Impact of Water-Repellent Products on the Moisture Transport Properties and Mould Susceptibility of External Thermal Insulation Composite Systems

External Thermal Insulation Composite Systems (ETICS) are constructive solutions widely used to increase the thermal insulation in new and retrofitted buildings. However, these systems can present several anomalies due their constant exposure weathering agents anthropic factors. Water is generally major cause of degradation. Thus, application water-repellent products minimize appearance durability systems. In this paper, acrylic-based siloxane-based hydrophobic were applied ETICS, with aim assessing compatibility, effectiveness, products. The moisture transport properties mould susceptibility assessed through laboratory tests on untreated treated specimens. treatments was also evaluated artificial aging (heat-cold freeze-thaw cycles). Results show that protection decreased water absorption, slightly drying rate, presented adequate vapor permeability. After aging, still had reasonable effectiveness and, one exception, improved diffusion Additionally, ETICS underwent an alteration finishing coat (possible modification porosity) cycles. No clear linear correlation found between contact angle values absorption results, evidencing influence other factors related composition