When to Use a Polishable Overlay

Brian Johnson of ACI Flooring Inc in Beaumont, Calif. shares his special process for polishable overlays
By Jim Peterson, president, The Concrete Network

Polished concrete has to be at the top of the popularity list of decorative concrete applications the last few years and it is still growing fiercely. This year at the World of Concrete it seemed that every other booth was selling polishing equipment in an effort to serve this booming market.

The majority of concrete slabs can be polished as can most existing slabs. Existing slabs often have imperfections such as tile grout lines, patch marks from framing braces or carpet tack strips, or even larger areas of the slab that have that have been torn out and replaced in making major plumbing repairs. Some customers like leaving the slab that way and polishing the concrete. It’s the look they are going for and it fits with a variety of design themes such as a skate shop, a hip clothing store, or the local fish taco eatery, for instance.

Other customers want polished concrete but without the underlying imperfections of the existing slab showing through. Brian Johnson, owner of ACI Flooring Inc in Beaumont California, has the perfect solution for those customers. “A polishable overlay will let us provide the polished concrete look for a client but without the underlying slab imperfections showing through.”

I recently spoke with Johnson about this option while he was putting the finishing touches on a project in Redlands, Calif. His company, ACI Flooring Inc, has been in business since 2003 and focuses on concrete flooring treatments such as polished overlays, microtoppings, stains, stampable overlays, and industrial epoxies.

His special process includes seeding the overlay then polishing to expose the aggregate. This creates the same look as though the original aggregate in the concrete was being exposed. The look can be very close to how terrazzo looks. “We don’t try to seed the overlay to make it look like terrazzo, we want it to look like ground concrete, yet this process can be offered as a terrazzo alternative at about half the price.” says Johnson.

Here is the sequence Johnson follows:

  • Demo existing flooring/ removing any glue or mastic
  • Grind the floor to a 2-3 concrete surface profile
  • Stitch any cracks in the floor
  • Apply an epoxy bond coat (standard or with moisture barrier if required)
  • Place the topping by pump, or directly from the mixing barrel
  • Seed the aggregate (it’s vital seeding be done at the right time)
  • Make any required or decorative saw cuts
  • After 24 hours, return to polish, dye, and densify
  • Apply a penetrating sealer

Johnson is frank in saying that the whole process has taken time to perfect. He notes, “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, and finally polishing the floor and applying dyes and the densifier. The process is not for the faint of heart or those inexperienced with the process.”

It’s all worth it in the end though. According to Johnson, “The customers, they love it!”

ACI Flooring Inc
Beaumont, CA

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