Polished Concrete
Probably the most misunderstood of today’s popular flooring options is polished concrete. Brad Burns, executive director of the Stevensville, Md.-based Concrete Polishing Association of America, says his four-year-old organization was established to be an advocate for specifications, education and standardized procedures for the polished concrete industry.
“There wasn’t really any other agency that we felt was qualified to lead contractors in the industry,” he says. “Polished concrete is very unique—it’s concrete but it’s flooring and it can be decorative, not necessarily janitorial and not always new construction. We wanted an organization that knew the ins and outs of polished concrete to lead the industry.”
Burns says there are misconceptions surrounding the product, which has only been around for 15 years, and its polishing procedures. In new and retrofit applications, the building’s concrete slab is systematically polished with heavy grinders. Through a series of abrasions with diamond tools—70 grip metal bonds to 3,000 grip resins—a sheen is created in the floor. “In layman’s terms, it’s a granite countertop for your floors,” Burns explains. “A granite countertop is a rock from a mountain that is cut and polished with diamond tooling. We’re doing essentially the same thing with an existing slab for a floor.”
The procedure becomes complex because there can be major variables in concrete’s characteristics. “Concrete is very regional in mix design, environmental curing, and placement and finishing processes,” Burns says. “There’s such a huge variety in the matrix that we’re polishing, the contractor has to understand the polishing process to adapt to those variables.”
During the polishing process, color can be added to the slab. “The contractor avoids refining the concrete to a point where the color won’t penetrate,” Burns notes. “Typically color is applied by a water- or solvent-based dye. It’s a very small crystal that’s soluble into a liquid— acetone or water. You put it into the concrete, and as the water or acetone evaporates out, the color stays.”
If a building owner decides to change the color of his or her concrete floor, a light color can be re-dyed to a darker shade, but darker colors often have to be re-ground and re-polished before changing the slab to a lighter shade. Burns says polished concrete is very popular in retrofit applications because it makes use of the existing substrate, requires little maintenance and creates a floor that never needs to be replaced. “In heavy-traffic areas, you have to be more on top of keeping the floor clean and you may have to restore or refurbish it every three to five years,” he notes.
In addition, polished concrete is highly reflective. “In most cases, you get about a 20 to 30 percent light increase in the room simply because of the polished concrete flooring,” Burns adds.
Although this is only a glance at the many flooring options available for retrofitting floors in commercial buildings, it provides an overview of the strides the flooring industry is making in ensuring its products meet the needs of today’s building owners and occupants.