When Shawn Halverson, president of Surfacing Solutions, Inc., took over 9,000 square feet of concrete polishing, part of an expansion project at San Diego Miramar College, he was met with several challenges. The architect had originally specified polished floors without color and with little to no aggregate exposure. After his crew took its first pass on the floor with 80-grit metal bond abrasives, he found out why the previous two concrete polishers backed out of the project.
“The concrete wasn’t what you would normally polish,” Shawn Halverson says. “But with our experience, we were able to troubleshoot the issues and produce a quality floor.”
Halverson’s experience in the concrete industry started with his involvement in a structural concrete company. In 1999, he opened Surfacing Solutions, Temecula, Calif., as a full-service decorative concrete firm working both residential and commercial jobs. Over the years the company has shifted its focus into the commercial market, today performing about 90 percent of its jobs in the commercial realm.
Halverson and his crew has been polishing concrete for seven years. “The polishing industry has matured, with manufacturers coming out with better products and better equipment,” he says. “That has made the work much easier and contributed to a better end project.”
The ups and downs of concrete
Coming in on the tail end of the project, Halverson bid the job at Miramar College on paper before seeing the concrete. He says while he prefers getting involved in a job early enough to hold a prepour meeting with the general contractor and concrete contractor pouring the slab, that only happens on about half his jobs. The main challenge with the floors at Miramar College, which were spread out in seven different locations throughout three buildings on campus, was they were not flat. Halverson says there was up to a ¼-inch variation throughout the floors and the 80-grit metal abrasives, a typical starting point on new floors, were just taking off the high points. “We had to start our cut with 40-grit metal-bond abrasives, which allowed us to take out both the peaks and the valleys,” he explains.
Getting the general contractor and owner to agree to this extra processing step wasn’t easy. The cost to perform this flattening pass, in both the north-south and east-west directions, would be hefty. Halverson needed them to agree to cover the expense. “I explained to them that a wavy floor produces a scattered light reflection pattern, while a flatter floor offers a more orderly light reflection pattern,” he says. Because the new buildings at Miramar College contain a lot of windows to take advantage of natural lighting, it was a critical point for him to convey in order for his floors to look their best at the end of the project.
Halverson cut a deal with the architect, concrete contractor and general contractor. If they liked the results of the 40-grit pass, they would pay the extra cost for the step. If they were not impressed, Halverson would not get paid for that portion of the job. In the end, the group had to agree — they could not deny the improvement. “We were able to recover the clarity of reflection,” Halverson says.
Once the success of the 40-grit pass was established, the Surfacing Solutions crew proceeded with the project, processing the concrete in two classrooms, two mezzanines and two lobbies. After completing the 40-grit metal-bond abrasive pass, the crew proceeded through the concrete processing steps with 80-grit metals. Then the crew dropped back to 50-grit resin-bonded abrasives before proceeding with 100-grit resins, 200-grit resins and 400-grit resins.
The architect had originally requested a 1,500-grit polish, the level he thought the contractor would need to polish to in order to achieve the level of shine he was looking for. But Halverson stopped the job after the 400-grit abrasives, having achieved the architect’s desired level of shine at that point. Stopping the job after the 400-grit abrasives also saved the owner money by cutting out about 120 hours of labor.