Can I apply microcement on an epoxy floor?

Epoxy is non-absorbent and smooth, so it must be mechanically roughened and degreased. Without an adhesion bridge or a sandblasted surface, the adhesion would be unacceptably risky. It is therefore not only about what material the substrate is made of, but primarily about its condition. Before application, check for strength, flatness, grease, dust, cracks and any movement. If the surface is risky, it is better to reinforce it or first carry out a test area.