Careful preparation of the substrate is the most important factor for successful painting. Even if the preparation of the substrate requires much more time than the painting itself, it is worth the effort. For successful painting, the substrate should be clean, free of grease, rust, rot, without crumbling and firm.

If the old coating has deteriorated so that it has cracked or is mostly peeling off the substrate, it needs to be completely removed. Removal is performed in several ways, depending on the type of coating and substrate: mechanical, chemical or heat.

Resting of paint in the packaging usually leads to partial separation of the paint and the appearance of “liquid” on top. The paint should be mixed with a stick, until achieving a uniform mixture.

The optimal temperature for applying the paint is usually around 25 ± 5^oC, at a relative humidity of around 65%. Solvent-based paints can be applied at lower temperatures but with slower drying. However, depending on the coating you apply, it is important to follow the manufacturer’s instructions.

Proper choice of tools facilitates painting. The brush is used for smaller surfaces, door and window frames, for wall corners and joints of walls and ceilings. The roller is used for large areas. In many cases, the paint can be applied with a gun, but the manufacturer’s specifications on the possibility of applying a specific colour should be followed.

Efflorescence is the appearance of white crystals or deposits on mortar, plaster or brick. Efflorescence increases in the presence of moisture. No paint should be applied to such substrate. The deposits should be removed and if they do not return within 14 days, the substrate may be painted. If re- efflorescence occurs, the surface should be sanded and moisture removed.