New NHL Practice Facility and Community Center Sports Vegetative Roof

The American Hydrotech Extensive Garden Roof Assembly was installed on two sections of the roof. The system was topped with pre-grown mats featuring mature sedum plants. Photo: American Hydrotech Inc.

The Chicago Blackhawks have captured the hearts of the city of Chicago along with three Stanley Cups in the last decade. The Blackhawks routinely lead the league in attendance at the United Center, and fans were excited when the team announced it would build a new 125,000-square-foot training facility and community center in downtown Chicago.

Completed earlier this year, the MB Arena features two NHL-sized ice rinks and other amenities including a fitness center, dining options, and spaces that can be rented for outings and events. The facility is the practice site for the Blackhawks and also hosts youth hockey, adult hockey leagues and public skating.

When plans for the project were unveiled, architects and planners mandated the facility meet or exceed all green and sustainable standards for the city. Chicago has been a leader in promoting vegetative roofs to help control storm water runoff, and this new construction project was no exception. The arena includes the construction of 24,000 square feet of green roof systems to complement the structure’s 68,000-square-foot main roof. A 60-mil TPO system manufactured by Carlilse SynTec was specified for the upper roof assembly, and plans called for an American Hydrotech Extensive Garden Roof Assembly to be placed on two lower sections of the roof.

The Garden Roof Assembly

Architect HOK worked with American Hydrotech during the design stage to select roofing components and plants that were optimized for the climate conditions and the building’s structural limitations.

According to Dennis Yanez, national marketing manager, American Hydrotech, and Kevin Serena, garden roofing technical sales coordinator for the central region, the structure’s metal deck necessitated a lightweight system.

The 125,000-square-foot facility 24,000 square feet of green roof systems that complement the structure’s 68,000-square-foot main roof. Photo: Chicago Blackhawks.

“Our 4-inch extensive garden roof system was ideal for this project,” says Yanez. “Since part of this project had a metal deck, there are more structural capacity concerns than with a concrete deck, so we were able to put together a lightweight, built-in-place system.”

The assembly consists of a hot-applied rubberized asphalt membrane, MM6125, which is applied to the roofing substrate to form a monolithic coating. It is topped with a root barrier and Dow Styrofoam insulation. The system also incorporates Hydrotech’s Gardendrain GR15, a molded polyethylene panel designed to retain water, filter fabric, lightweight growing media, and mature plants.

The plants are installed in the form of the InstaGreen Sedum Carpet, a pre-grown mat that comes in 25-square-foot rolls. It contains between nine and 15 different types of sedum and provides instant coverage when it is installed.

Key benefits of the system include reducing the urban heat island effect, purifying the air, and limiting storm water runoff, notes Yanez. “The Extensive Garden Roof Assembly is able to capture more than 1.5 inches of water on the roof, which plays a major role in storm water management,” he says.

The system also protects the membrane from ultraviolet (UV) degradation and damage from wind-blown debris. “Most importantly, for us, a garden roof is just another version of a PMR, or protected membrane roofing,” says Yanez. “Because the membrane is always in a PMR application, with Dow insulation over it, whatever ballast — whether it’s gravel ballast, or architectural pavers, or the garden roof assembly — is in place makes it literally impossible for the membrane to get damaged. It also mitigates the climate swings, keeping the membrane at a more constant temperature year-round.”

This system has a proven track record, according to Yanez. “We’ve been doing this going back 50 years on parking decks under regular topsoil, where weight wasn’t a concern,” he points out. “This is just a more modern version of that, but we’re putting it on the 4th, or the 14th, or the 99th floor.”

The Roofing Installation

All American Exterior Solutions, Lake Zurich, Illinois, is an approved applicator for both key manufacturers. The union contractor installed the Carlisle TPO system on the building’s main roof and the Hydrotech green roofs on the two lower roof levels.

Willie Hedrick, division manager at All American Exterior Solutions, notes that the TPO roof was installed first. “The deck was acoustic, so first we had to lay strips insulation in the flutes over the entire main roof,” he says.

The lightweight growth media was lifted to the roof in 2-yard totes. Photo: Christy Webber Landscapes.

Areas that housed mechanical equipment were reinforced with two layers of 5/8-inch DensDeck from Georgia-Pacific. Two layers of 2.6-inch insulation were then installed, followed by the 60-mil TPO, which was mechanically attached using the RhinoBond system from OMG Roofing Products. The attachment system uses induction welding technology to attach the membrane to the fasteners and plates that secure the insulation — without penetrating the membrane.

