Author Archives: CS Editor

Grocery stores and Green Globes

Many supermarkets, including Whole Foods, are being certified under the Green Globes rating program. Photo © Alistair Tutton

Many supermarkets, including Whole Foods, are being certified under the Green Globes rating program. Photo © Alistair Tutton

The Green Building Initiative (GBI) announced there was a wave of certifications for new grocery stores under its Green Globes rating program in July.

The properties include Whole Foods, Price Choppers, Aldi’s, Harris Teeter, Wegmans, and Publix stores across the country, along with New Seasons Markets in Oregon.

New Seasons director of construction and facilities, Wayne Pipes, said Green Globes certification helps validate the company’s sustainability story.

“We were the first B-Corp grocer in the world—sustainability is part of our DNA,” he explained. “We’re classified a zero-waste company, and using less energy is part of who we are. Green Globes help make our mission clear throughout the community at large as we continue to grow.”

According to GBI president Jerry Yudelson, there are numerous advantages for grocery stores to pursue Green Globes as a rating program.

“Grocers’ need for refrigeration make energy-efficient construction and operations especially critical, both from an environmental and an economic standpoint,” he said. “Green Globes is ideal for retail environments because of its integration with the Energy Star program—which includes supermarkets as a building occupancy category—and because it accommodates different building scenarios by not applying penalties for features that aren’t applicable.”

To date, nearly 50 Whole Foods stores have either been certified to Green Globes, or are now in the process. Last year, the chain also began taking its first existing building through the rating program—a Portland, Oregon, facility that earned a Three Green Globes Rating—explained Pacific Northwest Region construction manager Bob Gordon.

“If you’re looking for ways to reduce your building footprint or wondering where your facility stands on the green spectrum, this process has a lot of merit,” he said. “The comprehensive evaluation looked at both how the building was built and is operated. It will help us piece together a preventative maintenance program for the whole region.”

The Green Globes certification process also incorporates the U.S. Environmental Protection Agency’s (EPA’s) GreenChill Store Certification Program for Food Retailers, which recognizes individual stores for using commercial refrigeration systems with reduced environmental impact. (Stores also can achieve certification under GreenChill itself.)

TPO on Top: Why the Roofing Material Continues to Shine

by Mike Mendoza

Thermoplastic polyolefin (TPO) is a relatively new material, but makes up one of the fastest-growing sectors of the commercial roofing industry.  All images courtesy Firestone Building Products

Thermoplastic polyolefin (TPO) is a relatively new material, but makes up one of the fastest-growing sectors of the commercial roofing industry. All images courtesy Firestone Building Products

As building codes and environmental trends continue to evolve, so too does the diversity of roofing material options. These factors, along with others, make construction specifiers’ roofing installation and selection prowess of utmost importance.

Among the available choices is thermoplastic polyolefin (TPO). Despite the fact this technology is fairly new in the scheme of roof materials, it makes up one of the fastest-growing sectors of the commercial roofing industry. That growth brings with it constant improvements to the chemical composition of the membrane to achieve greater durability and longevity.

Nevertheless, representatives for the Single Ply Roofing Industry (SPRI) still point to early 1990s TPO installations that continue to perform thanks to proper installation and maintenance. SPRI data indicates about 371.6 million m2 (4 billion sf) of TPO was installed in North America between 2005 and 2010, with nearly the entirety still performing without issue.1

“We at SPRI are confident TPO roofing systems will continue to provide quality and value for many years to come,” said the association’s technical director, Mike Ennis.

Indeed, a 2013 study that used ASTM D6878, Standard Specification for Thermoplastic Polyolefin-based Sheet Roofing (revised to address concerns of prolonged exposure in extreme heat climates) shows the material’s durability.2

“The heat aging exposure at (116 C [240 F]) was extended from 670 hours to 5400 hours (32 weeks),” the study states. “To meet these new requirements, it is critical for TPO roofing formulations to contain high-quality resins combined with tailored stabilization, flame retardants, and membrane design.”

Results showed TPO roofing membranes produced using the right polymer formation and stabilization can perform in some of the most extreme climate conditions: “Depending on the climate zone, 1.5-mm (60-mil) membranes may last up to 25 years or more.”

Beyond durability, TPO single-ply roofing membranes offer several other performance and installation advantages. These assemblies can provide resistance to ultraviolet (UV) rays, ozone, and chemical exposure. Further, the reflective surface meets the U.S. Environmental Protection Agency’s (EPA’s) Energy Star requirements, and is both recyclable and composed of recycled content.

Knowing the options
Settling on the ideal TPO roofing system relies on identifying and analyzing the characteristics surrounding climate and condition of a commercial building’s existing roof surface. Factors include:
● potential for tears and abrasions;
● area wind speeds;
● UV exposure; and
● various surfaces (e.g. vertical parapet walls) and slopes.

