Improving Disaster Mitigation Strategies

This past January, the National Institute of Building Sciences (NIBS), a non-governmental, non-profit organization, reported that for every dollar spent on mitigation efforts to protect the built environment from the ravages of natural disasters, six dollars could be saved. These findings were part of a follow-up to the widely cited benefit-cost ratio of four to one in a comparable study by NIBS more than a decade ago. For this most recent study, NIBS reviewed the outcomes of 23 years of mitigation grants funded by FEMA, HUD, and the U.S. Economic Development Administration.

On the same day that the NIBS study was released, FEMA released its draft National Mitigation Investment Strategy to provide a “national approach to investments in mitigation activities and risk management across the United States.” According to the FEMA draft, the final investment strategy will be grounded in three fundamental principles: (1) catalyze private and non-profit sector mitigation investments and innovation; (2) improve collaboration between the federal government and state, local, tribal and territorial governments, respecting local expertise in mitigation investing; and (3) make data- and risk-informed decisions that include lifetime costs and risks. The investment strategy’s overarching goal, according to FEMA, is to improve the coordination and effectiveness of “mitigation investments,” defined as risk management actions taken to avoid, reduce, or transfer risks from natural hazards, including severe weather.

FEMA invited comment on its draft report and will publish its final strategy in November. Given the potential impact of this report on the built environment, and the industries that work to incorporate resilient strategies, the EPDM Roofing Association (ERA) submitted feedback to FEMA. ERA represents Johns Manville, Firestone Building Products, and Carlisle SynTec Inc., the three EPDM manufacturing members of the association, whose businesses span the globe. EPDM roofing membranes have been one of the leading commercial roofing materials in the country for the past 40 years, and the companies’ knowledge of the role of roof performance in achieving a building’s resilience is unparalleled.

In our response to FEMA, ERA noted that we appreciate the role that the built environment plays in a comprehensive disaster mitigation strategy. As an organization, ERA has invested time and resources to gather and provide state-of-the-art information about various approaches to creating a resilient built environment. This past year, ERA established a new microsite, EPDMtheresilientroof.com, to provide the roofing industry with a one-stop source for information about resilience. As part of information gathering for this site, ERA staff and members have visited three of the premier research facilities in the country: Oak Ridge National Laboratory, the Insurance Institute for Business and Home Safety (IBHS), and the National Center for Atmospheric Research. These visits were also devoted to gaining a fuller understanding of the intersection between public and private progress in research and development.

At the outset of our response to FEMA, ERA commended FEMA for its issuance of the draft strategy, and supported all the recommended goals as desirable as risk management strategies to be implemented at the private and public sector levels. However, given ERA’s experience with building performance, we also focused our comments on two of the specific recommended strategies in the published draft.

First, ERA responded to the recommendation that “Federal departments and agencies should ensure up-to-date building standards are used for federal building projects and could incentivize state, local, tribal and territorial governments receiving federal aid for building projects to adopt and enforce, at a minimum, the most current version of model building codes.”
Commenting on this recommendation, ERA pointed out that a review of hurricane and related weather catastrophic events demonstrates that the better the building quality and the better the building codes, the better the performance of the community. While there has been substantial improvement in many states across the country, adoption and compliance pose significant hurdles for overall performance in disaster events. The urgency of this cannot be overstated. Part of this effort to upgrade the building codes and consequently overall resilience must focus on the quality of materials, installation, and inspection of final construction to ensure compliance by local authorities.

The experiences of the roofing industry in its inspection of many disasters over the years have confirmed that a well-installed, inspected, and well-maintained roof is a linchpin of overall building resilience. ERA believes that federal funding to the states to allow for the kind of technical assistance that enhances code quality and state and local compliance programs necessary to achieve physical and community resilience should be provided.
Additionally, ERA responded specifically to the recommendation that “Public sector entities should focus more on rebuilding better as well as rebuilding quickly following damage caused by natural disasters.”
ERA pointed out in its response that this recommendation to achieve rebuilding better buildings quickly following damage caused by natural disasters is among the most important in the report. As FEMA Deputy Director Roy White has pointed out in several presentations focused on resilience, it makes no sense for the agency to fund rebuilding of a destroyed facility to standards that existed when the original building was constructed with the likelihood that it would not be able to withstand another weather event beyond historic norms. Consequently, ERA recommends that FEMA and HUD need to have authority and appropriations to ensure that rebuilding is done with an eye towards future — not historic — climate conditions. This is in recognition that the original basis for many buildings that then are destroyed has been dramatically changed by recently evolving weather patterns. In addition, as the FEMA and NIBS study recently demonstrated, there is a payback to the government of a 6 to 1 ratio for investing in rebuilding to a more resilient standard.

There are many, many elements of the draft strategy that ERA supports; however, we believe the two mentioned above are particularly within our expertise and with which we are very familiar. We look forward to the final mitigation strategy report from FEMA, due to be released in November, and we encourage FEMA to incorporate our recommendations to ensure that the value of investment in resilience be realized to the fullest extent possible.

Research Centers Provide Valuable Information About Roof Performance

The Insurance Institute for Business and Home Safety Research Center evaluates construction materials and systems in its state-of-the-art testing laboratories. Photos: Insurance Institute for Business and Home Safety.

Until early October of this past year, Chester County, South Carolina, was home to a small, single-story house, similar to thousands of houses across the United States, but unique in almost every way.

What made this small structure one of a kind? The house sat inside the large test chamber at the Insurance Institute for Business and Home Safety (IBHS) Research Center, dwarfed by the six-story chamber’s cavernous interior. The house was built, in fact, to be destroyed.