The main roof was originally designed as fully adhered system, but work began in January, and the temperature constraints ruled out some adhesives. “Once we made the switch to RhinoBond, we were able to install the membrane even though we did it during the winter,” Hedrick says.

Most of the TPO roof was surrounded by high parapet walls, and in other areas the safety perimeters were marked with flags. “At a few points at the highest points of the main roof we had to put up some the flags, and if you were outside of the flags you had to be tied off,” notes Hedrick. “The mid-roofs had short parapet walls, and on those roofs, we set up flags and had 100 percent fall protection outside the safety perimeter. For the lower green roof, we put guardrails up on the parapet to eliminate the fall hazard.”

The Garden Roofs

After the TPO sections were installed, work began on the extensive garden roof assemblies. The mid-roof had a metal deck, so the first step was to screw down 5/8-inch USG Securock cover board and strip in the seams. “At that point, we installed the liquid-applied membrane and the protection board,” Hedrick says.

The second green roof was installed over a concrete deck, so the application was a bit different. The membrane was applied directly to the concrete. A late change was made in the configuration of the lower green roof to take advantage of the space. “The owner decided to add a terrace to the lower green roof so people could walk out and see the roof and views of the city,” Hedrick recalls.

Before the growing media and plants were added, electronic field vector mapping (EFVM) was conducted by International Leak Detection to determine if there were any voids in the membrane. “You’ve got to confirm everything is 100 percent watertight before we start setting the components down,” Hedrick says. “We usually do the test and start putting the components down the next day to minimize exposure. The subcontractor we worked with to do the landscaping, Christy Webber, performed well. Since some of the components are loose laid, we worked with them to put down enough soil to hold everything in place. We worked hand-in-hand getting the all of the components and soil in.”

The Landscape Work

Jim Waldschmidt, project manager for Christy Webber Landscapes, Chicago, oversaw the installation of the lightweight growing media and sedum mats on the roof. Christy Webber is a full-service union landscaping company, and Waldschmidt notes that roofing work is a small but growing share of the company’s business. “We work with a few different commercial roofers,” he says. “This year we’ve done maybe 10 commercial projects.”

After the growing media was evenly spread out, the sedum mats were laid into place by crews from Christy Webber Landscapes. Photo: Christy Webber Landscapes.

Logistics at the site made for an easy delivery and setup — an unusual situation in downtown Chicago. “We were able to deliver the soil almost a week before we were scheduled to go out there, so we had everything on site and knew we wouldn’t have to worry about waiting,” Waldschmidt notes. “We just had to bring in a crane and lift up the soil bags. We had a pretty easy installation compared to other green roofs we’ve done.”

Growing media was lifted to the roof in 2-yard tote bags, which were cut open to disperse the contents. Three days after the growing media was in place, Christy Webber crews returned to install the sedum mats. “The sedum mats are delivered on pallets almost like the way a roll of sod would be delivered,” says Waldschmidt. “We just had to set the pallets on the roof, pull off the sedum mats and unroll them.”

A temporary irrigation system was set up to help the plants get established in the hot July temperatures. “Everything looks great now,” Waldschmidt says. “All of the sedum up there is thriving.”

Growth Sector

In this high-profile project, with a high-profile owner, making sure the system was error-free was critical, notes Serena. “Chicago is definitely the leader in vegetative roofs, and has been for more than 10 years,” he says. “This is another prime example. There was never a question whether this building would have a green roof on it. It’s a credit to Chicago, and it is a credit to the Chicago Blackhawks.”

Hedrick is proud to be part of the green roof movement. “I like the challenge, and I like the diversity,” he says. “When the Blackhawks went to the Stanley Cup championship and the blimp was hovering over the arena, I could see a couple of my projects on TV. It reminded me of all the time, effort, attention to detail, and collaborative hard work that it took to produce the final product. We’re turning typically unusable roof areas into useful space for amenities.”

The key driver of green roofs is storm water management, notes Yanez, but turning rooftops into useful space is another key benefit. “We’re seeing more and more city incentives for storm water management,” he says. “In urban areas, people are also taking advantage of existing space with green roofs. It’s a growing industry — pun intended.”

