Any base to be coated with ceramic coating (floor/wall), must be free of loose particles, dust, sludge, paint, greases and oils, waterproofing, and others. These types of finishes or dirt form a film preventing the mortar from adhering and anchoring to the laying base.

 

With time, the detachments also appear. Then, for a quality laying, completely remove the finish or make a new laying base.

 

In waterproofed environments such as slabs, mechanical protection must be made (cement and sand layer of at least 2 cm).

 

A good laying consists of the total adherence of the ceramic tile on the laying base, so only scratching or perforating the base will compromise the adhesion.