The best single ply material to install on a low slope (flat) roof is EPDM? "If your building has a flat roof, you should seriously consider an EPDM membrane roof ". For more information log onto www.epdmroofs.org
Historical Timeline
EPDM membrane formulations have remained relatively constant for the past 40 years, with roof systems installed in the 1970s still performing well. Even so, EPDM manufacturers remain committed to continuous product innovations. In response to technological advancements, membrane research and contractor requests for more ergonomic products, EPDM accessory products continue to evolve in order to meet the demands of the industry.
The innovation of seam tapes in the 1980s to replace liquid adhesives has resulted in reduced reliability on contractor workmanship, greater productivity for the contractor and enhanced performance for the roof system and building user. Self-adhering components (components that have factory-applied adhesive tape) have increased roof system quality, especially in more problematic areas such as flashing installations.
Installation equipment has evolved as well. Ergonomic innovations have reduced crew force fatigue and have enhanced roof system installation and performance.
Following over 15 years of off-market testing to verify performance, 90 mil EPDM membranes have recently been introduced into the market. This highly puncture resistant and tough membrane offers the thickest layer of monolithic waterproof protection in the roofing industry.
The 90 mil EPDM roof systems are redefining the roofing industry and the expectations of architects, roof consultants and building owners. Thirty-year warranties based on historical performance are now available. This is the only long-term performance guarantee in the roofing industry, and can include warranty coverage for punctures, hail and wind speeds up to 100 mph.
White EPDM combines the high-performance standards of traditional EPDM with a highly reflective, environmentally friendly surface designed to cut energy costs. In addition to the oils and the polymers used to make an EPDM membrane, another ingredient is added to the mix to enhance UV resistance. With white membrane titanium dioxide is typically used to reflect UV rays and prevent it from attacking the polymer. When used appropriately, usually in warm climates, white EPDM can reduce air-conditioning costs without sacrificing durability of the roofing system. Because of its reflectivity, white EPDM is installed using mechanically attached or fully adhered systems.
The answer to your question depends on several factors, such as: geographic location of the project, makeup of the roof deck being applied to, your insurance provider’s requirements (depends on the value of what you are trying to protect inside the building), wind uplift code requirement, etc.
“White roofs” should only be considered in warmer climates where the number of “cooling days” far exceeds the number of “heating days”. For example: in the Northern climates, a black roof will absorb solar energy and release some of that into the building. A white roof would reflect a significant amount of solar energy resulting in a higher energy cost to heat the building (in a cold climate), but would be an excellent option in the Southern warm climates. As a frame of reference: Kansas City has more heating days than cooling days in a typical year. As a result, white roofs are advantageous in the summer but less advantageous from fall, through winter, and well into spring creating a greater heating demand from within the building$$$.
As stated in previous answers the best single-ply roof system depends on numerous factors including climate temperature, wind exposure and geographic location; however, the main difference between single-ply roofing systems are the different ways to seal the seams and the material composition. EPDM can be either fully-adhered (attached with glue and seam tape), which is the stronger yet more expensive option, or mechanically-attached (screwed in at the seams with no field adhesion). Mechanically-attached is cheaper but can experience “flutter” from the wind and is more exposed to wind damage. EPDM is rubber-based so it is known for being flexible and strong with better impact resistance.
TPO and PVC are thermoplastic roofing systems as opposed to rubber-based. Their seams are welded. TPO seams are welded a single time on the outside while PVC seams require an inner weld followed by an outer weld. These seams are then probed for defects. These products are known to be more reflective of heat and have a chemical resistance that cannot be matched by EPDM.
Another huge factor to consider is the r-value attained from the thickness of your roof insulation. This can diminish energy output by retaining interior temperature.
In conclusion, all of these systems are effective if installed properly, and are sold by many different manufacturers. The main point to look for on any roof is a complete (manufacturer inspected) warranty that can cover you if there are any human-made damages. These range from 15 to 30 years depending on the roof system and manufacturer. A commercial roof is a big investment that is extremely important to retaining the value and integrity of any building, make sure yours is done properly and up to the manufacturer’s par. Hope this information is helpful.
