Effects of surface roughness on adhesion between epoxy resin floor coatings and cement mortar substrate were discussed. First surface roughness and waviness of various cement mortar substrate which were abraded through various abrasive papers were measured. Second, peel energy was measured. In stead of cement mortar substrate, the gypsum replicas were used in the measurement for avoiding an influence of wide variety of surface free energy of cement mortar substrate. The peel energy between the gypsum replicas and epoxy resin floor coatings was discussed. It was found out that peel energy closely related to the surface roughness of substrate, and an increase of surface roughness was effective in improving adhesion between the substrate and the coatings.