On Oct. 5, the staff of the IBHS Research Center focused the test chamber’s intense destructive wind power, generated by 105 super-sized fans, on the small structure. Prior to the test, the center had digitized the wind record of an actual storm, and the wind speeds produced by the fans were varied accordingly. In the case of the simulated storm in early October, wind speeds were increased in three phases, up to 120 miles an hour. The house experienced significant damage to its walls and interior, and the garage door was ripped off. But the roof, built to IBHS’ recommended standards, held firm.

The IBHS research facility, which opened in 2010 and is funded by property insurers, evaluates various residential and commercial construction materials and systems. The lab is the only lab in the world that can unleash the power of highly realistic windstorms, wind-driven rain, hailstorms and wildfire ember storms on full-scale one- and two-story residential and commercial buildings in a controlled, repeatable fashion.

The mission of IBHS is to reduce the social and economic effects of natural disasters. And much of its research, like its attack on this small house last October, has focused, at least in part, on the resilience of roofs. As IBHS President and CEO Julie Rochman has noted, “The roof is your first line of defense against anything Mother Nature inflicts … and during a bad storm your roof endures fierce pressure from wind, rain, and flying debris.”

Educating the Industry

In May of 2017, the EPDM Roofing Association (ERA) launched a microsite to help educate the construction industry about the increasing need for resilience in the built environment, and the contributions that EPDM roofing membrane can make to a

IBHS conducts hail research in the Laboratory Building for Small Tests, where hailstones of various sizes are recreated and propelled against roof samples. Photos: Insurance Institute for Business and Home Safety.

resilient system. That effort came in response to the increasing number of extreme weather events. Since last May when ERA first launched its resilience microsite, the pattern of extreme weather has continued unabated, in the form of wildfires throughout the west which were exacerbated by extreme heat, and Hurricanes Harvey and Irma which left devastating floods and wind damage in their wake.

For more than a decade, ERA leadership has supported research about factors that contribute to the resilience of EPDM as a membrane, and how it best functions in various roofing systems. More recently, ERA has invested in site-visits to leading research organizations that generate science-based data about resiliency in building systems, first to Oak Ridge National Laboratories, near Knoxville, Tennessee, and then to the National Research Energy Laboratories (NREL) in Golden, Colorado. Given the complementary goals of ERA and IBHS to help support the creation of truly resilient buildings, ERA leadership welcomed the opportunity to visit the South Carolina research facility.

Analyzing Hail Damage

The hail research at IBHS was of special interest to ERA, given ERA’s research that has consistently shown that EPDM membrane offers exceptionally strong resistance against hail damage. Based on field and test data sponsored by ERA, EPDM roof membranes outperform other roof systems in terms of hail protection. In 2007, ERA conducted tests which showed that EPDM roofing membranes did not suffer membrane damage and avoided leaking problems endemic to other roofing surfaces in similar circumstances. Of the 81 targets installed for that research over different surfaces, 76 did not fail when impacted with hail ice balls up to three inches in diameter. Perhaps most importantly, the impact resistance of both field-aged and heat-aged membranes in this test also clearly demonstrated that EPDM retains the bulk of its impact resistance as it ages.

The IBHS Research Center’s super-sized fans can recreate winds to measure their effects on full-scale one- and two-story residential and commercial buildings. Photos: Insurance Institute for Business and Home Safety.

Using this ERA-generated research as a starting point, ERA leadership travelled to IBHS with specific questions in mind, including: What has IBHS research revealed about the impact of hail on various types of roofing membranes and systems? Does the IBHS research reinforce or contradict ERA’s findings? What are the next questions to be asked about the damage that hail can do, and are resilient systems cost-effective?

Hail research at IBHS is conducted in the Laboratory Building for Small Tests, a compact structure with equipment appropriate to replicate large hailstones and hurl them at roof samples. As part of its research, IBHS has worked with the National Weather Service to assess the geographic locations threatened by hail. Individual storms have long been recognized as creating widespread and expensive destruction, but is hail a threat that is confined to just a few specific geographic areas of the country?

In fact, more than 75 percent of the cities in the United States experience at least one hailstorm a year, and the risk extends across the country to all areas east of the Rockies. Annually, hail losses reach more than 1 billion dollars. The IBHS has identified the factors that contribute to the extent of hailstorm damage, with the impact resistance of roofing materials being one of the most critical factors, along with hailstone size, density and hardness. Likewise, the roof is one of the components most vulnerable to hail. Analysis of property damage resulting from a hailstorm in Dallas-Fort Worth in 2011 found that roof losses accounted for 75 percent of property damage in the area, and more than 90 percent of damage payouts.

In their efforts to replicate the true nature of hail, the staff at IBHS has conducted extensive fieldwork, and travelled widely around the United States to gather actual hailstones immediately after a storm. Over the last five years, the IBHS hail team has collected more than 3,500 hailstones, focusing on their dimensions, mass and compressive stress. The stones range from .04 inches in diameter to well over four inches. In addition, IBHS has conducted three-D scans of more than one hundred stones to further educate themselves about the true nature of hailstones, and how they contribute to the overall damage inflicted by hailstorms.

The research findings of IBHS reinforce or complement those of ERA. IBHS has found that unsupported roofing materials perform poorly and ballasted low-slope roofs perform especially well in hailstorms because they disperse energy. IBHS recommends that builders use systems that have impact resistance approval, including their own fortified standard. While IBHS found that newer roofing membranes perform better than older membranes, ERA studies found that new, heat-aged and field-aged EPDM membranes all offered a high degree of hail resistance, demonstrating that EPDM retains the bulk of its impact resistance as it ages.

