Inspection and Diagnosis of Bond Strength Loss in Ceramic Coatings on Building facades: A Case Study in Rio de Janeiro, Brazil

Ceramic coating has been widely applied in facade projects as an element that adds value to buildings since it has a wide range of colors, textures, and options available. However, over time, ceramic facades begin to show damage and deterioration. Among the pathological manifestations that affect ceramic coatings, efflorescence, cracking, and loss of adhesion between the tiles and the substrate are considered the main ones, with the latter being the most serious due to the risk of accidents if any piece becomes detached. The globally used test for diagnosing this anomaly is the tensile bond strength test, but this method has limitations for widespread use. Alternatively, there are simpler methods that do not require specific equipment, such as visual inspection and percussion testing. Therefore, this study aims to compare these testing methods to evaluate the feasibility of using simpler and cost-effective methods for diagnosing bond loss in facade coatings. For this purpose, a comparison between the results of percussion testing and tensile bond strength testing was conducted on the facades of a building in Rio de Janeiro, Brazil. The results presented that percussion testing was able to accurately estimate areas with insufficient bond strength as determined by the bond strength test. Additionally, weakened areas were observed on facades with greater exposure to winds and a stronger influence of darker tile colors, which correlated with a higher frequency of anomalies.