Fungal deterioration of building materials causes economic losses due to restoration processes and because it affects the health of the people exposed. Therefore, it is necessary to obtain highly deteriorating fungal strains to carry out studies focused on biodeterioration control. The aim of this research was to study the mycobiota involved in deterioration of facades through the isolation and characterization of fungal strains. In this sense, this paper characterizes the mycobiota that contributes to the deterioration of brick and concrete present in those places. Samples were taken from bricks and concrete with visible biodeterioration of the Cathedral of La Plata and the Experimental Station of the Centro de Investigación y Desarrollo en Tecnología de Pinturas. Relative density, apparition relative frequency, and ecological category of fungi isolates were determined. The deteriorating attributes were determined by carbonate dissolution test, pigment secretion assay, acid production test and brick weight variation. Cladosporium sp., Penicillium sp. and Aspergillus sp. were the taxa with the highest apparition relative frequency and abundance. Aspergillus niger MN371276, Lasiodiplodia theobromae MN371283, Cladosporium sphaerospermum MN371394, Penicillium commune MN371392 and Arthothelium spectabile MT071822 were the strains with the highest biodeteriorant activity. These strains can be used in studies on biodeterioration control of buildings materials.