EPDM A Roofing System for Every Climate 2011-10-03 ED+C Magazine

ClimateMaster

Its been more than two years since Secretary of the U.S. Department of Energy Stephen Chu called for white roofs throughout the United States to save energy and slow down climate change. Thats been long enough for building industry experts to take a second look at the potential pitfalls of this one size fits all approach. Just as important, the secretarys statement has prompted some compelling new studies that look below the surface of the issue, finding there is more to going green than the choice between a dark colored or a white colored roof.

Recent data does, in fact, support the use of white, reflective roofing in the South (ASHRAE zones 1-3). But color-neutral options can be more appropriate in ASHRAE zones 3 and 4 and dark-colored roofs are recommended everywhere else, especially in cold northern climates where dark materials can absorb heat in the winter. There is also data showing that ballasted roofs may save as much energy as reflective roofs. The Department of Energy has put a Cool Roof Calculator on its website to help select a suitable choice.

Life-cycle assessment, or LCA, has also emerged as an important tool in this debate as the roofing industry looks for increasingly accurate ways to measure the true green qualities of its products. Specifically, LCA measures the long-term environmental impact of a product, rather the short-term, immediate consequences. It measures a products environmental costs from cradle-to-grave, factoring in raw material extraction, material processing, distribution, use, repair and maintenance, and disposal or recycling. This approach was used in a recent, state-of-the-art LCA of EPDM systems, one of the most widely used roofing products both in the U.S. and globally. The study results provide unique insights into the environmental benefits of this tried-and-true product.

The LCA study was conducted on behalf of the EPDM Roofing Association (ERA) by the GreenTeam Inc. a strategic environmental consulting firm based in Tulsa, Okla. that specializes in building industry issues. This LCA included all inputs associated with the manufacture and installation of various low-slope roofing systems, including EPDM, TPO and SBS modified bitumen but did not look into disposal and recycling issues (although EPDM is frequently and easily recycled).

The findings showed that both black and white EPDM perform better than many other single-ply and bitumen-based membrane materials in key measurement categories such as global warming, acidification and smog generation. Additionally, study data found that the global warming potential (GWP) of a black EPDM membrane was approximately half that of a white PVC or unsurfaced SBS membrane. The findings also suggest that roof system service life may be a critical factor in determining a materials overall environmental impact. As an example, the non-EPDM systems studied would require up to 54 years to produce an equal annual distribution of the initial embodied GWP impact that EPDM systems achieve in only 15 to 20 years. Put another way, EPDM becomes carbon neutral in less than twenty years, where alternative roofing systems can take more than twice that to achieve the same carbon neutrality.

The GreenTeam data was reviewed by the ATHENA Institute, an internationally recognized non-profit organization. Specifically, the Institutes Impact Estimator is a whole building, life cycle-based decision support tool for use by building designers, product specifiers and policy analysts at the conceptual design stage of a project. It provides a cradle-to-grave Life Cycle Inventory profile for a whole building over its expected life, and is capable of simulating over 1,200 different assembly combinations for approximately 95 percent of the building stock in North America. The new EPDM data is now available on the ATHENA Impact Estimator for Buildings Version 4 software.

As noted above, this LCA of EPDM did not look into recyclability of the product. But theres important news on that front, as well. EPDM rubber now ranks as one of the worlds most recyclable low-slope roofing products. Since 2006, almost thirteen million square feet of EPDM have been removed, transported and recycled from buildings all across North America and Canada, reducing solid waste and pollution. Beyond that, recycled EPDM is having significant impact on the balance sheets of participating companies: More than half of the EPDM recycled nationally has become either cost-neutral or yielded cost savings when compared to traditional landfill disposal.

Specifiers and facilities managers are now seeing roof recycling as an absolute necessity in the years to come. The average EPDM roofing membrane installed on a facility in 2011 may be up for replacement in 30 years. By that time, roof recycling will most likely be a necessity, not an option, due to a growing number of codes that incorporate sustainability requirements. Along with more stringent government penalties, a decline in available landfill space in some parts of the country and rising disposal costs have contributed to the viability of recycling.

Taken together, the scientific findings of the LCA and the explosive growth of recycling show that EPDM is an excellent option for green building present and future. Add in the fact that EPDM is available in both black and white, and this long-time staple of the roofing industry becomes the roofing system of choice to deliver environmental benefits in any and every climate.

