Architecture is an opportunity. Every commission is filled with fresh chances to add tangible value to the place, the people, the owner, and greater world surrounding the project. The decisions made along the way define the results of the owner’s investment, challenging designers and builders to continually look for ways to maximize user benefits without adding expense to the project. A seemingly simple waterproofing rehabilitation project at Weber State University in Ogden, Utah provides an excellent example of increasing a building’s functional worth by rethinking space.
“Weber State is a long-standing client, and we’ve done everything from a three-building residential life campus to small patch-and-repair projects,” says Dale Thomas, project architect at MHTN Architects. Thomas is a detail-oriented designer with more than 35 years of hands-on experience. When MHTN was engaged to solve problems with the waterproofing system on the roof of the Stromberg Athletic Complex, the University, designers, and builders all saw a valuable secondary opportunity.
“The building’s existing waterproofing system had developed some leaks, causing minor issues,” says Thomas of the original cause for concern in the Stromberg Complex. Rebuilding the waterproofing system meant tearing up a roof-top plaza composed of stone pavers, a few benches, and small grass lawns. The University felt the plaza was underutilized and rebuilding as it was prior to construction simply didn’t make sense.
“This was great space right in the middle of the University’s physical education complex. It needed to be activated,” continues Thomas. “Pickleball is a fun new sport enjoyed by people of all ages. The space comfortably accommodated four courts.”
MHTN worked with the University and general contractor Okland Construction to repair the structural steel and integrate a completely new, warrantied, waterproofing system below the plaza as they readied the roof for the new courts. “With the waterproofing system rehabilitated, we then needed to think carefully about drainage, especially for the surface of the courts.”
Though the space was ideal, like tennis, legitimate pickleball courts require a post-tension concrete slab to eliminate joints on the playing surface and minimize concrete cracking. The courts need to be as flat as possible, yet still capable of efficiently draining water from the surface, and in this case, off of the building as well. Since the roof’s existing structural slab was sloped to drain, designers needed a void-filler between the structural slab and the underside of the courts’ post-tensioned slab. The fill needed to be lightweight to minimize additional structural loading and economically feasible within the budget. That’s where designers turned to a unique building material, Foam-Control Geofoam from ACH Foam Technologies.
“We’re used to working with tapered insulation to create a roof’s drainage slope,” continues Thomas. “However, this was kind of an upside-down situation where we were trying to eliminate most of the slope rather than add it.” Incorporating a two-stage drainage system, water on the court surfaces is shed to a center trench drain, accompanied elsewhere by the waterproofing system on the structural slab and roof drains. The geofoam profile had to deliver virtually flat courts yet still direct water to the trench drain.
The responsibility of overseeing the rehabilitation including the non-degrading geofoam blocks fell to Les Hamby of Okland Construction. Les was the superintendent in charge of construction and over a 22-year career with Okland, he’s built just about everything.
“The project was really about limiting the added weight on the roof and getting a very precise taper,” says Hamby of the primary construction challenges. This molded polystyrene rigid geofoam is a lightweight, cellular plastic material that is incredibly strong. Foam-Control Geofoam products range in compressive strength from 2.2 pounds per-square-inch (psi) at one percent deformation all the way up to 18.6 psi.
Working with surveyors onsite, once the structural slab was exposed a series of spot elevations were taken. The survey data was used to establish the exact geofoam profile required to fill the void between the roof and the post-tensioned slab. Meticulously defining the thickness of each piece of foam allowed designers to control positive drainage off the courts and make sure the total volume of added weight didn’t approach structural limitations.
“Accuracy in preconstruction is critical,” says Hamby of the need to take and validate precise survey measurements and translate them to shop drawings. Hamby had worked with rigid foam products before, using geofoam as a structural platform for concrete stadium seating raisers and knows the importance of every piece being cut, shaped, and placed exactly.
“The geofoam platform was about 10 inches thick in the middle and tapered to zero at the edges,” continues Hamby. The final deck height had to match the threshold of the plaza’s existing entry door, which couldn’t be changed, so each piece of foam across the whole roof was unique. “Getting precut pieces on the job site in a logical order really expedites the time it takes to lay down the material.”
Protecting the building from deterioration due to water infiltration will always be Hamby’s biggest concern. He recommends a triple check strategy to make sure things are watertight and he likes reliable, proven products in the solutions he builds. Thomas sees things much the same way, quality is always critical as is innovation in reuse.
“I think renovation is a big part of architecture. To repurpose this plaza to a completely new function is exciting,” says Thomas. “ACH Foam Technologies’ geofoam product was an important part of what made this transformation of space possible.”