When the Baystate Medical Center in Springfield, Mass., began the new construction on a massive, four-phased project, a green roof was to be an invaluable addition to several new structures. The project, located at the Chestnut Street campus, is part of an ongoing vision of the hospital’s master plan, which encompasses 640,000 square feet (59,458 m²) of construction and is currently being budgeted at $296 million.
Titan Roofing, Inc.’s role consisted of two new seven-story patient towers and a five-story pediatrics wing as well as a new main entrance to the facility.
Like many organizations seeking to blend form, function, and sustainability, Baystate focused on green solutions, ultimately selecting Titan Roofing for the job. Not only was Titan a well-established company in the Northeast, but their expertise with green roofing and a long-term relationship with Kemper products made for an ideal match between the client and Steffian Bradley Architects of Boston, Mass. This led to the least disruptive application process and allowed the most benefits to the patients themselves.
Brian McKernan, project manager for Titan’s Chicopee, Mass. office, oversaw a crew of between 6 and 10 at the Baystate jobsite. Ultimately, the contract was valued at $3.3 million, spanned nearly two years — from the spring of 2010 to the fall of 2011 — and included 71,000 square feet (6,596 m²) of Firestone polyvinyl chloride (PVC) roofing membrane, 26,000 square feet (2,416 m²) of EcoStar slate, and 28,100 square feet (2,611 m²) of Kemper System America’s membrane.
New England Weather
Typically the team started with new construction and a new, poured concrete slab, and then they provided additional prep-work as needed prior to installation. “The decks were ready for waterproofing in the late fall of 2010,” explained McKernan. “The cold winter weather was approaching, so we repaired any cracks in the concrete deck surface with a repair mortar mixture of Kemperol Primer and sand.” All vertical wall transitions and any penetrations were also temporarily sealed with the same mixture. McKernan added, “We ended up waiting until spring to begin our waterproofing work while relying on the concrete deck to keep the space below it dry.”
The Kemperol 2K-PUR membrane system was utilized because of the lack of odor during installation. As McKernan explained, “The adjacent buildings were occupied by many of the subcontractor’s and hospital’s personnel during the install, so we had to be conscious of any odor or hazards that would hamper the existing operations at the hospital.” One of the difficulties encountered was finding that “the high building walls adjacent to the Kemper work area blocked a good portion of the air flow.” And, as a result, “the fumes lingered in the area at times, so we had to set up large, heavy-duty fans to maintain adequate ventilation,” continued McKernan.
The crew primed the deck with Kemper’s EP Primer with kiln-dried sand broadcast into it, and then they allowed the primer to dry and cure for a minimum of 12 hours. They next applied the waterproofing system. This was Kemper’s 2K-PUR resin mix system, which was used in conjunction with two layers of Dow’s 2-inch (5 cm) STYROFOAM HIGHLOAD 60. The drainage mat for the vegetation consisted of ZinCo’s Floradrain FD40-E and their Filter Sheet SF. But first, the crew needed to fill in the cups of the drainage mat with ZinCo’s Zincoblend.
ZinCo provided the expertise and product for the vegetation system since at the time, Kemper didn’t have its own proprietary system, and ZinCo was also able to landscape the living roof. Finally, “the balance of the assembly, which included additional Zincoblend, stone ballast, pavers, growth media, vegetation, trees, shrubs, asphalt walkways, and fountains, were installed by others, and four small balconies overlooking the roof garden were finished off with Kemperdur TC, colored aggregate, and Kemper’s 1K Deko Sealer. Once completed, the project yielded the largest green roof in the state at the time,” explained McKernan.
In terms of safety, McKernan explained that, “because the majority of this area was bounded by higher building walls (3 to 7 stories), there was no need to worry about perimeter warning devices. The one remaining wall was a four-foot-high [1 m] parapet wall.” Because Kemperol 2K-PUR is a solvent- and odor-free product, only paper masks were needed throughout most of the installation process. “However,” McKernan said, “as an added precaution, respirators were worn when the weather became very hot in late spring because of poor airflow due to the surrounding walls.” Large, construction-grade fans were also utilized to push air around to maintain proper ventilation.
The waterproofing product’s manufacturer, Kemper System, was brought in by Steffian Bradley Architects thanks to an American Institute of Architects (AIA) lunch-and-learn on fluid-applied waterproofing systems. Tim Sullivan, New England account executive for Kemper, explained that “there was discussion for about a year to finalize the particular specification.” In the end, the Kemper system was selected for a variety of reasons, including that “it was very important not to have airborne carcinogens and maintain an odor-free, harmless system,” he explained.
Kemper has enjoyed a working relationship with Titan Roofing for over 15 years; the two companies have collaborated on several projects, including one at Yale University and a number of others throughout the region. Kemper only uses certified and authorized installers, and Sullivan prides himself on providing a “premium product and premium value at premium cost that is also extremely versatile.” They’re used on anything from green roofing planters, below grade on building foundations, and even in reflective pools and fountains.
“It’s a cold, liquid-applied membrane,” Sullivan explained, “and it is fully bonded directly to the substrate so there is no air between the two…there is very little migration of water in between.” Sullivan stressed that the system Kemper provides is more than a coating, as it’s actually “fluid-applied reinforced. There’s no spalling and no migration, which is the biggest advantage.”
Defects in workmanship and materials are warranted for 20 years including both materials and labor, with patching being a simple option. As Sullivan described, you “locate the defective area, mechanically prepare it with abrasive wheels or sand paper, and apply solvent to remove and dust about 6 inches [15 cm] around the penetration/failure. No primer is needed as you simply apply new resin to the existing resin, creating a one-step application.”
Ultimately, the third-floor roof has become a park-like setting providing a peaceful environment with a purpose, allowing patients a welcome area of beauty and reflection. Not only is the roof artfully dotted with plants, but rainwater is collected and reused to irrigate the drought resistant landscaping.
Both Titan Roofing and Kemper System look forward to more projects in the future as well as the opportunity to make the Northeast a little more “green.”