Both organizations stress that resilient roofing systems in new and retrofitted construction can make good financial sense. According to Julie Rochman of IBHS, “We are really going to continue focusing on moving our culture from one that is focused on post-disaster response and recovery to pre-disaster investment and loss-mitigation … we’re going to be very focused on getting the roofs right in this country.”

For the members of ERA, “getting the roof right” has long been a dominant focus of their businesses. Now, in the face of increasingly frequent and extreme weather events, getting the roof right means gathering up-to-the-minute research about resilient systems, and putting that research to work to create resilient roofs.

Definition of Resilience: Hospital Provides a Lesson in Preparing for Weather Events

Staten Island University Hospital escaped major damage during Hurricane Sandy. The city of New York allocated $28 million to fund the hospital’s resiliency plan, and the state contributed an additional $12 million.

Staten Island University Hospital escaped major damage during Hurricane Sandy. The city of New York allocated $28 million to fund the hospital’s resiliency plan, and the state contributed an additional $12 million.

Almost five years ago, Hurricane Sandy bore down on New York City with winds that reached gusts of 100 miles an hour and a storm surge 16 feet above normal that flooded huge parts of the city. Entire neighborhoods lost electricity for several days, the Stock Exchange closed during and immediately after the storm, and scuba divers were called in to assess damage in parts of the city’s submerged subway system.

Staten Island, one of New York’s five boroughs, was heavily damaged. Its position in New York Harbor, at the intersection of the coastlines of Long Island and New Jersey, leaves the island particularly exposed to storm surge during extreme weather events. A geologist from Woods Hole Oceanographic Institution in Massachusetts described Staten Island as being, “at the end of, basically, a big funnel between New Jersey and New York.”

Staten Island University Hospital almost miraculously escaped major damage, despite flood waters coming within inches of it doors. The hospital stayed open during and after Hurricane Sandy, continuing to provide vital services despite the storm. The hospital is home to the largest emergency room on Staten Island, and houses more than one third of the borough’s in-patient beds. New York Mayor DeBlasio has called the hospital, “a truly decisive healthcare facility—even more so in times of crisis.”

While both hospital and city officials were relieved that the facility had escaped Sandy largely unharmed, the lesson that Sandy delivered was taken to heart: major mitigation efforts were needed if the hospital expected to survive similar storms in the future. With this in mind, the city of New York allocated $28 million to fund the hospital’s resiliency plan, with the state kicking in an additional $12 million.

The money is being spent on three major projects to better prepare the hospital for future storms: the elevation of critical building power and mechanical systems, the installation of sanitary holding tanks and backflow prevention, and the installation of major wind resiliency and roofing improvements. 

Resilient Design

The Staten Island experience, and the plan to upgrade its ability to withstand major weather events, is hardly unique. Nationwide, resilient design has become a major focus of the construction community.

Hurricane Sandy certainly intensified the sense of urgency surrounding the need for resilience. But well before that, Hurricane Katrina, in 2005, provided a tragic case study on the fragility of seemingly stable structures, as the storm brought a small, poor southern city to the brink of chaos and devastated entire neighborhoods. While these two hurricanes drew national and international attention, communities throughout the country have also been dealing with frequent, erratic and intense weather events that disrupted daily life, resulting in economic losses and, all too often, the loss of human life. These emergencies may include catastrophic natural disasters, such as hurricanes, earthquakes, sinkholes, fires, floods, tornadoes, hailstorms, and volcanic activity. They also refer to man-made events such as acts of terrorism, release of radioactive materials or other toxic waste, wildfires and hazardous material spills.

The focus, to a certain degree, is on upgrading structures that have been damaged in natural disasters. But even more, architects and building owners are focusing on building resilience into the fabric of a structure to mitigate the impact of future devastating weather events. And, as with the Staten Island Hospital, the roof is getting new attention as an important component of a truly resilient structure.

The resilience of the roofing system is a critical component in helping a building withstand a storm and rebound quickly. In addition, a robust roofing system can help maintain a habitable temperature in a building in case of loss of power. Photo: Hutchinson Design Group.

The resilience of the roofing system is a critical component in helping a building withstand a storm and rebound quickly. In addition, a robust roofing system can help maintain a habitable temperature in a building in case of loss of power. Photo: Hutchinson Design Group.

So, what is resilience, how is it defined, and why is it important to buildings in differing climates facing unique weather events? The Department of Homeland Security defines resilience as “the ability to adapt to changing conditions and withstand and rapidly recover from disruption due to emergencies.” The key words here are “adapt” and “rapidly recover.” In other words, resilience is measured in a structure’s ability to quickly return to normal after a damaging event. And the resilience of the roofing system, an essential element in protecting the integrity of a building, is a critical component in rebounding quickly. In addition, a robust roofing system can provide a critical evacuation path in an emergency, and can help maintain a habitable temperature in a building in case of loss of power.

According to a Resilience Task Force convened by the EPDM Roofing Association (ERA), two factors determine the resiliency of a roofing system: durable components and a robust design. Durable components are characterized by:
Outstanding weathering characteristics in all climates (UV resistance, and the ability to withstand extreme heat and cold).

