Cinder block wall preparation first the cinder or concrete masonry unit block needs to be prepared correctly.
Tile over concrete block.
Apply commercially made filler that is made specifically for cinder or concrete blocks to create a smooth surface to which the tile can adhere.
Yet this application does make sense since concrete is heavy solid and is typically thought of as an unbending uncompromising material.
Before you begin to lay the tile over your concrete slab make sure the concrete is properly prepared.
Mix up a bucket of tsp tri sodium phosphate solution.
Tsp is a high strength cleaner which is useful for removing dirt grease and oil from your existing surface.