Recently, however, the normally bright white, 130,000-square-foot roof was dulling as a result of dirt, mildew and other airborne pollutants that were embedding in the roof, to the point that the outline of the roof’s concrete deck pattern was telegraphing through.

To help solve the problem, university officials brought in Patrick L. Downey, a veteran of over 25 years in the roofing industry and president of Merik, Inc., a roofing consulting service based in Marietta, Ga.

According to Downey, the principal problem was a breakdown of the existing acrylic coating, along with dirt and mildew build up and some minor chalking. There was also damage to flashing systems and the lightning protection system that needed repair.

When it came to the selection of a coating system for the roof restoration, Downey said the primary concern was a desire for a longer service life. The acrylic coatings that had been applied during previous restorations were expected to last five to seven years, but began deteriorating after only two to three years.

“Good compatibility between the new coating and the existing coating was also important,” he said. “Thus, as part of our due diligence, we conducted adhesion tests on the roof using a number of coatings that incorporated new water-based technology. We also wanted a coating that was user friendly for the installer and an application process that wouldn’t interfere with the operation of the facility.”

Selected for use as the topcoat on the coliseum roof was ReflectiClean™ from ER Systems Inc., a single component, waterborne elastomeric coating that provides excellent color retention and fade resistance as well as a 15-year warranty.

Available in eleven standard colors plus custom color matching, the new coating is based on Kynar Aquatec®, a new emulsion-based, low-VOC PVDF fluoropolymer technology developed by Arkema Inc. to deliver the same durability and performance as Kynar 500 PVDF resin-based coatings.

However, rather than requiring high temperature factory baking, coatings based on Kynar Aquatec® cure at ambient temperatures, meaning they can be field applied to a variety of substrates, including metal, PVC, SPF, concrete and wood, and as a finish coat over acrylic basecoats.

“This was our first experience with this coating, and we definitely found it to be an acceptable option for future work,” Downey said. “We would have no hesitation using it again, especially in projects that require a high end coating system.”

M. Jordan Roofing, a commercial, industrial and institutional roofing contractor located in Manchester, Ga, performed restoration of the roof. According to Brad Jordan, Jordan Roofing’s project manager on the coliseum job, the roof restoration involved a number of stages.

“We pressure washed the entire roof first,” Jordan said. “Once that was done, we could see which flashings required repair. We also removed areas of old roof coating

that had delaminated and filled them by embedding a fabric and covering them with an acrylic coating.”

Next, the entire roof was covered with a nine-mil dry thickness of an acrylic coating. The acrylic coating was then covered with two coats of the ReflectiClean ™ finish coat. Applied at the rate of one half gallon per 100 square feet, the finish coats totaled seven mils in thickness.

Jordan reported that this was his first major use of the new topcoat. “We had applied the coating before, but only in small areas and primarily over painted metal roofs,” he said. “This is the first time we applied it onto such a large area.”

While he noted that this was his first experience with the coating, it probably will not be his last. “From an applicator’s point of view, I would use this coating again and recommend it because it was so easy to work with,” Jordan said.

“It mixed well and sprayed well. Plus, there were no problems with viscosity or color matching. It was very consistent.” He also noted that while the job was not overly difficult, there was an unexpected challenge. “As our crew was applying the new topcoat, the roof surface was so bright, they had to wear sunglasses just to see where they had applied the coating,” he said. “And, not just normal sunglasses, but those with polarized lenses.

That’s how bright the surface was.”

While the roof’s surface brightness presented a minor challenge to the roofing contractor, it was a major benefit to the roofing consultant. Downey notes that because the coliseum was constructed during the sixties, it has minimal insulation. As a result, heat reflectivity of the roof’s surface was another important aspect of the project.

“The fact that the new coating is a harder film and more resistant to dirt build-up and mildew will help with the roof’s long-term heat reflection, which is important to the ongoing operation of the building,” Downey said. “So while the roof of the building does look great aesthetically, it also exhibits a great deal of functionality in terms of its heat reflectivity and cool roof properties.”

And, this was not a matter overlooked by the school, because as Downey pointed out, “The University of Georgia is actively involved incool roof and other sustainability issues, not only with the coliseum, but with other structures throughout its campus.”

http://www.mjordanroofing.com