  • Ease of maintenance and repair.
  • Excellent impact resistance.
  • Ability to withstand moderate movement cycles without fatigue.
  • Good fire resistance (low combustibility) and basic chemical resistance.
  • A robust design that will enhance the resiliency of a roofing system should incorporate:

  • Redundancy in the form of a backup system and/or waterproofing layer.
  • The ability to resist extreme weather events, climate change or change in building use.
  • Excellent wind uplift resistance, but most importantly multiple cycling to the limits of its adhesion.
  • Easily repaired with common tools and readily accessible materials.
  • More Information on Resilient Roofing

    The Resilience Task Force, working with the ERA staff, is also responding to the heightened interest in and concern over the resilience of the built environment by launching EpdmTheResilientRoof.org. The new website adds context to the information about EPDM products by providing a clearinghouse of sources about resilience, as well as an up-to-date roster of recent articles, blog posts, statements of professional organizations and other pertinent information about resilience.

    “This new website takes our commitment to the construction industry and to our customers to a new level. Our mission is to provide up-to-date science-based information about our products. Resilience is an emerging need, and we want to be the go-to source for architects, specifiers, building owners and contractors who want to ensure that their construction can withstand extreme events,” said Mike DuCharme, Chairman of ERA.

    EPDM roofs can be easily repaired and restored without the use of sophisticated, complicated equipment. Photo: Hutchinson Design Group.

    EPDM roofs can be easily repaired and restored without the use of sophisticated, complicated equipment. Photo: Hutchinson Design Group.

    EPDM and Resiliency

    The Resilience Task Force also conducted extensive fact finding to itemize the specific attributes of EPDM membrane that make it a uniquely valuable component of a resilient of a roofing system:

  • EPDM is a thermoset material with an inherit ability to recover and return to its original shape and performance after a severe weather event.
  • EPDM has been used in numerous projects in various geographic areas from the hottest climate in the Middle East to the freezing temperatures in Antarctica and Siberia.
  • After decades of exposures to extreme environmental conditions, EPDM membrane continues to exhibit a great ability to retain the physical properties and performances of ASTM specification standards.
  • EPDM is the only commercially available membrane that performs in an unreinforced state, making it very forgiving to large amounts of movement without damage and potentially more cycles before fatiguing.
  • EPDM offers excellent impact resistance to hail, particularly when aged.
  • EPDM is resistant to extreme UV exposure and heat.
  • EPDM far exceeded the test protocol ASTM D573 which requires materials to pass four weeks at 240 degrees Fahrenheit. EPDM black or white membranes passed 68 weeks at these high temperatures.
  • Exposed EPDM roof systems have been in service now for 50-plus years with little or no surface degradation.
  • EPDM is versatile.
  • EPDM can be configured in many roofing assemblies, including below-grade and between-slab applications.
  • EPDM is compatible with a broad range of construction materials/interfaces/conditions, making it a good choice for areas that may encounter unique challenges.
  • EPDM can be exposed to moisture and intense sunlight or totally immersed in salty water.
  • EPDM can easily be installed, repaired and restored following simple procedures without the use of sophisticated, complicated equipment.
  • EPDM can be repaired during power outages.
  • For further information about the need for resilience, and the appropriate use of EPDM in resilient structures, visit EPDMTheResilientRoof.com.

    You Can Influence Codes and Standards

    As associate executive director of the Washington, D.C.-based EPDM Roofing Association (ERA), I focus a great deal of my time and energy on the codes and standards that regulate or guide the roofing business. In the current environment, driven by constant upgrades in technology, as well as the need to save energy, these codes—and the standards that often inform them—seem to be undergoing steady revision. Believe it or not—and the word “geek” does come to mind—I find participating in this process extremely interesting. In fact, following and sometimes influencing emerging codes and standards is among the most important responsibilities of my job.

    I’ll be the first to admit that a detailed review of a standards manual is probably not anyone’s idea of exciting reading. But given the importance of codes and standards to the construction industry, we ignore them at our own risk.

    For a start, what’s the difference between a code and a standard? Ask enough people in the roofing industry and you will get a variety of answers. But generally, codes are the “top-tier” documents, providing a set of rules that specify the minimum acceptable level of safety for manufactured, fabricated or constructed objects. They frequently have been enacted into local laws or ordinances and noncompliance can result in legal action. Standards, on the other hand, establish engineering or technical requirements for products, practices, methods or operations. They literally provide the nuts and bolts of meeting code requirements. If codes tell you what you have to do, standards tell you how to do it. Frequently, standards—especially “voluntary consensus standards”—are the precursors for what becomes law years down the road.

    ERA has represented the manufacturers of EPDM roofing for more than a decade. Through the years, we have learned the importance of interfacing with standard-setting and regulatory bodies. One of our first, and most important, learning experiences was working with the Northeast and mid-Atlantic states when they issued regulations designed to achieve federally mandated air-quality standards. (See the article in Roofing’s September/October 2014 issue, page 58.) The initial regulations, which lowered the amount of VOCs in many roofing products, were based on those used in southern California and incorporated provisions that were effective in the climactic and market conditions of that state. But states in the affected areas, from Virginia to Maine, confronted a situation where the new regulations threatened to bring the roofing industry to a sudden halt. In some instances, no adhesives and sealants were available to meet the new standards. And the new products, when they became available, would need to be effective in very cold climates totally unlike those on the West Coast.

    ERA worked with officials throughout the impacted areas, helping to create “phase-in” schedules that would give industry enough time to develop products to meet the new standards. In state after state, the local regulators welcomed our input. Our point-of-view was based on a deep understanding of the business needs of our industry. Just as important, we understood the science behind the proposed regulations and could work with the regulatory bodies to ensure the air-quality needs and the needs of the roofing industry were met.

