EPDM roofing shares slide while TPO grows in US

ERJ staff report (R&PN)

AKRON--Rubber single-ply membranes hold a firm place in the low-slope, commercial roofing market, but their share has fallen in recent years, in large part because of the growing popularity of reflective or white membranes.

EPDM has been around as a major roofing membrane material for more than 40 years, and manufacturers continue to develop new products based on it, said Bill Tippins, EPDM product manager for Firestone Building Products Co. Firestone and competitor Carlisle SynTec Inc. are the top manufacturers in the rubber-roofing market.

However, the mature material started to decline in overall market share by about 5 percent annually over the past five years, while thermoplastic polyolefin membranes-the most popular of reflective or “cool” roofs-have seen double-digit growth, Tippins said. “Absent any substantial innovations, I expect the trend to continue.”

Making a choice

EPDM has developed as one of the most trusted and durable of single-ply roofing membranes, Tippins said. Single-ply roofing is made of a variety of materials, including EPDM, TPO, Hypalon, polyvinyl chloride, and elastomer- and plastic-modified bitumen.

Contractors embrace the ease of installation because of the flexibility and seam technology of EPDM membranes, he said, and customers find the weatherability, low maintenance and exceptional life expectancy to be an excellent value.

The material is also resistant to ozone, abrasion, hail, extreme heat and fire, and ultraviolet radiation, manufacturers claim.

But Tippins said TPO is a very good roofing membrane as well, particularly in regions of the country where there are more cooling degree days-when cooling equipment is used-than heating degree days, when heating equipment runs.

“In these regions, the building owner gets the benefit of having a reflective roof, which in turn keeps their building cooler, thus requiring less air conditioning expense,” he said.

Compared with EPDM, TPO's desired attributes include heat-welded seams, heat reflectivity, weatherability and dimensional stability.

Traditional rubber membrane manufacturers such as Firestone and Carlisle have embraced TPO in the past decade. Carlisle built a TPO membrane facility in 1998, and added a second plant in 2005.

Indianapolis-based Firestone bought its first line in 2002 and now operates three U.S. TPO manufacturing sites.

Competitors such as Johns Manville and GAF Materials Corp. also have added TPO capacity over that time frame.

And in 2006 Firestone purchased the GenFlex Building Products unit from Omnova Solutions Inc. to boost its line.

Carlisle and Firestone each have two EPDM facilities in the U.S., and Tippins said his company's capacity is positioned for market growth in the near future. He doesn't anticipate any new capacity for EPDM on a global basis within the next five years.

There is a considerable amount of excess capacity in the marketplace for TPO, too, he said, and it will take some time-perhaps two years or more-to recover from the economic recession. “When that eventually happens, we would certainly contemplate the need for additional TPO capacity.”

Facing down the challenge

The main issues and concerns of the rubber roofing industry are shared by those of other roofing products, said Linda King, managing director of SPRI, a trade organization representing the single-ply roofing industry: in particular, how to continue to provide a quality product that addresses the needs of the building owner.

While rubber roofing's top players are prevalent in TPOs as well as EPDM, they believe that white materials' benefits are limited, particularly on a region-by-region basis.

Some roofing manufacturers-most of which only offer reflective materials-promote reflectivity as energy-efficient regardless of climate zone, said Robert Reale, manager of Carlisle Creative Services, which, like SynTec, is a Carlisle Construction Materials subsidiary.

But the Carlisle, Pa.-based firm is committed to promoting the appropriate material for each climate zone, he said.

Tippins agreed, saying that roof designers are taking their cues from studies showing white roofing covers reflect solar radiation back into the atmosphere, keeping the system cooler and ultimately reducing building energy usage through lower air conditioning demand. But this is not the case for all areas of the country or world, he said.

“In regions where there are more cooling degree days than heating degree days, white roofing options are a perfectly reasonable choice,” he said. “However, where the opposite is true, black/non-reflective materials make more sense. In these scenarios, black EPDM absorbs solar radiation, heats the roofing system and ultimately reduces energy requirements.”

Using data from the U.S. Department of Energy, Reale looked at the ratios of heating degree days to cooling degree days in U.S. cities like Boston; Grand Rapids, Mich.; and Albuquerque, N.M.

The ratio was 14.3 to 1 in Grand Rapids and 9 to 1 in Boston, and even in a southwestern city like Albuquerque, the ratio was 3.6 to 1.

Because of the overwhelming amount of heating degree days and positive winter heat gain in these locations, in all instances “energy consumption and carbon emissions are fewer with a dark roof surface than with a reflective surface,” he said.

Various organizations and regulatory agencies make broad-ranging recommendations without considering all the available facts, Tippins said, and there is legislation-in the form of the Waxman-Markey bill-under consideration that includes requiring all roofs to be “green” or covered with white or reflective products.

EPDM manufacturers, however, are requesting that legislators consider the negative impact the law would have on building owners in cooler regions of the country if forced to install less energy-efficient roofs, he said.

'Significant demand'

While EPDM has lost market share in the past few years, it still is preferred as a roofing material by many contractors overall and in selected regions.

The National Roofing Contractors Association's 2008-09 market survey showed that EPDM had nearly 30 percent of the share in low-slope roofing new construction sales for 2008, placing it first on a long list of materials for the category. TPO was second with 22.3 percent.

In reroofing, EPDM was number one as well, with 27.1 percent, followed by TPO with 19.4 percent.

However, the survey's projections for this year indicate the gap narrowing to 27.5 percent for EPDM and 26.1 percent for TPO in new construction, and 26.3 percent for EPDM versus 21.5 percent for TPO in reroofing.

The market share advantage has shrunk in regional breakdowns as well, the survey indicated, even in some cold weather and seasonal areas such as the Mid-Atlantic and East North Central.

Single-ply membranes appear most frequently in mechanically attached and fully-adhered roofing systems, according to SPRI data from 2008. And fully adhered and ballasted roofing are two single-ply applications where EPDM is still the product of choice, according to Tippins.

Few reinforced thermoplastic products such as TPO or PVC are fully adhered, and even fewer are ballasted, he said.

EPDM also can be used in reflective roofing membranes.

Firestone, for example, makes a white EPDM product under its RubberGard branding called EcoWhite, which installs similarly to black EPDM and meets reflective membrane specifications, Tippins said.

The company also offers a white coating called AcryliTop that adheres well to black EPDM. Those products allow Firestone to “compete more effectively in regions of the country that have higher CDDs than HDDs,” he said.

TPO eclipsed EPDM in square foot-age sold in the U.S. roofing market in 2008 and is expected to gain market share from its competitors over the next five years.

EPDM will continue to be challenged and maligned as a non-white membrane-though this perspective isn't rational-and may well continue to decline in the roofing market absent any substantial innovations, Tippins said.

Despite the relative gloom, EPDM's successful history and status as a leading choice in several applications and geographic regions support its strong presence in the market, he said. “It doesn't appear that TPO will be giving up its crown any time soon, but a significant demand for EPDM will remain.”

From Rubber & Plastics News (A Crain publication)