There’s not much use for a tape measure on this construction job. “I don’t think there is a corner here,” said David Calhoun, project manager for Skanska USA Building Inc., the construction management company overseeing the project. “On most jobs, you just find a corner and use your tape measure. Here, we use GPS coordinates.”
The job is the spectacular curving structure of the Innovation, Science and Technology Building at Florida Polytechnic, a new four-year university in the small town of Lakeland, Fla. Designed by world-renowned architect Santiago Calatrava, the eye-shaped building is a futuristic 120,000-square-foot facility that will house classes, laboratories, administration and common areas.
Architectural Roofing & Waterproofing got a rare insider’s look at this hallmark project during the construction phase. This building is the centerpiece of a high-tech campus that will focus on engineering, applied research and technology.
A Lot of Math
All that algebra and trigonometry taken in school can be found on this project. There are several elaborate architectural features that make the building look like a spaceport for alien ships. Rimming the outside are giant curved aluminum pergola arches painted white that temper the sunlight striking the walkways below. Reflective sloped glazing panels cover the ridge of the roof, which has 94 white operable louver arms (brise-soleil) that can be raised and lowered, depending upon the intensity of the Florida sun. All of these features created numerous penetrations that had to be sealed.
This thoroughly modern and clean look needed an integrated membrane that would keep the building dry and accommodate all of the trades during construction. Kemperol from Kemper System America Inc. was selected because the cold-applied resin creates a monolithic roofing system that dries quickly enough for foot traffic later that same day.
“It provides a lot of benefits to us in terms of construction sequencing,” Calhoun said. “I’ve grown to appreciate that once we’ve applied this, it’s secure and waterproof. It’s the right product put on the right project.”
Once in place, most roofs don’t appreciate much traffic. With up to seven trades on the roof at one time, the demands on the system were great from the beginning. The roofing contractor, TarHeel Roofing Inc. of nearby St. Petersburg, Fla., was installing the roof rather early in the process to protect the building contents and equipment going in. President John Looney knew from several projects in the past that the Kemperol would provide a membrane that sealed quickly enough for electrical contractors and metal workers to get to work.
“The system is pretty rigid,” said Looney, who started TarHeel Roofing in 1981 with his brother, David. “The product forms a pretty hard barrier in just a few hours, and it’s a product that’s going to perform for a long time.”
“It’s been unique,” he continued. “It’s as much a piece of art as a functional building.”
A Fluid Process
Water is a dominant feature in the project, as well as a constant presence during the construction process. Most Florida summers feature a daily thunderstorm in the afternoon that quickly passes, but in 2013 there were times when it rained all day.
“We anticipated starting it earlier then the summer, but that didn’t happen,” said Chuck Jablon, vice president of operations for Skanska. “We tried everything to work around the rain. Anything this complex ... we’re open seven days a week and facilitating whatever comes our way.”
The rain delays ate up quite a bit of the schedule. Even the humidity at night was sometimes too high for application of the membrane, so by November there were trades on the jobsite every day. Jablon, whose company had worked with the architect from the very beginning, had assembled a strong team of contractors who had to work in concert, like a conductor guiding his orchestra through a very complex symphony. The natural tension between trades competing for space and time gave way to harmony.
“They compete, but they compete knowing the rules,” he said. “There’s a lot of give and take on both sides. Today, we’re a happy family.”
That harmony is obvious on the jobsite. There are 68 different bid packages, and most are there each day. The fast-drying resin meant that after installing the roof in the morning, the other contractors could have their crews walk on the surface and do their work in the afternoon. Jablon even makes a weekly lunch for staff, and they often eat communally during the work week.
The lower terraced deck roof is 30,791 square feet that will be used for pedestrian traffic and will be sandwiched between layers of concrete. TarHeel installers attached the Kemperol system directly to the structural concrete deck, then put in a drainage mat. Two layers of 2-inch expanded polystyrene were attached with foam, then another layer of concrete was poured with a small slope, ¼ inch:12 in some places.
Since repairs to such a roof would be a nightmare, each section was subjected to a “swim day” before the insulation was installed. The drains were clogged and the roofs were filled with water right up to the windows for 48 hours to ensure a watertight seal. According to Looney, his crews could install about 15 squares on a good day.
Three additional roofs totaled 42,883 square feet and got two layers of polyisocyanurate with a facer and then the Kemperol system on top.
After rolling out a layer of resin, a polyester-based reinforcement is laid out and then saturated with another layer of resin. The material cures in as little as three hours allowing other trades to walk on it. The reinforcement rolls come in widths ranging from 4 to 41 inches, and all penetrations receive a custom cut scrim. After the construction crews are finished with a section, the surface receives a white coating.
“Aesthetics on this project are important everywhere, from the concrete to the trim to the roof. It’s all clean and white, glass and metal,” Calhoun said.
Terminations were very simple. Just waterproof right up to the deck, and it’s sealed for the night. A new chemical bond can be made by lightly sanding the existing surface and starting roofing again. This can be done even years after the first chemical bond takes place — a nice feature for repairs and maintenance.
The product is comprised of about 80 percent plant-based oils and has emissions that are low enough to be used indoors. Pedestrian areas will feature a quartz coating to improve traction. Florida Polytechnic will receive a 20-year No Dollar Limit Warranty from Kemper System.
“We worked with Kemper on the details all the way through conceptual to 100 percent contract documents,” said Jablon. “The envelope must be impervious to water. We feel very strongly about the Kemper product.”
“This is one of the most complex designs in geometry,” he continued. “This is special, and the workers know it’s special. It’s being built with a lot of heart and care.”