If you look carefully you will see something that there is a cement like material between each tile that is called grout, it fills in the gap between the tiles. We have to seal this off and we use an epoxy to do so. Epoxy is a plastic-like material that, once cured, will become as hard as rock. The epoxy also helps prevent the thin microfinish overlay from sinking into the grout lines and creating a shadow of the tiles in the finished floor. It also prevents moisture from coming up through the concrete slab and into the concrete overlay.
After all that prep we laid down a skim coat overlay layer. In a microfinish concrete project like this one, a skim coat acts as a bond coat between the upper microfinish layer and the layer beneath it. The skim coat completely covered the tile, as shown in the third photo but it is thin enough that some “ghosting” of the tiles is still visible. The epoxy we’d placed inside the grout lines had filled in most of the lines but not all of them. Without the epoxy, however, the ghosting would have been more prominent.
Next, we laid down a layer of microfinish overlay. This layer filled in the ghost images of tiles, creating a smooth surface. To wrap it up we added a color stain that complemented the new kitchen countertop to the new concrete overlay over tile and sealed it with a high gloss polyurethane. The finished kitchen floor was a virtually unnoticeable 1/8″ taller than the section of tile adjacent to it and the homeowner was ecstatic about his new stained concrete floor.