The substrate should be solid, firm, and free from hollowing, with a tensile strength of not less than 0.4 MPa. When the substrate's tensile strength is less than 0.4 MPa, reinforcement should be performed. When tiling ceramic finish tiles on aerated concrete, lightweight wall panels, wall insulation systems, etc., measures should be taken to ensure bonding quality. The surface flatness deviation of the base should not exceed 3mm, and the verticality deviation of the facade should not exceed 4mm.