Microbial Deterioration of Clay Roofing Tiles as a Function of the Firing Temperature

This study illustrates the genesis and growth of the biofilm, known as patina, on the surface of clay roofing tiles after the action of a single fungus species, Aspergillus niger, (90 days) as the main cause of their aging processes. The nanocrystalline products, formed due to the fungus hyphen penetration into the ceramic support, contributed to the formation of an abundant reactive surface area of the existing and newly formed pores, intensifying the aging processes of the clay roofing tiles. The destruction of the ceramic supports, laboratory samples (920°, 995°, and 1055°C), and industrially obtained one (1100°C) was studied as a direct function of their microstructural and pore characteristics. A relationship among the textural characteristics of the studied ceramic segments of the defined microstructure, the tile surface roughness values, and the formation of the biofilm, which was developed after the action of the fungus, was set up.