TEAM

Architect: HOK, Chicago, www.HOK.com
General Contractor: James McHugh Construction, Chicago, www.McHughConstruction.com
Roofing Contractor: All American Exterior Solutions, Lake Zurich, Illinois, www.AAEXS.com
Landscape Contractor: Christy Webber Landscapes, Chicago, www.ChristyWebber.com

MATERIALS

Garden Roof System:
Cover Board: Securock Gypsum-Fiber Roof Board, USG, www.USG.com
Membrane: MM6125 hot rubberized asphalt membrane, American Hydrotech Inc., www.HydrotechUSA.com
Protection Sheet: Hydroflex 30, American Hydrotech Inc.
Root Barrier: Root Stop, American Hydrotech Inc.
Insulation: DOW Styrofoam, DOW Chemical, www.Dow.com
Drain Board: Gardendrain GR15, American Hydrotech Inc.
Filter Fabric: System Filter fabric, American Hydrotech Inc.
Growing Media: LiteTop Engineered Growing Media, American Hydrotech Inc.
Plants: InstaGreen Sedum Carpet, American Hydrotech Inc.

TPO Roof System:
Membrane: 60-mil TPO, Carlisle SynTec, www.CarlisleSyntec.com
Cover Board: DenDeck, Georgia-Pacific, www.BuildGP.com
Attachment System: RhinoBond, OMG Roofing Products, www.OMGroofing.com

TPO System Delivers Energy Efficiency for Company Headquarters

TurnKey Corrections constructed a new 115,000-square-foot in facility in River Falls, Wis.

TurnKey Corrections constructed a new 115,000-square-foot in facility in River Falls, Wis.

If you want it done right, do it yourself. Company owners Todd Westby and Tim Westby take a hands-on approach to running TurnKey Corrections, the River Falls, Wisconsin-based company that provides commissary and jail management services to county corrections facilities nationwide. The Westby brothers also take pride in the fact that TurnKey manufactures the kiosks it provides to its clients and develops and owns the proprietary software used to run them.

So, it’s perhaps not surprising that, when building the company’s new headquarters, Todd Westby, the company’s CEO, founder and general manager, served as the general contractor. Or that he had definite ideas regarding the roofing system that would be installed. Or that he was more than willing to get his hands dirty during the installation process.

Founded in 1998, TurnKey Corrections helps corrections facilities streamline and lower the cost of delivering a variety services to inmates, including commissary, email and email-to-text communication, video visitation, law library access, and paperless intra-facility communication and documentation. Following several years of robust growth, the company had outgrown its three existing buildings. So, it constructed a new 115,000-square-foot facility to bring all operations, including 50,000 square feet of office space and a 65,000 square-foot warehouse where commissary items are stored prior to shipment to corrections facilities, under a single roof and accommodate future success.

“We wanted to be involved in the project from beginning to end so we knew what we were getting and how it was built,” Todd Westby says of the decision to keep construction management in-house. “We wanted to know about anything and everything that was being built for the company in this building.”

In planning the project, Westby initially set two key criteria for the roofing system: that the building would be made watertight as quickly as possible so concrete slab pours and other interior work could be completed, and that the roof would be covered by a warranty of at least 20 years. The design-build firm’s initial plans called for a ballasted EPDM roofing system, but Rex Greenwald, president of roofing contractor TEREX Roofing & Sheet Metal LLC of Minneapolis, suggested a white TPO system, noting that it would meet the quick installation and warranty goals while also enhancing the building’s energy efficiency. Westby was intrigued and, after some research, agreed to the recommendation. In addition to helping reduce cooling costs during summer months, the reflective surface would allow a blanket of snow to remain on the roof during winter months to provide additional insulation.

The TPO roofing system was constructed over a 22-gauge metal fabricated roof deck.

The TPO roofing system was constructed over a 22-gauge metal fabricated roof deck.

The Roof System

The TPO roofing system included a 22-gauge metal fabricated roof deck; two 2.5-inch-thick layers of Poly ISO insulation from Mule-Hide Products Co., with tapered insulation saddles and crickets to aid drainage; and 811 squares of 60-mil white TPO membrane from Mule-Hide Products Co. The insulation and membrane were mechanically attached using the RhinoBond System from OMG Roofing Products. Cast iron roof drains, designed and installed by a plumber, were used rather than scuppers and downspouts—a practice that the TEREX team strongly recommends to prevent freezing during the cold Upper Midwest winters. Walkways lead to the mechanical units, protecting the membrane from damage when maintenance personnel need to access the equipment.

The TEREX team finds the RhinoBond System to be the most efficient and economical attachment method for TPO systems. Specially coated metal plates are used to fasten the insulation to the roof deck and then an electromagnetic welder is used to attach the membrane to the plates. The membrane is not penetrated, eliminating a potential entry point for moisture. And while other mechanical attachment methods require the crew to seam as they go, the RhinoBond System allows them to lay the entire membrane (a task which must be completed in good weather conditions) at once and go back later to induction weld the seams and plates, which can be done when Mother Nature is slightly less cooperative.

