Roofing a powerhouse

Corporate Contractors helps build a new recreational facility at Beloit College

  • The Powerhouse during renovations
  • The smokestack no longer is operational, so a domed
skylight was added to its base.
  • A southern view of The Powerhouse
  • Before (inset photo) and after views of The Powerhouse’s
  • Before (inset photo) and after views of the natatorium

Situated on the banks of Rock River and surrounded by Native American burial mounds, Wisconsin’s Beloit College is a private liberal arts college with 1,275 undergraduate students. Founded in 1846, the college is celebrating its 175-year anniversary this month, remaining the oldest continuously operating college in Wisconsin.

During 2018-20, a new, seven-story central campus gathering space called The Powerhouse was created by transforming the century-old, decommissioned Blackhawk Generating Station into a 120,000-square-foot building that combines student union, health, recreation, fitness and athletics facilities. Selected for its previous experience working with Beloit College, Corporate Contractors Inc., Beloit, managed the project and installed the new roof systems.

“Corporate Contractors has worked with Beloit College in the past, including serving as the general contractor for the college’s Hendricks Center for the Arts,” says Homer Auge, roofing project manager for Corporate Contractors. “We are deeply committed to our hometown of Beloit and are actively involved in the community. Our company has a long history of participating in projects that have enhanced the economic health and quality of life in Beloit. We also have extensive experience with adaptive reuse projects, so when Beloit College began planning The Powerhouse, we were excited to be a part of it.”

About The Powerhouse

The Powerhouse provides Beloit College students a central gathering space for the first time in 30 years and is the first campus building along the river. It combines student life and recreational facilities, connects the campus to the community and pays homage to the city’s history.

The Blackhawk Generating Station was a fixture in Beloit for more than 100 years. Wisconsin Power and Light Co., now part of Alliant Energy,® began constructing the original red brick building in 1907. By 1925, the building had been expanded four times. To meet growing demand for electricity following World War II, a cream-colored brick addition was erected in two phases between 1945-46 and 1948-49. The power plant remained operational until 2009, and decommissioning was completed in 2010.

Soon thereafter, the college’s president, Scott Bierman, had an idea to turn the building into a one-of-a-kind recreational center. Although portions of the building needed significant restoration, including the roof systems, the steel-frame brick structure was sound.

A partnership between Beloit College, Alliant Energy and the City of Beloit was formed. About $28 million in private donations were raised for the project, and $10 million in state and federal historical preservation and new market tax credits were secured.

Because the Blackhawk Generating Station was added to the National Register of Historic Places in 2017 and the rehabilitation project received state and federal historical preservation tax incentives, the products and construction techniques used to create The Powerhouse had to reflect those used when each section of the building originally was constructed.

Building The Powerhouse

The Corporate Contractors team began working on the project in July 2018. The Powerhouse is a combination of existing and new construction structures.

Unit 1 was completed in 1913 and has a roof area of about 10,500 square feet on a wood plank deck.

Unit 2 was built in 1927 and has a roof area of about 4,500 square feet on a concrete roof deck.

Units 3 and 4 were built in the 1940s and have a total floor space of 96,000 square feet and a total roof size of about 22,500 square feet. The portion above the original turbine hall had a roof deck made of precast concrete panels, and the remaining area had a concrete roof deck. Unit 3 also features a 100-foot-tall smokestack.

The fieldhouse was built in 2020 and has a roof area of 17,000 square feet on an 18-gauge Type N metal roof deck.

Before working on the roof areas, the Corporate Contractors team set up a flagging system and installed temporary guardrails over coping caps.

“In most areas, the parapet walls were high enough that additional safety precautions were not needed,” Auge says. “Where parapet walls were shorter and harnesses were necessary to ensure crew safety, the team took great care in placing the anchors to protect the finished wall faces on the historical building.”


The crew used roof cutters and tear-off tools to remove the existing 38,347 square feet of built-up roofing and then loaded the debris on a crane to remove it from the rooftops. The Corporate Contractors team worked right behind the demolition team, installing new roofing materials on sections as they became available.

“Even after the primary work on a section was complete, we would return to the job site as needed to flash around penetrations for HVAC equipment, exhaust stacks, conduit and line sets,” Auge explains.

The existing wood roof deck on Unit 1 was badly deteriorated, so workers replaced it with a Vulcraft® 22-gauge steel deck. Considerable tuckpointing also was required to address structural issues on the brick parapet walls. Given the building’s historical status, the concrete caps had to be replaced with new ones that matched. The caps were procured and installed by Statz Restoration and Engineering Co. Inc., Menomonee Falls, Wis.

The concrete and precast concrete roof decks on Units 2, 3 and 4 were retained. However, the decks ranged between 60 and 90 years old. The precast concrete panels on Units 3 and 4, where the power plant’s turbines were located, required significant repairs. The Corporate Contractors crew fully restored these areas to original specifications.

New roof systems

Next, workers applied two layers of 3-inch-thick Mule-Hide Poly ISO Flat insulation to achieve an R-value of 34.8. To ensure positive drainage in certain areas, workers applied Mule-Hide Poly ISO Tapered insulation following a taper schedule created by the Tapered Solutions team at ABC Supply Co. Inc., Beloit.

