The Veterans Memorial Auditorium in downtown Des Moines, IA was named to honor the World War II veterans of Polk County. The facility opened its doors on February 1, 1955, and over the years has been home to various sporting events, concerts and community activities.
Not long ago, the venerable old building’s single-ply membrane roof system failed. The cause was attributed to poor installation. However, when county officials sought a remedy they wanted a replacement system that offered a more long-term roofing solution. Metal fit that requirement. To assist with the 85,000 sq. ft. project Polk County officials enlisted the help of The Weitz Co., a Des Moines-based general contractor, and an Iowa-based design firm, OPN Architects. The job went out to bid and Academy Roofing & Sheet Metal Co. of Des Moines won the contract to remove the existing single-ply roof and replace it with an engineered metal system.
The job was challenging for a number of reasons. The eave height was 70’, the roof pitch was 4/12 and the length of the roof sheets needed to span from the roof ridge to a 15’-wide trough at the bottom was 120’. The trough was to be covered with a single-ply membrane. On top of that, the underlying structure consisted of a 3”-thick gypsum plank deck attached to I-beam joists on 8’ centers. Having trouble finding a manufacturer who could provide the ideal solution, Academy Roofing & Sheet Metal Co. turned to Houston-based Architectural Building Components.
“When Nick Parenza called and told us about the issues they were seeing at Vets, I knew this was perfect application for our 238T/FiberTite Hybrid roof system,” recalled Charlie Smith, president of Architectural Building Components. “They had structural attachment problems, wind uplift issues, snow loading and were extremely concerned about leaks. Also since the county was in for the long term, they would really appreciate the idea of being able to remove a panel from anywhere in the roof in the future if they ever needed to. They also wanted a single-source weathertight warranty that included the metal and the single ply. We chose to partner with Fibertite because they make the best single ply on the market.”
Terry Wolfe of Force Engineering & Testing was brought into the project to assist in the development of an engineered framing plan that provided attachment to the existing structure while meeting both the wind load and snow load requirements of the roof. Wolfe designed a framing grid system consisting of 4”-tall x 14- and 16-gauge zee purlins running uphill, and Architectural Building Components’ 1¾” tall x 16-gauge zee purlins running across and attaching to the structure below. The airspace between the two roofs would be filled with batt insulation.
Limited access from one side of the building further complicated the job. As a solution, Academy Roofing & Sheet Metal Co. erected a 70’-tall scaffold on the accessible side of the building. Atop that scaffolding they hoisted the Archzilla®, ABC’s 238T jobsite roll former. The machine formed 120’-long panels out onto the roof. The formed panels were stacked on one side of the building and then carried across for installation using 100% continuous clips. The continuous clips provided for a wind uplift resistance that was at least 3 times the requirement and also significantly increased the load carrying capacity of the panels. At the eave, the roof panels were fixed and a flap of FiberTite XT single ply was inserted.
Despite the challenges of the job, all parties worked together seamlessly to provide the best watertight solution for Polk County. The restoration of the roof has allowed the venue to continue to serve as a community asset while standing as a testament to those who served our country during World War II.