An assessment of façade coatings against colonisation by aerial algae and cyanobacteria

An accelerated water-streaming test method was used to evaluate several types of façade coatings regarding their behaviour to colonisation by algae and cyanobacteria, by closely reproducing the phenomenon of natural biological soiling. A set of materials with defined physical characteristics was thus investigated vs. the colonisation by algal and cyanobacterial strains isolated from natural façade biofilms. Porosity and roughness of the materials showed to be factors of influence in the establishment of those micro-organisms.