Pioneer Hall is a central fixture on the University of Minnesota campus. Built in 1934, the five-story structure serves as a freshman dormitory and dining hall. The building was almost totally rebuilt as part of a $104 million renovation project in 2019.
A key goal of the project was to keep the distinctive, highly visible brick facades on the four outer wings in place while totally replacing the main section of the building. Work included entirely renovating the interior, replacing all mechanical systems, and installing a new roof.
Working along with McGough Construction, the St. Paul-based general contractor on the project, Minneapolis-based Central Roofing Company installed the new roof systems on the building, which included 47,000 square feet of synthetic slate, as well as built-up roofs, EPDM roofs, and a garden roof.
Central Roofing has been in business since 1929, and the company is a fixture on the University of Minnesota campus. “We do a wide variety of different types of commercial roofs, ranging anywhere from flat to steep to sheet metal roofs,” says Michael Mehring, vice president of commercial sales for Central Roofing. “We also have a metal panel division. There is no system that we cannot do in regard to flat roofs. On steep roofs, we do both tile and shingle as well as sheet metal. In addition to that, we have one of the largest service divisions in the Midwest.”
The project involved multiple scopes of work, including the DaVinci Roofscapes synthetic slate on the steep-slope sections, Johns Manville built-up roofs on the main roof and green roof area, as well as sheet metal work, gutters and downspouts. Central Roofing developed a detailed plan to bid on all the scopes of work — and execute everything.
“The project was interesting in the sense that approximately 75 percent of the building was demolition,” notes Mehring. “That included all of the internal parts of the building. The four bays around the perimeter were saved because of historical ramifications. The university wanted to try and keep those four bays because of the distinctive windows and the brick. The middle portion of the structure was pretty much demoed out. So much internal work was needed on the mechanical and electrical systems that they couldn’t save it.”
Synthetic Slate Roof
Central Roofing worked closely with McGough Construction and the project architect, St. Paul-based TDKA Architects, to ensure the new synthetic slate roof system would closely replicate the structure’s original slate roof. According to Henri Germain, project manager/estimator with Central Roofing, the DaVinci Multi-Width Slate product was approved for the project because it so authentically duplicates real slate.
“We started by making presentations of product options to the project architect,” says Germain. “The architect moved forward with the DaVinci product because of the aesthetics, value, and long-term benefits to the university.”
Selection of a roofing color was also a critical factor. DaVinci created a custom color blend of dark purple, medium brown, dark stone, medium green and dark green for Pioneer Hall. “The capability of DaVinci to develop the custom color blend was amazing,” says Germain. “The roofing colors really complement the dormitory plus other structures on campus.”
Work began on the steep slope sections with the installation of the synthetic slate system on the brand-new metal deck. “From a scheduling standpoint, the first thing that we did was the tile areas,” Mehring recalls. “In order to maintain the milestones that McGough had, we had to essentially get them watertight within 60 days. To do that, we did the tile work in phases utilizing 15-20 workers every day.”
The men were split into three crews. A crew of six to seven roofers began installing the substrate board and Grace Ice & Water Shield, which served as the vapor barrier. The second crew came in behind the first to install the wood blocking and insulation, which was capped with plywood and covered with Grace Ice & Water Shield and GAF FeltBuster synthetic underlayment.
A third crew of four or five technicians then installed the DaVinci synthetic slate tiles. The product was easy to install, notes Germain, but the numerous details — including some 93 dormers — posed some challenges. Crews also installed RG 16 Snow Guards from Rocky Mountain Snow Guards Inc.
“There were many details, and because of the extreme difficulty in accessing the area after the scaffolding was removed, everything was treated as if it would never be returned to in the lifetime of the roof — not for caulking, not for anything,” Germain says. “The thought was to make sure it was done once and done right.”
As the tile work progressed, the sheet metal crew started installing the gutters. The waterproofing, gutter installation and tile application had to be coordinated carefully to make sure everything was tied in perfectly. “It was a sequencing nightmare,” says Mehring.
Central Roofing crews installed the wood blocking, sheathing and waterproofing in the decorative cornices, which had been recreated out of fiber reinforced plastic (FRP) by another subcontractor. Central Roofing then fabricated and installed the copper internal gutters, as well as the downspouts, which were constructed of pre-finished steel to match the window frames.
On the smaller flat roof areas abutting the steep-slope roof, a 60-mil EPDM system from Johns Manville was installed. These areas were completed as work progressed on each section.
