smooth river stone or pavers. This system is extremely versatile and available in several variations. The use of stone is most economical and is most aesthetically pleasing. The sheets are usually laid over polystyrene insulation, which is lightweight, economical and energy efficient. No adhesives are used in this process and this method is not recommended where wind is a problem or when the roof may not be able to support the extra weight of the ballasts.
Fully Adhered Roofing Systems remain the most common choice of many architects, owners and roofing contractors. They are the easiest to install and have fewer problems than the other two. A special liquid rubber adhesive is applied to the roof and can be used without the need of fasteners or anchors. This system is lightweight (less than two pounds per square foot with most applications). It is easy to repair and the most inexpensive of the three systems.
Mechanically Fastened Roofing Systems are extremely versatile and can be installed on steep slopes. The EPDM sheets are fastened to the substrate with mechanical fasteners. This system adapts itself well to curved roofs. This system is most often used with reinforced EPDM because it is resistant to punctures/tears and wind fatigue at anchors.
Repairs to large EPDM roofing installation should be done by a certified professional to ensure that the warranty protection remains valid.