ClimateMaster

Its been more than two years since Secretary of the U.S. Department of Energy Stephen Chu called for white roofs throughout the United States to save energy and slow down climate change. Thats been long enough for building industry experts to take a second look at the potential pitfalls of this one size fits all approach. Just as important, the secretarys statement has prompted some compelling new studies that look below the surface of the issue, finding there is more to going green than the choice between a dark colored or a white colored roof.

Recent data does, in fact, support the use of white, reflective roofing in the South (ASHRAE zones 1-3). But color-neutral options can be more appropriate in ASHRAE zones 3 and 4 and dark-colored roofs are recommended everywhere else, especially in cold northern climates where dark materials can absorb heat in the winter. There is also data showing that ballasted roofs may save as much energy as reflective roofs. The Department of Energy has put a Cool Roof Calculator on its website to help select a suitable choice.

Life-cycle assessment, or LCA, has also emerged as an important tool in this debate as the roofing industry looks for increasingly accurate ways to measure the true green qualities of its products. Specifically, LCA measures the long-term environmental impact of a product, rather the short-term, immediate consequences. It measures a products environmental costs from cradle-to-grave, factoring in raw material extraction, material processing, distribution, use, repair and maintenance, and disposal or recycling. This approach was used in a recent, state-of-the-art LCA of EPDM systems, one of the most widely used roofing products both in the U.S. and globally. The study results provide unique insights into the environmental benefits of this tried-and-true product.

The LCA study was conducted on behalf of the EPDM Roofing Association (ERA) by the GreenTeam Inc. a strategic environmental consulting firm based in Tulsa, Okla. that specializes in building industry issues. This LCA included all inputs associated with the manufacture and installation of various low-slope roofing systems, including EPDM, TPO and SBS modified bitumen but did not look into disposal and recycling issues (although EPDM is frequently and easily recycled).

The findings showed that both black and white EPDM perform better than many other single-ply and bitumen-based membrane materials in key measurement categories such as global warming, acidification and smog generation. Additionally, study data found that the global warming potential (GWP) of a black EPDM membrane was approximately half that of a white PVC or unsurfaced SBS membrane. The findings also suggest that roof system service life may be a critical factor in determining a materials overall environmental impact. As an example, the non-EPDM systems studied would require up to 54 years to produce an equal annual distribution of the initial embodied GWP impact that EPDM systems achieve in only 15 to 20 years. Put another way, EPDM becomes carbon neutral in less than twenty years, where alternative roofing systems can take more than twice that to achieve the same carbon neutrality.

The GreenTeam data was reviewed by the ATHENA Institute, an internationally recognized non-profit organization. Specifically, the Institutes Impact Estimator is a whole building, life cycle-based decision support tool for use by building designers, product specifiers and policy analysts at the conceptual design stage of a project. It provides a cradle-to-grave Life Cycle Inventory profile for a whole building over its expected life, and is capable of simulating over 1,200 different assembly combinations for approximately 95 percent of the building stock in North America. The new EPDM data is now available on the ATHENA Impact Estimator for Buildings Version 4 software.

As noted above, this LCA of EPDM did not look into recyclability of the product. But theres important news on that front, as well. EPDM rubber now ranks as one of the worlds most recyclable low-slope roofing products. Since 2006, almost thirteen million square feet of EPDM have been removed, transported and recycled from buildings all across North America and Canada, reducing solid waste and pollution. Beyond that, recycled EPDM is having significant impact on the balance sheets of participating companies: More than half of the EPDM recycled nationally has become either cost-neutral or yielded cost savings when compared to traditional landfill disposal.

Specifiers and facilities managers are now seeing roof recycling as an absolute necessity in the years to come. The average EPDM roofing membrane installed on a facility in 2011 may be up for replacement in 30 years. By that time, roof recycling will most likely be a necessity, not an option, due to a growing number of codes that incorporate sustainability requirements. Along with more stringent government penalties, a decline in available landfill space in some parts of the country and rising disposal costs have contributed to the viability of recycling.

Taken together, the scientific findings of the LCA and the explosive growth of recycling show that EPDM is an excellent option for green building present and future. Add in the fact that EPDM is available in both black and white, and this long-time staple of the roofing industry becomes the roofing system of choice to deliver environmental benefits in any and every climate.

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