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Office Space For this 14,700 square-foot (1,366 m²) roof, the crew used a system that wouldn't have "tobacco juicing," which is when the asphalt bleeds through the white coating — something that confuses many clients. JOB AT A GLANCE PROJECT: Re-roofing an office building in Southern California with a white elastomeric roof coating system COATINGS CONTRACTOR: used a Graco gas-powered hydraulic sprayer and Roofmaster safety barriers. One challenge in the spraying was the number of roof penetrations the crew needed to work around. But because they were spraying the coating (as opposed to installing a membrane roof or using another application method), they were able to get into those hard-to-reach places. "If you were to install a membrane roof, it would be a lot more labor intensive," Mulligan said. Ewart agreed that the fuid-applied roof system was easy to install. "We power-wash the roof, perform required repairs throughout, reinforce the drains, correct areas of standing water, and then begin the application," he said. Te crew put down PG800 asphalt emulsion with a layer of polyester fabric embedded into it. Two top coats of Polyglass PG700 were then spray-applied over the basecoat and then topped of with fnishing coats of PG700. Te crew used 4 gallons per 100 square feet (15 L/9 m2) emulsion and 3 gallons per 100 square feet (11 L/9 m2) PG700. Each coat was sprayed in one pass, and took 24–48 hours to cure. Allied Roofing Company 3855 S. Main St. Santa Ana, CA 92707 (714) 542-1100 www.alliedroofingcompany.com SIZE OF CONTRACTOR: 18–25 people SIZE OF CREW: 6 crew members PRIME CLIENT: Office building for a client in Cerritos, Calif., that wishes to remain unnamed SUBSTRATE: Built-up roof (BUR) cap sheet roof system CONDITION OF SUBSTRATE: Aging, in poor condition with water intrusion throughout SIZE OF JOB: 14,700 square feet (1,366 m²) DURATION: 5 working days The six-man crew from Allied Roofing Company started by applying the asphalt emulsion with a gas-powered hydraulic sprayer and then embedded a layer of polyester fabric into the wet coating. UNUSUAL FACTORS/CHALLENGES: » Water leakage from roof intrusions during power washing prep » Roof penetrations possible to fix with spray-application » Conditions could be windy but that didn't become a serious problem MATERIALS/PROCESSES: » Performed roof repairs/maintenance throughout, including torch-applied membranes in the roof drain locations » Spray-applied PG800 asphalt emulsion with a layer of polyester fabric embedded into it » Spray-applied two top coats of Polyglass PG700 over the basecoat/ polyester, using 4 gallons per 100 square feet (15 L/9 m²) emulsion and 3 gallons per 100 square feet (11 L/9 m²) PG700; each coat was sprayed in one pass, and took 24–48 hours to cure SAFETY CONSIDERATIONS: » Wore eye protection for all phases » Parapet walls were 4-feet (1 m) tall, so no fall protection was required COATINGSPRO JANUARY 2014 61