    This experience has informed our ongoing approach to code-setting and regulatory bodies. Since our work with the states setting VOC standards, we have invested staff time and resources to stay current with and even ahead of proposals that would impact our members and their customers. We have testified before the South Coast Air Quality Management District in California on its proposal to limit VOCs. ERA has organized an ad-hoc coalition to successfully oppose an unnecessarily stringent proposal to require reflective roofs in the Denver area. And our organization is currently providing input to Atlanta-based ASHRAE’s efforts to clarify its regulation regarding air leakage. This issue—of great importance to the roofing industry—relates to other work being done in ASHRAE working groups and subcommittees on thermal bridging, as well as the definition of walls and wall assemblies. ASHRAE has convened an “Air Leakage Work Group” whose charge is to review the pertinent sections of Standard 90.1 and make recommendations for revising it. ERA staff will be present at this group’s meetings and will once again provide input based on the expertise of our members.

    When I work with code-setting and regulatory groups, I am reminded of that very familiar saying, “It’s not whether you win or lose, it’s how you play the game.” Based on our work at ERA, I’d like to revise that. Your skill at “playing the game” will definitely influence whether you win or lose. Our experience tells us that staying involved with regulatory groups and providing them with input based on firm science and field experience leads to a winning outcome for the roofing business.

    Black EPDM Roofing Helps Multifamily Buildings Achieve the Passive House Standard

    Two years ago, the three low-rise apartment buildings at the intersection of Southern Avenue and Benning Road in Washington, D.C., stood derelict and abandoned, uninhabitable reminders of 1960s brick and block construction. Today, the buildings—now known as Weinberg Commons—represent a landmark effort to provide clean, secure and energy-efficient shelter to low-income families. For the scores of people—architects, energy consultants, contractors and experts in housing finance, to name a few—who helped repurpose Weinberg Commons and bring it back to life, this project represents an unparalleled achievement in retrofitting. For the families who now live here, it means a giant step toward a more secure future.

    Thermal conductivity, air infiltration and exfiltration, and solar gain were important to the team working on Weinberg Commons

    Thermal conductivity, air infiltration and exfiltration, and solar gain were important to the team working on Weinberg Commons.

    One of the keys to that secure future will be very low or no energy bills. From the beginning, the team that oversaw the retrofitting of these buildings, each with almost 8,000 square feet of rentable space, was committed to ensuring that all three would show greatly reduced energy use and at least one would achieve Passive House (PH) certification.

    The criteria to become a passive structure are rigorous and focus on three specific design elements to reduce energy. (The requirements and certification observed by the Weinberg Commons team are set by Chicago-based PHIUS, the Passive House Institute U.S.)

    The first requirement is airtightness to ensure the building minimizes the amount of heated or cooled air it loses (0.6 air changes per hour at 50 Pascals of pressure).

    Second, a Passive House cannot use more than 4.75 kBtu per square foot per year. This is specific heating energy demand (or cooling in cooling climates).

    The third requirement caps the peak total amount of energy the heating and cooling system and appliances in the building can use per year, including domestic hot water, lighting and plug loads. It cannot exceed 38 kBtu per square foot per year.

    three low-rise apartment buildings at the intersection of Southern Avenue and Benning Road in Washington, D.C., stood derelict and abandoned, uninhabitable reminders of 1960s brick and block construction.

    Three low-rise apartment buildings at the intersection of Southern Avenue and Benning Road in Washington, D.C., stood derelict and abandoned, uninhabitable reminders of 1960s brick and block construction.

    Michael Hindle, a Baltimore-based Certified Passive House Consultant who is current president of the Passive House Alliance U.S. Board of Managers, helped with the retrofit design of Weinberg Commons. (Passive House Alliance U.S. is a PHIUS program designed to advance passive building.) He points out these three pass/fail criteria are measures of success, not design principles to help a team achieve the energy savings that lead to PH certification. However, Hindle highlights five design principles have been identified as important guides in the design of Passive House projects:

    • Continuous insulation through the building’s entire envelope without any thermal bridging.
    • An extremely tight building envelope, preventing infiltration of outside air and loss of conditioned air.
    • High-performance windows and doors, typically triple-paned.
    • Balanced heat- and moisture-recovery ventilation and a minimal space-conditioning system.
    • Solar gain is optimized to exploit the sun’s energy for heating purposes and minimize it in cooling seasons.

    Although only one building at Weinberg Commons has achieved PH certification, all three buildings were designed to the exact same specifications and technically could be PH certified as long as the rigorous airtightness threshold is met. Several factors influenced the decision, made at the outset of the project, to focus on just one building for PH certification. The design team’s perception was that airtightness would be the most challenging aspect for the contractor. Matt Fine, an architect with Zavos Architecture & Design, Frederick, Md., who led the project, explains: “The intention was to proceed with the first building, test its airtightness and improve on that scope of work for the next building. Repeat, refine and finally apply to the third sequential building.”

    Fine points out the first two buildings actually achieved “super” airtightness results relative to any new-construction project built today but did not cross the 0.6 air changes per hour at 50 Pascals of pressure threshold of Passive House. Given the budget-conscious nature of the Weinberg Commons project, resealing and retesting of the first two buildings was not an option for the team, but lessons learned from these two buildings were applied to the retrofit of the third building. “In retrospect, all three buildings would have been able to meet the PH threshold with relatively little extra effort,” Fine says. “But the dynamics of construction sequencing, along with imposed schedules for occupancy, complicated our ability to be flexible with scope change once the contracts were executed and limited dollars were allocated.”

