Ocorrência de manchas em fachadas após serviços de manutenção: origem, causa, fenômeno e mecanismos associados

Abstract

The appearance of stains on building facades is a common problem in urban environments, which can be caused by various factors including weather conditions, air pollutants, biological agents, and associated with material failures or construction methods, or resulting from poor or insufficient maintenance services. These stains not only affect the aesthetics of facades but may also indicate deeper issues such as infiltrations, material deterioration, and compromise of structural integrity. This study consists of a multidisciplinary investigation through case studies, aiming to identify the possible origins, causes, and associated phenomena of the pathological manifestation: stains observed after facade maintenance. The case study was conducted in three residential buildings, two located in Jaboatão dos Guararapes, near the coast of Piedade and Candeias, and one in Cabo de Santo Agostinho, near the beachfront of Paiva. The purpose of the study was to analyze the appearance of stains on facades, particularly in the grout regions, extending to ceramic coatings. Visual inspections of the site, analysis of the execution method adopted in the service, damage mapping, interviews with maintenance teams, evaluations of materials used were conducted to diagnose the problem. The results indicated that the local atmospheric factor, namely the saline mist of the region, and the material used in the grout production, were decisive factors in causing the appearance of stains. In the service execution, a polymeric material was incorporated into the grout to enhance its adhesion, replacing a traditionally used product (emulsion of an acrylic copolymer) with a newly launched product (acrylic-based polymeric adhesive), which likely contributed to the appearance of white stains on the facades of the highlighted buildings. The eastern façade region was the most affected, likely indicating the influence of saline mist carried by the wind, with its deposits embedded in the grout material, which was destabilized by the action of water.