Greenwald estimates that the switch from the originally specified ballasted EPDM system to the TPO roofing system and RhinoBond System shaved at least 10 percent off the installation time and reduced the roof weight by 10 pounds per square foot.

Having Westby on-site as the general contractor also sped up the project considerably, Greenwald notes. “He was a huge asset to all of the subcontractors,” he explains. “We could get construction questions answered quickly and could talk through issues and procedures on a timely basis.”

And the most memorable moment in the project for Greenwald was seeing Westby working side-by-side with his crew. “One day we had a delivery truck show up, and Todd jumped on the forklift and helped us unload the truck.”

As sought from the project’s outset, the roofing system is backed by a 20-year, no-dollar-limit labor and material warranty.

With one winter of use in the rearview mirror, the roofing system has exceeded Westby’s expectations. Warehouse space was doubled, but heating costs have been cut in half. The 10-unit heating system also is able to keep the warehouse a uniform temperature, without the cold spots that were common in the old building.

“It really is a beautiful, very efficient and organized-looking roof,” Greenwald says.

Green Roof Provides Learning Opportunities at the University of Iowa’s Pappajohn Biomedical Discovery Building

Established just 59 days after Iowa became a state in 1847, the University of Iowa, Iowa City, boasts a number of firsts. In 1855, it became the first U.S. public university to admit men and women; at that time, its enrollment consisted of 124 students—41 of which were women. In 1873, it was the first school to grant a law degree to a woman. In 1895, it became the first university to place an African American on a varsity sports team.

As such, the university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. PHOTO: Roof Top Sedums LLC

The university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. PHOTO: Roof Top Sedums LLC


In more recent years, the university has strived to lead via its environmental efforts. As a Green Power Partner of the Washington, D.C.-based U.S. Environmental Protection Agency, the university pledges to reduce the environmental impact of electricity generation through the use of renewables. In 2010, it established its first sustainability plan—2020 Vision UIowa Sustainability Targets, which contains the following goals:

  • Become a Net-negative Energy Consumer
  • Green Our Energy Portfolio
  • Decrease Our Production of Waste
  • Reduce the Carbon Impact of Transportation
  • Increase Student Opportunities to Learn and Practice Principles of Sustainability
  • Support and Grow Interdisciplinary Research in Sustainability-focused and Related Areas
  • Develop Partnerships and Advance Collaborative Initiatives, both Academic and Operational

Among the University of Iowa’s strategies to achieve its sustainability goals is ensuring all new construction and major renovations on campus achieve a minimum LEED Silver certification from the U.S. Green Building Council, Washington.

The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes.

The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes. PHOTO: Scott Nagel


As such, the university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes, including glow-emitting sealants, paints, carpet and other materials; water-efficient landscaping; and recycled content and regional materials. It also achieves an-other university first: three green roofs, one of which provides students the opportunity to grow medicinal plants.

Opting for Trays

Des Moines, Iowa-based landscape architecture firm Confluence has been completing projects at the University of Iowa for many years through its Iowa offices—Des Moines and Cedar Rapids. Confluence was hired by the project’s architect of record, Rohrbach Associates PC Architects, Iowa City, to complete landscaping around and on top of the Pappajohn Biomedical Discovery Building in the form of three green roofs that total approximately 6,440 square feet. Despite the building’s consider-able roof area, the design team opted to install the green roofs on lower roof areas upon which building occupants would be looking. The rest of the roof cover is a reflective membrane system.

Confluence provided the layout for a modular green roof on the three distinctive roof areas. Patrick Alvord, PLA, RA, LEED AP, a principal in Confluence’s Cedar Rapids office, notes the chosen tray system was off-the-rack, which is what made it appealing to him and his colleagues. “We spent a lot of time talking to the manufacturer and they were just great to work with,” Alvord says. “We had a number of case studies of work they had done in the Chicagoland area that had proven very successful, so we had a very high level of comfort right out of the gate.”

Alvord opted to use the 6-inch-deep tray model because it would provide some flexibility in the plant materials that could be specified. “We were able to specify different plant materials in the plan of the roof to coordinate with shade, densities and location,” he says. “In areas where the roof would be highly visible from floors above, we did some patterning with the plants. In areas where we had the opportunity to go deep, we planted deeper-rooting plants that will grow taller and provide a denser plant palette.”

The plants are a mix of native and adaptive Iowa plants, as well as recommendations from the green-roof supplier. “It’s a mix of perennials, grasses and forbs, ranging from sedums to liatris to a number of different things,” Alvord notes.

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