Just in time for the holiday season, the Best Buy in Rockford, Illinois, found itself with a most unpleasant development: a leaky roof. With shoppers ready to hit the store, these leaks threatened to send potential customers running for cover.
Although the Firestone single-ply roof was nearing the end of its warranty, Firestone officials wanted to get the final few years out of it rather than tear it off. In some respects, this made the job easier, since long-term durability was less of a consideration. But it still presented a daunting challenge to maintain a roof that already had previously patched leaks and was not in great shape. In addition, the onset of frigid winter months meant that solutions had to come fast, since many coatings cannot be applied in freezing temperatures.
Fortunately for Best Buy and the site’s property management, the team at regional coatings contractor GreenPROChicago rushed to the store with the speed of a savvy Black Friday shopper and offered a multi-faceted solution.
Quick Fix to Survive Winter
The entire 40,000-square-foot (3,716 m2) roof needed to be recoated, and the three-person team from GreenPROChicago believed the UNIFLEX white coating system to be an optimal choice.
Unfortunately for them, David Welte, president of GreenPROChicago, knew it would take at least three weeks to complete the entire roof — and with winter bearing down, they didn’t have that long.
“For that product, it has to be applied at no less than 40 degrees Fahrenheit [4.4° C],” Welte said. “Once you start getting too close to freezing, the molecules in the coating freeze and don’t cure properly. You’d have to redo it.”
With that in mind, GreenPROChicago’s team made the unconventional choice to do only part of the job in the fall before taking a hiatus over the winter.
“That fall, we started the process by doing all the seams and spots where they were having leaks,” Welte explained. “Basically, we were patching it to get them through the winter. Then we picked it up again in spring. It was unusual, but that’s the best way we could make it work.”
Safety was a primary consideration, and before starting any work
within 6 feet (1.8 m) of the edge, crew members put on Guardian’s fall protection harnesses. Workers were tethered to heating, ventilation, and air conditioning (HVAC) units if using fall protection. The crew didn’t need much more in the way of safety equipment.
“The benefit of this system is that it is water-based, has no VOCs [volatile organic compounds], no fire dangers, no adverse effect on business, and is LEED [Leadership in Energy and Environmental Design] compliant,” Welte explained. “Rollers and buckets are all that is needed to create a renewable and sustainable roof.”
The abbreviated fall project took three days. With a dirty roof to start, cleaning was the priority on day one. The crew scrubbed areas with brooms and Simple Green, an environmentally safe cleaner and degreaser. From there, a Mi-T-M Job Pro pressure washer was used to rinse everything.
On the second day, the team applied the UNIFLEX SPE Gray Acrylic Base Coat from 5-gal (18.9 L) buckets. They used 9-in (22.9 cm) rollers and 4-in (10.2 cm) brushes at a rate of 1.5 gal (5.7 L) per 100 square feet (9.3 m2), targeting a thickness of 30 mils (762.0 microns) wet film thickness (WFT). They chose gray for the basecoat to help show the crew where insufficient white topcoat was applied, Welte explained.
The crew applied the basecoat to leaking curbs, seams, and any areas needing reinforcement near drains or HVAC units. They used UNIFLEX’s 3-Course Method, which consisted of an initial elastomeric acrylic, followed by embedding polyester fabric cut to the appropriate size, and then applying another layer of basecoat on top of the fabric. The crew allowed that system to cure overnight.
On the third day, the crew applied 30 mils (762.0 microns) WFT of the UNIFLEX Premium Elastomeric White Top Coating. If the crew needed the roof to last longer, they might have applied a thicker topcoat, but the short-term warranty made a thinner coat sufficient.
“All you’re really doing is buying time,” Welte explained. “Each year, the sun chips away at the coat, usually at about 1 mil [25.4 microns] per year. So you’re wondering how many years it lasts until it gets to the basecoat. It’s all about how much thickness you put into it — but since we didn’t have a long warranty, we just put on the one wet coat at 30 mils [762.0 microns], and let it dry.”
From there, the crew retreated into hibernation for another Illinois winter.
Major Spring Cleaning
As the weather warmed and Welte’s crew returned to the jobsite, the application specifics were familiar. The difference, of course, was the scope. While the process and materials used were similar, coating the entire roof was a much more time-consuming task, relative to the “patching” done a few months earlier.
For example, power washing took three days instead of one, and it required two Mi-T-M Job Pro pressure washers. And the effects were much more noticeable, given the larger scale. “It was dark gray, but it turned out to be white after the washing,” Welte said.
From there, the team took two days to apply the basecoat system to all curbs, penetrations, pipes, seams, and corners that were not leaking in the fall and thus went unattended to. With smaller items done, Welte’s crew finally went to work on coating the entire roof. Although the desired thickness remained the same, the crew used rollers twice the size for better coverage. They also used a mil gage to ensure the desired specifications were reached.
The roof was coated in sections, with the entire process taking about four days for the application of the basecoat and about four more working days to complete the topcoat.
For the roof as a whole, one finishing touch still remained. To reduce wear from foot traffic by HVAC service providers, the crew added special walkways from the hatch to all HVAC units, consisting of a gray coating and embedded 40-in (101.6-cm) rolls of fabric, with extra silica added for grit. Rather than the water-borne elastomeric, they used a solvent version of the coating in contrasting gray to make it clear where workers should walk.
“It’s not as slick as a regular roof would be,” Welte said.
With the addition of the walkways, Welte’s team could finally enjoy the successful conclusion of the job. Three weeks after phase two began and months after the initial fall patching, their unusual phased process came to a close.
“They were very happy with the results,” Welte said. “I was communicating through Firestone’s warranty department, and they followed up with me and said the customer was very pleased. They didn’t have any more leaks.”
Expert service, indeed!