When choosing the type of new roof systems to install, the college’s project managers called on the Corporate Contractors team for help.

“The building is complicated,” says Daniel Schooff, chief of staff and college secretary for Beloit College and project manager for The Powerhouse project. “The power plant was constructed in four phases spanning 40 years plus we built a 17,000-square-foot addition. We also had some unique requirements related to historical preservation. We turned to the experts at Corporate Contractors to recommend the roof systems that would perform best.”

The team selected white 60-mil-thick TPO membrane for Units 2, 3 and 4. Because the roof on Unit 1 is visible from the ground, the roof’s color needed to match the original black roof. Accordingly, a black 60-mil-thick EPDM membrane was selected.

Workers fully adhered the TPO and EPDM membranes to the various roof decks using AeroWeb Low-VOC Contact Adhesive/Primer.

“With concrete roof decks on Units 2, 3 and 4, a fully adhered system was the right approach,” Auge says.


Although the building’s iconic 100-foot-tall steel smokestack no longer is operational, it was preserved as a lasting landmark and a reminder of the building’s history. Rather than capping the smokestack at the top and bottom, a domed skylight was installed at the smokestack’s base, giving building occupants a view of the sky above.

The skylight was slightly smaller than the opening on the roof deck’s underside, allowing workers to raise it into place on a curb fabricated by Corporate Contractors craftsmen who then flashed it with 60-mil-thick EPDM.

The skylight now is a signature feature of The Stack—a conference and event space ready for large gatherings such as weddings and campus and community events post-COVID-19. But for now, it serves as the site for the college’s COVID-19 testing program.

New fieldhouse

The Corporate Contractors team completed reroofing work on The Powerhouse’s original structures in January 2020. In May 2020, the crew began work on the fieldhouse.

Workers placed two layers of 3-inch-thick Mule-Hide Poly ISO Flat insulation over the roof deck and then adhered 60-mil-thick TPO membrane using AeroWeb Low-VOC Contact Adhesive/Primer. To trim the roof system and exterior walls, workers used 24-gauge clear anodized metal.


Because of insufficient on-site storage space, materials were delivered in five stages: one for each unit plus the fieldhouse. Accessing the roof areas five stories above ground was challenging because Rock River was on the building’s west side and vehicular traffic was on the east side.

For most roof sections, workers used cranes to load materials and remove debris. For a section on the building’s west side along the river, workers were able to transport materials into the building. Then, they used a Lull 10K-54 Telehandler to lift materials to the roof and remove debris through an old window.

Workers accessed the rooftops using a variety of scaffolding and lift equipment including boom lifts, scissor lifts, swing-stage scaffolding on the river-facing side and a Vanguard Hydro-Mobile Mast-Climbing Platform on the street-facing side.

During the power plant’s decommissioning process, the plant was gutted, eliminating access to the roof from inside the building. To overcome this obstacle, the crew used silo ladders and scissor lifts outside the building to ascend to the lowest elevation and then used ladders to move to and from the higher elevations.

“With 10 elevations spanning from 40 feet to 95 feet above ground, it was a time-consuming and physical challenge,” Auge says.

Powering ahead

By August 2020, the Corporate Contractors team installed 44,000 square feet of TPO membrane and 10,500 square feet of EPDM on The Powerhouse. Thanks to the team’s dedication to historically preserving the structure while restoring the roof systems, the decommissioned power plant was successfully transformed into a riverside gem that serves as a central hub of campus life at Beloit College and a vibrant gathering space for the entire Beloit community.

In 2018, The Powerhouse project was selected as the overall winner of the World Architecture Festival, which honors future projects that identify key ecological and societal challenges that architects are actively seeking to address during the next decade. Among the features of The Powerhouse are radiant panels integrated into building surfaces that harness energy from the adjacent river’s water to meet much of the building’s heating and cooling needs, minimizing energy consumption and costs while also enhancing occupant comfort and maximizing air quality.

“This building is a prominent fixture in town,” Auge says. “It’s right on Rock River and on the main drag. It had been vacant for years. Bringing it back to life was a great reward.”

Chrystine Elle Hanus is Professional Roofing’s associate editor and an NRCA director of communications.

Project name: The Powerhouse at Beloit College
Project location: Beloit, Wis.
Project duration: July 2018-August 2020
Roof system types: EPDM and TPO membrane
Roofing contractor: Corporate Contractors Inc., Beloit, Wis.
Roofing manufacturers:Mule-Hide Products Co. Inc., Beloit; Vulcraft,® a division of Nucor® Corp., Charlotte, N.C.

The Powerhouse features include:

  • 10,000-square-foot fitness center
  • 17,000-square-foot O’Neill Fieldhouse with artificial turf
  • Three-lane indoor running and walking track
  • Robert G. Nichols Natatorium with an eight-lane competitive pool
  • Weissberg Auditorium, a 160-seat lecture hall and theater
  • Hamiltons Café
  • Recreation room and arcade
  • The Stack conference and event space
  • Health and wellness center
  • “Hub” spaces for campus organizations
  • Collaborative meeting rooms, seminar rooms and worktables
  • Gathering areas, nooks and “hang-out” spaces
  • Outdoor decks overlooking Rock River and a new Riverwalk



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