POLISHED CONCRETE OVERLAYS OFFER A FAST SOLUTION TO PROBLEM FLOORS

Source:www.stonediamondtool.com Date:2021/8/9 Read:192

Learn how contractors are taking advantage of this growing market niche for polished concreteBy Anne Balogh, ConcreteNetwork.com columnist

Why floor owners like polished overlays

In most cases, polished overlays are used to cover up problem floors and achieve a perfectly smooth, seam-free surface. In other cases, the owner wants to enhance an existing floor with decorative sawcuts or get a terrazzo-like finish by seeding the overlay with colored aggregate.

“A polishable overlay will let us provide the polished concrete look for a client but without the underlying slab imperfections showing through,” says Brian Johnson, owner of Extreme Measures Construction, Beaumont, Calif., a company that installs polished overlays, microtoppings and stampable overlays. One of their specialties is to seed the overlay and then polish it to expose the aggregate. He says this process can be offered as a terrazzo alternative at about half the price.

Youri Semakov of Concrete Polishing & Sealing Ltd., Ottawa, Ontario, says that many of his customers appreciate the fast turnaround time of a polished overlay when compared with replacing or patching the existing concrete. “The microtopping can be successfully installed over any hard surface including concrete, terrazzo and tiles, with a fast turnaround time of just 24 hours,” he says. A polished microtopping has many other attributes as well, he adds. “It can easily be treated with color or a decorative coating, it is environmentally friendly, mold and mildew resistant and, most important, economical.”

Tom Zilian of Madstone LLC, Barrington, R.I., installs polished overlays for both commercial and residential clients. “The demand is growing as awareness grows, especially in the residential and small high-end commercial markets,” he says. His clients include image-based businesses who are trying to portray an ultramodern, minimalist design aesthetic and homeowners who like polished overlays because they can be custom matched to a desired color and offer a seamless, low-maintenance surface. “Most importantly, polished overlays are a good solution when the existing concrete is in such poor condition (cracks, spalling, pitted, out of level) that polishing the existing concrete would look undesirable and too industrial,” he says.

Installation considerations

Installing a polished overlay requires a different level of expertise than when simply polishing an existing concrete floor. Preparing the floor for the overlay is often the most time-consuming aspect of the process, especially if existing floor coverings must be removed and the underlying floor needs to be reprofiled. Semakov often uses a 10-inch sandblaster and industrial floor grinder to remove residual tile mastic and unsound concrete and leave behind a roughened surface profile.

Placing the overlay itself can also be tricky. It’s not for the faint of heart or those inexperienced with the process, according to Johnson. “Timing is critical on so many parts of this process, such as getting the mix on the floor, seeding the mix at the right time, sawcutting [if desired], and finally polishing the floor and applying dyes and the densifier,” he explains.

Zilian agrees, and says that polishing a concrete overlay requires more coordination of efforts and attention to detail than polishing a conventional concrete slab, so it’s important to be ready for any contingency. “Timing is everything,” he says. “We use lots of manpower and two or three mixing stations to make sure a fresh batch is continuously being delivered to the pour line. We also have a high degree of expertise behind the gauge rake and smoother.”

Once the overlay is down, however, the polishing process is fairly straightforward and can be accomplished with standard concrete polishing equipment. “For overlays, we use the same method as when polishing normal concrete, the same diamond tooling,” says Semakov.

Zilian advises contractors to always use a planetary grinder when polishing concrete overlays and begin polishing no later than 24 hours after overlay placement.