Evaluating the effectiveness of self-cleaning products applied on external thermal insulation composite systems (ETICS)

External thermal insulation composite systems (ETICS) have been extensively applied on building façades with the aim of implementing the thermal and aesthetical properties of the building envelope. However, the formation of stains and deposition of particulate matter is often observed in the surface of these systems. The use of multifunctional products with self-cleaning properties can reduce surface anomalies and thus enhance the durability of ETICS. This study aims at evaluating the effectiveness of three protective coatings with self-cleaning additives (i.e., TiO₂ nanoparticles), when applied on the surface of ETICS. Three different stains (rhodamine, methylene blue and silver paint aerosol) were applied on the ETICS finishing coat, evaluating the removal of these stains after exposure to natural (solar radiation) light source. The surface properties (compactness, hardness, roughness, gloss, and color) of the ETICS were evaluated prior and after sun exposure. Results showed that the application of the three products lead to a modification of the surface properties (compactness, hardness, gloss, roughness) of the ETICS specimens, and sensibly enhance the self-cleaning, hydrophobic and aesthetical properties of the ETICS.