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    Research Helps Industry Organizations Conclude Ballasted Roofs Provide Energy Savings

    During the last decade, the roofing industry has been increasingly impacted by two strong forces: first, rising energy prices with no real end in sight, and, second, increasingly stringent building codes and regulations, designed to limit emissions, reduce energy use and mitigate the impact of urban heat islands.

    The first definitive study to measure the energy-saving potential of ballasted roofs was done at Oak Ridge National Laboratory, Oak Ridge, Tenn., in 2007.

    The first definitive study to measure the energy-saving potential of ballasted roofs was done at Oak Ridge National Laboratory, Oak Ridge, Tenn., in 2007. PHOTO: EPDM Roofing Association

    The industry response has also been two-fold: In some instances, new products have been created, such as lower VOC adhesives, primers and sealants, self-adhering membranes and a wider variety of reflective membranes. At the same time, roofing professionals have taken a close look at some of the products that have been in use for a generation. Using rigorous science, they have tested these tried-and-true products to see how they measure up against the new standards. And in many cases, they’ve found that products that have been in use for decades are delivering great results in this new, energy-sensitive environment. Case in point: ballasted roofing, which has been available since the early 1970s, is turning out to be a great choice to meet 21st century needs.

    2007 Study

    The first definitive study to measure the energy-saving potential of ballasted roofs was done at Oak Ridge National Laboratory, Oak Ridge, Tenn., in 2007. Andre Desjarlais, ORNL’s group leader of Building Envelope Research, and his colleagues had just completed work in which “we had done a fairly substantial comparison of different cool roof technologies, both membrane types, as well as coatings,” Desjarlais says. At the request of EPDM manufacturers, working together at the newly founded EPDM Roofing Association (ERA), Bethesda, Md., as well as manufacturers within Waltham, Mass.-based SPRI, Desjarlais designed and implemented a second study to assess the performance of ballasted roofing. “We undertook a study to effectively expand what we had done earlier on coatings and membranes,” he says.

    Other factors also encouraged ORNL to generate data about ballasted roofing. The California Energy Commission, Sacramento, had just revised its codes, essentially defining roofs with high reflectance and high emittance as the only choice of roofing membranes that would deliver high energy savings. Desjarlais believed this definition of a “cool roof” might be inaccurately limiting roofing choice by excluding other roofing materials, such as ballasted roofs, that would deliver comparable savings.

    The California Energy Commission, Sacramento, had just revised its codes, essentially defining roofs with high reflectance and high emittance as the only choice of roofing membranes that would deliver high energy savings.

    The California Energy Commission, Sacramento, had just revised its codes, essentially defining roofs with high reflectance and high emittance as the only choice of roofing membranes that would deliver high energy savings. PHOTO: EPDM Roofing Association

    In addition, in Chicago, a new Chicago Energy Code was adopted as early as 2001 “with high reflectivity and emissivity requirements that limited severely building owners’ and managers’ roof system choices”, according to a paper presented in 2011 by Bill McHugh of the Chicago Roofing Contractors Association. At the roofing industry’s request, a reprieve was granted, giving the industry until 2009 to come up with products with a reflectivity of 0.25.

    Faced with that 2009 deadline, the Chicagoland Roofing Council, Chicago Roofing Contractors Association and Rosemont, Ill.-based National Roofing Contractors Association began in 2001 to conduct research on products that would help to meet the city’s goal of creating a workable Urban Heat Island Effect Ordinance while giving building owners a wider choice of roofing products. As part of their effort, the industry coalition turned its attention to the energy-saving qualities of ballasted roofing and coordinated its work with the research at ORNL.

    Desjarlais points out the concept of thermal mass having energy benefits has been accepted for years and has been a part of the early version of ASHRAE 90.1. “Thermally massive walls have a lower insulation requirement, so there was industry acceptance of the fact that using mass is a way of saving energy,” he says. “But we had a hard time translating that understanding from a wall to a roof. Whether you do that with a concrete block or a bunch of rocks doesn’t really matter. The metric is no different. Roofs or walls.”

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    An ERA Study Proves EPDM Easily Lasts More than 30 Years

    More and more building owners are seeing the light: Roof systems based on historical in situ performance for more than 30 years are the best roof system choice to benefit the environment. EPDM roof membrane has been utilized as a roof cover for more than 40 years, and there are numerous examples of ballasted roofs greater than 30-years old still performing. New seaming technologies, thicker membrane and enhanced design are creating roof systems with projected 50-year service lives. EPDM roof covers’ physical characteristics have changed little in 30 years, and because potential for 50-year-plus service life is possible, they are a solid choice of design professionals, building owners and school district representatives who truly desire a roof system that benefits the environment.

    PHOTO 1: This ballasted 45-mil EPDM roof system has been in service for 32 years.

    PHOTO 1: This ballasted 45-mil EPDM roof system has been in service for 32
    years.

    In 2010, the Washington, D.C.-based EPDM Roofing Association (ERA) was determined to answer the question: “How long can an EPDM roof perform?” Consequently, roof membrane samples from five roof systems with a minimum age of 30 years were obtained for testing of their physical properties. The physical and mechanical properties evaluated (using relevant ASTM standards) were overall thickness, tear resistance, tensile set, tensile strength and elongation, and water absorption. The results were positive, showing that even after 30 years of infield exposure nearly all the physical characteristics of EPDM membrane meet or exceed ASTM minimums. But the question of how long EPDM roofs could last remained. Thus, a second phase of testing was undertaken.

