Cleaning

Dirt stores moisture and pollutants and prevents the surface drying out. This is why it should always be removed. The following applies: as careful as possible, as intensive as necessary! As renders are generally painted, they should be cleaned with water and a detergent containing surfactants. Surfactants comprise hydrophilic (=water-friendly) and hydrophobic (=grease-friendly) constituents. Water insoluble dirt has an affinity to the hydrophobic part and are included in transport processes by the entire molecule.