Q. I have been contracted to remove a carpet tile floor and chemically stain the concrete below to provide a decorative finish. When we started removing the carpet tiles, we discovered that some of the adhesive is stuck to the floor. How can we remove the adhesive from the floor to allow the chemical stains to penetrate into the concrete?
A.Mike Miller, owner of the concretist, Benicia, Calif., provides this answer: “It's very difficult to remove adhesives and sealers from floors well enough to achieve good penetration with chemical stains. Start by using a good water rinse-able paint remover to remove as much of the adhesive as you can. Then sand, grind, or use diamond polishing equipment with low grit pads (50 to 100 grit) to remove some of the floor's surface, going below the region where adhesives can penetrate. You will probably expose some of the sand and aggregate in the concrete in this process.
“Another way to address the problem is to apply a skim coat or micro-top overlay cement over the entire surface and chemically stain that. You need to make the owner aware that the final appearance will look different with these two methods. You should show them a sample of each so that they can choose the look they prefer.”