When it comes to color choice, white is among the most popular option for reasons discussed later in this article. However, it is not the sole TPO variety to consider, particularly if another hue better suits a rooftop. In addition to white, TPO membranes often come in gray and tan.

Since TPO membranes are installed fully-adhered, ballasted, or mechanically fastened, they work with a range of building envelope designs, offering architects flexibility. Architects most commonly select TPO roofing for flat or low-slope installations because of its cost-effectiveness, easy installation, and heat-welded seams that prevent moisture penetration.

Keeping cool
A specific driving factor for choosing TPO is within the realm of cool roofing. The Cool Roof Rating Council (CRRC) was created in 1998 to “develop accurate and credible methods for evaluating and labeling the solar reflectance and thermal emittance of roofing products,” according to the nonprofit organizatioRoof Surface Properties (CRRC)n’s history and bylaws. In the 15 years or so since, a lot of roofing products now come in what can be considered ‘cool’ varieties.3 Field-applied coatings, single-plies, tiles, and others fit this bill, which the council defines as a surface that reflects and emits the sun’s heat back into the sky rather than transferring it to a building.

A roof’s solar reflectivity and thermal emittance (the ability to release absorbed heat), are both measurable factors, according to the U.S. Green Building Council (USGBC). The Green Building Alliance, a chapter serving the Greater Pittsburgh, Laurel Highlands, and Northwest Pennsylvania branches, says as many as 90 percent of roofs in the United States are, “poorly designed and built with dark, non-reflective heat-absorbing materials,” causing rooftop temperatures to hover as many as 50 C (90 F) above that of the air.

The more reflective a TPO surface, the more likely it will comply with increasingly stringent building codes. Therefore, white TPO membranes—the most reflective—can be a suitable choice for those striving for maximum energy savings and environmental benefits.

The U.S. Department of Energy (DOE) touches on this concept in its 2010 study entitled, “Guidelines for Selecting Cool Roofs,” stating a conventional dark-colored surface reflects about 20 percent of incoming sunlight while a “cool” light-colored one (white being the lightest) reflects as much as 80 percent.4

EPA goes one step further in its “Reducing Urban Heat Islands: Compendium of Strategies” focusing on cool roofs. The report uses a diagram from the Lawrence Berkeley National Laboratory (LBNL) to compare the solar reflectance of black, metal, and white roofs.5

Roof Reflectance, EmittanceOn a hot, sunny summer day, a black roof that reflects five percent of the sun’s energy and emits more than 90 percent of the heat it absorbs can reach 82 C (180 F). A metal roof will reflect most of the sun’s energy while releasing about a fourth of the heat it absorbs; it can warm to 70 C (160 F). A cool roof will reflect and emit the majority of the sun’s energy and reach a peak temperature of 48 C (120 F).

CRRC lists white, tan, and gray TPO roofs among its ‘environmentally friendly’ options, and white and tan are compliant with California’s Title 24 Energy Efficiency Building Standards. Cool roof requirements have been adopted in several U.S. building energy codes, and an increasing percentage of electric utilities have begun offering rebates for cool roofing materials, including TPO, that help conserve energy and reduce buildings’ environmental impacts.

According to USGBC, TPO and other cool roof options yield the following benefits:
● utility rebate opportunities;
● lower indoor temperatures;
● reduced maintenance costs (partially due to the material’s longer lifespans);
● improved air quality resulting from a reduction of emissions such as mono-nitrogen oxides and carbon dioxides in the atmosphere;
● mitigated heat island indexes (i.e. less heat creation in dense, urban areas); and
● reduced energy bills because less air-conditioning is needed during the summer.

Conclusion
Not unlike other roofing product manufacturers, those offering TPO will recommend consulting a design professional to ensure proper roofing system selection, conformance to building codes, and insurance requirements. Such customizations further emphasize evaluating a roof’s current condition is paramount when determining how best to repair or replace it. Further with ever-changing code and material options available, it is important for construction professionals to remain educated about the changing commercial building products landscape.

Of course, amidst the increasingly popular cool roofing and TPO possibilities, it is crucial to be cognizant of the fact roofing materials are not the sole remedy to increase overall building performance. It takes a holistic approach to have a building perform at peak efficiency.

This fact emphasizes the importance of building products manufacturers working closely with architects and construction specifiers—as well as consultants, contractors, facility operators, and building owners—who share similar goals of increasing overall building performance.

Together, these professionals should consider the entire building envelope to continue revolutionizing the commercial building industry, yielding an impact that reaches far beyond their individual buildings, cities, and immediate populations.