    These properties were studied for “as received” and “after heat-conditioning” for up to 1,500 hours at 240 F. Results showing how these membranes performed before and after heat-conditioning are presented with the intent of defining characteristics for long-term service life of roof membranes.

    TESTING PHASE ONE

    Ethylene-propylene-diene terpolymer (EPDM) has been used in waterproofing and roof applications for more than 45 years in North America. Introduced into the roofing market in the 1960s, EPDM grew, especially after the 1970s oil embargo, to be a roofing membrane choice for new construction and roofing replacement projects. EPDM has achieved long-term in situ performance in part because of its chemical structure, mostly carbon black, which resists ozone and material decomposition, as well as degradation caused by UV light, which is the No. 1 degradation element to roofing materials exposed to the sun (see photo 1). The carbon black also provides reinforcement, yielding improved physical and mechanical properties.

    Long-term performance of roof-cover material is dependent upon its resistance to the combined effects of ponding water, UV radiation, ozone, heat and thermal cycling. Geographical location can exacerbate or reduce the impact of climatic factors. In ballasted systems, the ballast acts to provide protection from the UV rays and minimizes the effect of climatic influences.

    ERA’s study had three specific goals:

      1. Verify the long-term performance characteristics of EPDM membranes over 30 years. (At the time of the study, the only in situ membranes that were around for 30 years were 45-mil EPDM membranes. Currently 60- and 90-mil are the standard choices. It is assumed that results for the 45-mil material can be prorated for the thicker membrane.)

      2. Scientifically validate the empirical sustainability experiences.

      PHOTO 2: This recently installed, ballasted, 90-mil EPDM roof was designed for a 50-year service life.

      PHOTO 2: This recently installed, ballasted, 90-mil EPDM roof was designed for a 50-year service life.

      3. Create a foundation for specifier-to-owner discussions in regard to long-term service life. Five roofs, four ballasted and one fully adhered, with in situ service lives approaching or over 30 years were identified and samples were taken. All roofs were fully performing without moisture intrusion.

    The samples were sent for testing per ASTM D4637 for:

    • Elongation
    • Tensile strength
    • Thickness
    • Factory seam strength (psi)

    PHOTOS: HUTCHINSON DESIGN GROUP LTD.

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    ARMA, ERA and PIMA Research Advanced Roof Systems in Northern Climates

    A coalition of trade groups is funding a research project about advanced roofing systems that were installed on an upstate New York correctional facility to evaluate the benefits of thermal insulation and cool roofing in Northern climates.

    The Asphalt Roofing Manufacturers Association (ARMA), Washington, D.C.; EPDM Roofing Association (ERA), Washington; and the Polyisocyanurate Insulation Manufacturers Association (PIMA), Bethesda, Md., are sponsoring continued analysis of a reroofing project at the Onondaga County Correctional Facility, Jamesville, N.Y. The Onondaga County Department of Facilities Management identified a need to study building energy use and stormwater runoff from roof systems. Temperature and rain data from the project, which includes vegetative roofing, increased insulation levels and “cool” roofs, will provide information about building performance and roof covering selection.

    “ARMA members promote a balanced approach to roofing performance, especially when it comes to saving building energy,” says Reed Hitchcock, ARMA’s executive vice president. “Using a whole-building approach, where roofing reflectivity, insulation levels and other design elements are considered in the decision-making process, will help ensure the right system is selected; this project can only help with that decision.”

    When the correctional facility was due for a major reroofing project in 2009, Onondaga County saw a unique opportunity to evaluate the water-retention and energy-efficiency performance for a variety of different roof covering assemblies. The project also offered valuable information that could be used to identify the best options for future reroof projects across the county’s entire building inventory.

    The county worked with Ashley-McGraw Architects, Syracuse, N.Y., and CDH Energy, Cazenovia, N.Y., to design and install a field monitoring system to collect data on thermal performance, weather conditions and roof runoff from four buildings at the Jamesville facility. CDH Energy released a report in October 2011 that made recommendations on roof covering selection.

    Hugh Henderson, P.E., CDH Energy, remarked the original report laid the groundwork for future roofing projects in Onondaga County. “The use of vegetative roof systems as a stormwater control mechanism was the most important takeaway from the first years of the project,” he explains. “Continuing the project will provide a better evaluation of cool roof and insulation products as part of roof designs in colder climates.”

    With the instrumentation still in place, it was a simple decision to continue evaluating the roof coverings over a longer time period to better see how roof coverings interact with weather conditions. Of particular interest is the effect of accumulated snow on roofs that may affect the buildings’ thermal performance.

    “Roof insulation is an integral part of the design strategy for a building’s energy-efficiency footprint, and this study will help building owners, contractors and architects assess a roof’s performance from a broader basis and ensure the best energy efficient components are used,” adds Jared Blum, PIMA president.

    The Onondaga County reroofing project includes an analysis of the comparison of cool roof technologies, consisting of reflective roof surfaces and high-performing well-insulated roof covering assemblies. “Our members produce reflective and absorptive roof coverings; this study will provide meaningful data that can help designers select the right products for their particular project, regardless of where in the country the roof will be installed,” notes Ellen Thorp, ERA’s associate executive director.

    The project is expected to run through 2015.

    USGBC and other Code-, Regulation- and Guideline-setting Bodies Are Increasingly Working with Industry

    Earlier this year, the USGBC announced a 16-month extension to register products under LEED 2009, prior to the implementation of LEED v4 on Oct. 31, 2016. The action set off speculation, both off and online, about what caused USGBC to act with some calling for a more in-depth explanation for the delay. But the real reason, most likely, was simply stated in USGBC’s own press release: In a survey taken at GreenBuild in late October, 61 percent of respondents—almost two-thirds of those polled—said they are “not ready” or “unsure” if they were ready to pursue LEED v4 and required additional time to prepare. USGBC said it was also getting the same message from the international community.

