- Use a metal-bond diamond tool, like a 20/30 grit, to level out large differences in the surface or to remove any coatings on an older floor. If a floor does not have a lippage issue or coating, start with a 50/60 grit metal diamond or a 100/120 grit metal diamond. The first cut will obtain the look the building owner wants. The first cut is also used to open up the floor enough to absorb the densifier. If the floor is not opened up enough it will not be as hard wearing as it could be and its service life will decrease. If starting with a 50/60 grit metal diamond, use the 100/120 grit metal diamonds next to ensure the 50/60 scratch marks are reduced.
- It is usually a good idea to use a grout to fill in the air pockets, pin-holes and hairline cracks created when grinding. Grouts result in a much cleaner floor with better clarity. Acrylic-based grouts are very easy to use and are applied during the last stage of metal-bond diamond grinding. To apply, spray a little water to dampen the floor and then pour the grout on and “broom in” (the broom will clean out the dust in the pores). While the acrylic-based grout is still wet, grind over the surface with a grinder using 100/120 grit metal diamonds. This creates a slurry and fills the pores. Next, use a foam squeegee to clean the floor. Do not use a broom or vacuum as this may remove some of the grout in the pores.
- It is a good idea to densify the floor at this point. The densifier will harden the cement and grout, so the grout will not fall out when grinding. Hybrid diamonds, such as ceramics, can be used after the densifier has completely dried. These hybrid diamonds are more aggressive than resins and help beginner operators remove random scratching that may have been left by the metal-bond diamonds. 100-grit hybrids should be followed by 200-grit hybrids. These grits are honing the concrete and should eliminate all visible scratches.
- Next, polish with 400-grit resin abrasives. This might be the last step depending on gloss specifications. If needed, 800-grit resin pads can be used to achieve further gloss and clarity on the floor. The 400-grit resin closes the floor enough to be a polished surface and still maintain a good slip coefficient for the commercial/industrial environment.
- The final step is applying a guard to the finished floor. A guard is usually a better option for a high traffic area than a topical sealer. The major difference is that a guard penetrates into the concrete and only leaves a residue on the surface. When the concrete is fully cured, the guard is buffed off and the concrete is then a wear surface. A sealer is topical and usually needs to be heated with a high speed burnisher to cure. While both will protect the floor, the sealer will eventually wear away and need maintenance in high-traffic areas.
Department stores and warehouses are always looking for new, cost-efficient and “greener” ways to enhance their facilities. Knowing the basics of industrial/commercial polishing can allow you to offer these facilities another flooring option with endless possibilities.