On the low-slope sections of the main roof, crews applied a four-ply built-up roof system manufactured by Johns Manville. Approximately 31,500 square feet of JM’s 4GIG system was installed and topped with a gravel surface.
The built-up roof areas were bordered by parapet walls, which were east to tie into, notes Mehring. “What made this project a tad bit easier is that the other scopes of the work — the flat roofs — didn’t have too many sequencing issues with the tile work and the gutters,” he says. “The built-up roofers were on their own and had their own schedule.”
On the 13,000-square-foot area for the green roof, a Johns Manville three-ply system with a modified cap sheet was installed. The green roof features a built-in leak detection system from International Leak Detection (ILD). “The leak detection system is encapsulated between the polyiso and the cover board,” notes Mehring. “We installed a JM modified cap sheet. All of the seams had to be reinforced with their PermaFlash liquid membrane to maintain the warranty because of the green roof.”
Challenges on the project included a tight schedule and difficult weather. “Essentially we had a 40-day schedule to get all of the built-up roofing on,” Mehring says. “The challenge with not only the built-up but the tile as well is that the work started in the late fall and we had to work through the winter. You can imagine the problems with the Minnesota weather.”
Days were lost to rain, snow, cold temperatures and high winds. The green roof system couldn’t be completed until May, near the end of the project, when Central Roofing installed the growing medium and plants. After a drainage layer was installed over the cap sheet, crews applied engineered soils and sedum mats supplied by Hanging Gardens, Milwaukee, Wisconsin.
Access at the site was also difficult. Central Roofing used its Potain cranes to get materials on and off the roof. “Those self-erecting stick cranes can go 120 feet up in the air and they also have the ability to deliver materials 150 feet from the setup location,” Mehring explains. “That was critical because we only had two locations we could set up: on the south side, in between the opening of the two wings, and on the north side, also in the opening between the wings. We had to have the ability to get material to the middle section and the corners of all four wings, and that was the only way to do it.”
Another logistical challenge was posed by a large tree at the southeast corner of the building — the oldest tree on campus. Great care had to be taken to avoid damaging it. “The tree goes as high as the steep roof, and you had to work right by it,” notes Germain. “While working and using the crane, we couldn’t touch it. The guys were very careful and very conscious of it. Adam Fritchie, the foreman on the project, did a great job communicating with the university and the crews to make sure everyone understood the project goals.”
As part of the site-specific safety plan, crew members were tied off 100 percent of the time on the steep-slope sections — even with scaffolding in place for the project. The flat roof areas were bordered by parapets, but they were only 2 feet high, so safety railing systems were installed. “We used Raptor Rails all the way around, and when we were installing the railings, we used Raptor carts,” Mehring says. “Our men were fully tied off while installing the railings — and taking them down.”
It was a complicated project, but executing complicated projects with multiple scopes of work is one of the company’s strengths. “Overall, I think we had more than 20,000 hours on this project,” Mehring says. “So, I think that a roofer having the ability to garner 20,000 hours on a project speaks for our ability to finish large and challenging projects within the milestones required — as well as keeping safe protocols and paying the bills. The tile, the copper, the sheet metal, the built-up roofing, the green roofing, the EPDM — all of those were self-performed by our guys.”
“This was such a special project,” Germain says. “Aside from the sheer size, it captures the heart. When we look at the finished structure we’re extremely proud. Our team, which also included Lloyd Carr, Matt Teuffel and Corey Degris, played a big part in re-establishing Pioneer Hall as a key building on the University of Minnesota campus.”
Architect: TDKA Architects, St. Paul, Minnesota, www.tkda.com
General Contractor: McGough Construction, St. Paul, Minnesota, www.mcgough.com
Roofing Contractor: Central Roofing Company, Minneapolis, Minnesota, https://www.centralroofing.com
Synthetic Slate: DaVinci Multi-Width Slate, DaVinci Roofscapes, www.davinciroofscapes.com
Built-Up Roofs: Four-ply 4GIG system and, Johns Manville, www.JM.com
EPDM Roof: 60-mil EPDM, Johns Manville
Vapor Barrier: Grace Ice & Water Shield, GCP Allied Technologies, www.gcpat.com
Underlayment: FeltBuster synthetic underlayment, GAF, www.GAF.com
Leak Detection System: International Leak Detection, https://leak-detection.com
Snow Guards: Rocky Mountain RG 16 Snow Guards, Rocky Mountain Snow Guards Inc., www.rockymountainsnowguards.com
Green Roof: Sedum mats, Hanging Gardens, Milwaukee, Wisconsin, www.hanging-gardens.com