Notes
1 Visit www.spri.org/pdf/spri_responds_to_pro_roofing_article_on_tpo.pdf. (back to article)
2 Visit msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_08e0/0901b803808e057f.pdf. (back to article)
3 See the council’s “Reducing Urban Heat Islands: Compendium of Strategies” by visiting www.epa.gov/hiri/resources/pdf/CoolRoofsCompendium.pdf. (back to article)
4 The DOE study can be found at www1.eere.energy.gov/femp/pdfs/coolroofguide.pdf. (back to article)
5 See S.L. Konopacki et al’s 1998 report, “Demonstration of Energy Savings of Cool Roofs,” also known as LBNL-40673. (back to article)

Mike MendozaMike Mendoza is the thermoplastic polyolefin (TPO) product manager for Firestone Building Products. He is responsible for researching market trends and directing the planning and development of thermoplastic products. Mendoza previously spent 13 years at Owens Corning where he served in various roles including as a southwest region sales manager for roofing, strategic product planning manager for asphalt, and director of global sourcing for insulation. He can be reached at mendozamichael@fsdp.com.

BHMA: Continent’s first PCRs for architectural hardware

Product category rules (PCRs) for door hardware have been created to assist manufacturers in writing environmental product declarations (EPDs). Photo © BigStockPhoto/KTS Design

Product category rules (PCRs) for door hardware have been created to assist manufacturers in writing environmental product declarations (EPDs). Photo © BigStockPhoto/KTS Design

The Builders Hardware Manufacturers Association (BHMA) has published product category rules (PCRs) for locks, latches, exit devices, door closers, and hinges. This sets the framework for manufacturers to develop environmental product declarations (EPDs), ultimately increasing transparency and helping design professionals compare components.

PCRs identify the rules and requirements for lifecycle assessments (LCAs), and are important for EPDs under International Organization for Standardization (ISO) 14025, Environmental Labels and Declarations: Type III Environmental Declarations−Principles and Procedures.

BHMA initiated development of its PCR with Underwriters Laboratories’ (UL’s) expertise in the field of environmental impacts. After several months of development, the PCR was posted for review on the UL Environment and GEDnet websites as part of an open consultation period. The full, revised document is now available for download in the group’s new sustainability subsite, along with helpful definitions of basic terminology.

“Responding to a need for uniform requirements, BHMA also ensured international PCR documents stand in alignment with ours,” explained the association’s executive director, Ralph Vasami. “These product category rules are the first industry-wide resource for hardware, and demonstrate our industry’s commitment to constructing more environmentally conscious buildings in North America.”

“The PCR creates foundational rules for conducting a lifecycle assessment and identifying potential environmental impact via EPD,” he told The Construction Specifier. “EPDs are being increasingly requested in model and state building codes as evidence of a product’s environmental impact due to these declarations’ broader assessment capability.”

Building Knowledge to Improve Project Delivery

Joy_Davis_2652_BESTINSIDE CSI
Joy Davis, CSI, CCPR

CSI is the only organization exploring the in-between places in construction: how the teams work together, what the documents, drawings, and models mean to each of them, and where the potentially disastrous conflicts are hiding, waiting to delay a project and increase its cost.

The institute will continue to provide inspiring programming to help you navigate these areas this year. Next month, there is CONSTRUCT 2014 & the CSI Annual Convention in Baltimore, along with the CSI Academies in San Francisco, next April. As well, there are the fall and spring certification exams, along with free monthly practice group meetings and webinars. However, there is other notable programming planned for the next 12 months.

Young professionals
Knowledge drain, emerging technologies, and global competition—the changing construction industry has created a unique set of challenges for the next generation of industry professionals. CSI is launching a new series of free webinars to expose participants to aspects of the project delivery cycle they may not otherwise have encountered: the team members, their responsibilities, and how they effectively communicate to get a job done on time and on budget. This curriculum is focused on creating a foundation for successful workforce collaboration.

Young professionals have an important voice, and CSI is ready to help them become leaders and change agents within their firms, and within the industry.

Trusted advisors, not salesmen
The success of product representatives is dictated by what they know, who they know, and personal ethics and integrity. CSI will continue offering programming this year that supports representatives, helping them become trusted advisors. Look for the monthly Product Representative Bulletin, which announces upcoming education for product representatives, including free webinars. CSI is now surveying product representatives to determine what programs to provide in these webinars, as well as at events such as the Product Representatives Academy.

CSI is also developing a new workshop focused on guide specifications, how to construct them, and how to use them. Look for more information about this event in the spring.

Changing role of specifiers
Specifications and the specifier’s role have long been a cornerstone of the construction industry. Coordinating information and sourcing products that fit the needs of a project is an integral part of every project, but how this work is done is changing.

CSI holds monthly Specifying Practice Group webinars geared toward discussing the future of the construction industry and, more specifically, how the role of the specifier may evolve. It also offers the Construction Specifier Academy, and is planning a new workshop focused on helping specifiers envision their futures in the industry.

