For 35 years, the custom woodworking occupant at a building in Raleigh, N.C., had experienced leaks from his roof. “He does absolutely phenomenal work but had had a leak constantly for 35 years. He’d just learned to live with it, but we were able to fix it,” said Fred Wolfe. Although Wolfe now acts as principal consultant for 5 Prime Coatings, at the time of the project he led the two-person coatings crew from Roof Control Services.
Thirty-five years is a long time to live with a leaky roof, and it wasn’t because the building owner, Empire Properties, hadn’t tried to get it fixed. Nothing else seemed to stick. It was high time the problems were fixed — for good!
Clean and Coat
The solution for this project was a one-coat silicone-based material. That material was to be GE’s Enduris 3500 Roof Coating, but first, the crew needed to prep the rooftop.
Gaining access via a ladder outside, the crew started with cleaning the 2,500-square-foot (232.3 m²) roof with a powder cleaner mixed with water. They sprayed that to the roof and scrubbed it in. Then, they used a pressure washer by Generac to clean the rest of the dirt and chalking and to help open up the thermoplastic olefin (TPO) surface. That process helped the crew give the roof substrate a micro surface profile and “give us something to stick to,” Wolfe said. It took them about a day to complete that stage, and the next day they came in to start on the repairs.
Using BASF’s MasterSeal NP 1 urethane caulk, they sealed any open seams and filled in missing grout. They also fixed any rusting around the skylights by sanding the metal and applied Sherwin-Williams’ DURA-PLATE 301L/K epoxy.
The crew coated the rooftop, including the parapet’s brick walls, in two days. “We basically made a bathtub where no water could leak into the interior walls through the roof,” Wolfe explained.
“We did an adhesion test and found out we didn’t need a primer; it passed with flying colors,” he explained. “We were confident we didn’t need a primer.”
With the roof ready, they applied an average of 50 mils (1,270.0 microns) of the silicone coating to the flat area, which Wolfe called field coating, and, because these were vertical surfaces, they applied an average of 32 mils (812.8 microns) up the parapet walls.
Despite the parapet, the crew still needed to wear fall protection; the walls weren’t tall enough to protect the crew from at-height dangers. Therefore, they roped off the perimeter and wore AES Raptor harnesses by Leading Edge Safety. They also wore hard hats, safety vests, steel-toed boots, and gloves.
The coatings were applied using rollers with 3/8th-inch (9.5 mm) nap of microfiber. They use rollers from Linzer because they don’t release the tufts of lint that “cheaper” versions leave in the coating. Leftover lint creates a “mottled surface,” according to Wolfe, and that wasn’t acceptable. “I am pretty particular,” he continued.
Within about four hours, the coating skimmed over. In general, that helps because this particular coating is hydro-cured, which, according to Wolfe, “means that all that requires is the water from the air to make a chemical reaction to make the coating cure.” He noted that heat can speed up the process, but another kind of weather was what worried them on this project: thunderstorms.
Because they already had to contend with dew in the mornings, which meant waiting until about 10 a.m. to start work, potential rain in the afternoons made the workdays even shorter. Sometimes the crew only had a few hours to work each day! “But this project was so small that we knocked it out pretty quickly,” Wolfe said. After about 24 hours, the coating was completely cured, and the crew was able to dispose of any leftover buckets of cured coatings and used rollers. With no spray guns, there were no spray lines to clean on this job.
Safety and Sauce
One aspect the crew paid particular attention to when choosing the coating on this job was associated odors. With a well-known barbecue restaurant next door to the jobsite, affecting the patrons was a concern for this client. Smelly coatings and barbecue sauce just don’t mix! According to Wolfe, he “assured them that it wouldn’t happen.” Because they used a coating with high solids and no solvents, there was “almost no smell; you’d think you were smelling interior latex paint,” he said.
Another particular point for this crew was offering the client a safety walk pad up top. “The walk pad is pretty unique in the roofing industry,” Wolfe explained of the yellow walkway around the heating, ventilation, and air conditioning (HVAC) units and sky lights. On top of the layer of white silicone that the crew applied to the entire rooftop, they also applied a layer of the same coating in a safety yellow color in the areas designated for the walkways. They applied this layer at approximately 80 mils (2,032.0 microns) with sand broadcast to rejection into the coating for extra anti-slip qualities. Although the application method is proprietary, unlike other methods where the yellow lines blur into the white rooftop, this crew gave the client completely straight, crisp safety lines. “That’s something that we came up with as kind of a bonus,” Wolfe said.
“The reason that I love roof coatings for building owners is that coatings find leaks,” Wolfe explained. “Any time there is a hairline or pinhole — some stubborn leak — that’s when these systems shine. The coating finds the leak.”
For the wood worker who’d been dealing with a rainy roof for 35 years, having a system that could find and fix the leak was ideal. It took a total of three days for Wolfe and the Roof Control Services crew to complete the project from start to finish, but they were able to leave the client with a great solution. As Wolfe said, “at the end of the day, he’s leak free. That’s the success of this story.”