    The response to the USGBC action tended to fall into two camps: those who said the council was caving to the pressure of industry and those who said USGBC was taking a reasonable action after having put forward a complicated, unworkable and unneeded ratings system. Based on my extensive work with code-setting and regulatory bodies, I see a third option emerging, one that bodes well for the environment and the building sector.

    During the past year, as part of my job as associate executive director of the EPDM Roofing Association (ERA), I have attended and testified at more than 20 hearings held by a broad range of groups, including the IGCC, SCAQMD (the South Coast Air Quality Management District, overseeing much of Southern California) and ASHRAE. Frequently, I have been accompanied by representatives of our member companies, Firestone, Carlisle and Johns Manville. And often I have been joined by members of industry groups, such as the American High-Performance Buildings Coalition.

    Collectively, we have offered our findings on a range of issues that are critical to our industry, such as the importance of climate in the choice of roofing color and the need to preserve the builder’s choice when deciding on reflectivity options and the unique qualities of ballasted roofing that should be considered in any code-setting activities. Our testimony is based on meticulous research, as well as on empirical evidence and firsthand knowledge gained from years of experience in the building industry. Increasingly, we find that we are listened to and that our interaction with code-setting and regulatory bodies is a mutually beneficial exchange of ideas, rather than an adversarial give-and-take.

    For instance, we worked closely with the Ozone Transport Commission in its efforts to achieve federally mandated clean air standards in the Northeast and Mid-Atlantic states. Initially, we pointed out that their proposed regulations would have mandated the use of low-VOC products that were in development but not yet available in the marketplace. And we also demonstrated that the roofing industry would need ample time to train roofing contractors in the use of these new products. We worked with regulators, state by state, and developed a mutually agreed upon seasonal approach. While the process is still ongoing, many state regulators expressed their gratitude for the advice we offered and the expertise we brought to the table.

    I am certainly not privy to the inner workings of the USGBC. But their extension of the deadline for the implementation of LEED v4 seems to be part of a trend: The groups who are drawing up codes, regulations, and ratings systems are increasingly working with the building industry and the end results are based on good science and good sense.

    New VOC Regulations Threatened the Quality of Roofing Assemblies until the Roofing Industry Became Involved

    Ellen Thorp, associate executive director of the EPDM Roofing Association, makes it a point to be responsive to the many inquiries she gets. Most deal with routine requests for information about EPDM, but one phone call Thorp fielded six years ago from one of ERA’s member companies stood out from the rest. Ultimately, it changed the way ERA and the roofing industry do business.

    A manufacturer’s rep had heard from a customer in Connecticut that the state was about to implement VOC regulations. The problem: The new regulations would ban some of the adhesives, sealants, and primers essential to installing EPDM and other roofing products, and there were no substitute products available to meet the new standards. If the new regulations went into effect as scheduled, they threatened to negatively impact the safety and quality of roofing assemblies in the affected area and the roofing industry as a whole.

    The proposed regulations were part of an effort by the Ozone Transport Commission, or OTC, to achieve federally mandated air-quality standards in the Northeast and Mid-Atlantic. The OTC was created under the Clean Air Act to develop solutions for the New England states, as well as Delaware; Maryland; New Jersey; New York; Pennsylvania; Virginia; and Washington, D.C. At the time of OTC’s creation, most of these states had not attained federally mandated ozone standards, and the region lagged behind other parts of the U.S. in achieving compliance.

    As part of its initial work, OTC developed a Model Rule for Adhesives and Sealants, based on regulations used in California, incorporating provisions effective in the climactic and market conditions of that state. At the time of the phone call to Thorp, the OTC had released the model rule, and states were beginning to draft their own regulations that included implementation dates within the next year. “The VOC limits the OTC was proposing would have required products that did not exist in the Northeast and Mid-Atlantic,” Thorp explains. “It was also concerning that they were basing the limits on California regulations. The climate in the Northeast is very different than in California, so we didn’t feel it was good science to be creating a model rule based on a place that had a completely different climate.”

    Thorp and the ERA member companies were very interested in working with state regulators. “It certainly is our priority to reduce VOC emissions wherever possible, but it also is important to us to have regulations that our industry could work with and are based on the best available science,” she says. In fact, products that would meet the new regulations were in development but were not yet available. In addition, the new adhesives and sealants would require new or modified application techniques. That meant the roofing industry needed time to train thousands of roofing contractors.

    ERA’s first step was to support its assertion that the climate of the Northeast differed dramatically from that of California. ERA hired Jim Hoff of Tegnos Research Inc. to review weather data and the effects the weather has on low-VOC products. “At ERA’s expense, we assembled relevant scientific data and provided it to the state regulators,” Thorp adds.

    ERA worked with regulators in each state, sharing the results of its research. ERA provided the state environmental protection and air quality bureaus with detailed information about what sealants were available and explained the time needed to train roofing contractors. Working together, the regulatory bodies and ERA were able to agree on a phased-in or seasonal approach. For instance, in a majority of the states, the new low-VOC products were required initially only in the summer for three months. The year after, they were required for five months. Then, the following year, they were required year-round. Once these states had found success with this approach, others followed suit. “We explained to the regulators the importance of being consistent since many roofing companies do work across multiple states, especially in the Northeast where the states are small and roofing companies are likely to work across state lines,” Thorp notes.

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