Contract administration
Without the contract documents, construction does not happen. With monthly webinar discussion points based around the Construction Contract Administration Practice Guide, the Construction Administration Practice Group discusses the real issues facing contract administrators. These topics will also be explored in the Construction Contract Administrator Academy, as well as at CSI’s Real World Application Workshop (November 14, Charlotte, North Carolina), at which participants will learn to recognize critical decision points in the project delivery process and contract administration that can determine potential successes, or crises.

In the loop
To receive notification about these events and webinars, e-mail marketing@csinet.org and ask to be added to the ‘young professionals,’ ‘product representative,’ ‘specifier,’ and/or ‘contract administrator’ contact lists.

Invest in yourself by participating in CSI’s programming this year. Make sure your contact information is up-to-date at www.csinet.org/mycsi to be certain you do not miss a free webinar that could change your perspective.

WRB: Water (or Weather?)-resistive Barrier

slaton patterson sutterlinFAILURES
Deborah Slaton, David S. Patterson, AIA, and Jeffrey N. Sutterlin, PE

Using the acronym ‘WRB’ is common, but the intended meaning is often misunderstood, as it can refer to either a ‘water’ or ‘weather’-resistive barrier, with the two having different performance expectations.

The 2012 International Building Code (IBC), Section 1403.2−Weather Protection requires exterior walls “provide a building with a weather-resistant exterior wall envelope…designed and constructed… to prevent the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior veneer.” Water-resistive barriers are defined in Section 1404.2 as “a minimum of one layer of No. 15 asphalt felt, complying with ASTM D226, Standard Specification for Asphalt-saturated Organic Felt Used in Roofing and Waterproofing, for Type 1 felt or other approved materials…to provide a continuous water-resistive barrier behind the exterior wall veneer.”

For adhered stone veneers, Section 1405.10.1.1 requires water-resistive barriers to be installed per section 2510.6, which in turn directs the reader back to Section 1404.2, but adds the requirement the water-resistive barrier be vapor-permeable with the equivalent performance of two layers of Grade D paper when applied over wood-based sheathing. (Section 2510.6 of the 2015 IBC has been revised to require a vapor-permeable barrier with performance at least equivalent to two layers of a water-resistive barrier complying with Type I of ASTM E2556, Standard Specification for Vapor Permeable Flexible Sheet Water-resistive Barriers Intended for Mechanical Attachment, which includes polymer-based barriers.) It should be noted IBC’s Chapter 14−Exterior Walls does not reference weather-resistive barriers.

The American Architectural Manufacturers Association (AAMA) defines weather-resistant (not ‘resistive’) barriers as a surface or a wall responsible for preventing air and water infiltration to the building interior. Manufacturers of polymer-based barriers (i.e. building wraps) also distinguish between water-resistive and weather-resistive barriers, with the latter providing the added benefit of also serving as an air barrier for the vertical building enclosure.

While not as potentially destructive as bulk water leakage, moisture transport via air infiltration can contribute to moisture-related problems in the building enclosure. Weather-resistive barriers are often more robust as compared to water-resistive barriers and require taping of all laps and terminations to resist not only water penetration, but also air infiltration.

Code-mandated water-resistive barriers are typically limited to residential and low-rise structures, while weather-resistive barriers are commonly specified for commercial buildings or projects where a higher level of performance is desired of the vertical building enclosure and control of interior environmental conditions is critical.

It is important the design professional and installer understand the intended purpose of the specified WRB—to resist water or to resist air and water—as the installation varies between the two types of barriers. However, regardless of whether the WRB is intended to function as a water- or weather-resistive barrier, the WRB must be properly installed so as to maintain continuity of the barrier. This requires the WRB to be properly integrated with flashings, wall openings, and all adjacent enclosure assemblies, and to be sufficiently overlapped, correctly shingled, and properly sealed or taped at exposed laps (horizontal and/or vertical, depending on its intended purpose), as barrier discontinuities result in potential entry points for water (and air) to migrate into the building.

The opinions expressed in Failures are based on the authors’ experiences and do not necessarily reflect those of the CSI or The Construction Specifier.

Deborah Slaton is an architectural conservator and principal with Wiss, Janney, Elstner Associates, Inc. (WJE) in Northbrook, Illinois, specializing in historic preservation and materials conservation. She can be reached at dslaton@wje.com.
David S. Patterson, AIA, is an architect and senior principal with WJE’s Princeton, New Jersey, office, specializing in investigation and repair of the building envelope. He can be e-mailed at dpatterson@wje.com.
Jeffrey N. Sutterlin is an architectural engineer and senior associate with WJE’s Princeton office, specializing in investigation and repair of the building envelope. He can be contacted via e-mail at jsutterlin@wje.com.