How to Repair Substrate Irregularities?

Irregularities should be repaired prior to applying the microcement, not with the microcement itself. For floors, use high-quality levelling or repair compounds with sufficient strength, ideally at least 30 MPa in compression. Flexible adhesive used for general floor repairs is not advisable – it tends to be softer and can cause problems. The compound should have a minimum compressive strength of 30 MPa. Avoid using flexible adhesives for floor repairs.