Dimensioning metallic inserts of stone claddings: a case study

Abstract

This study proposes a methodology for dimensioning metallic inserts for the indirect fastening of granite claddings. The proposed methodology intends to solve an existing problem, observed in a case study analyzed in the city of Porto Alegre, Brazil. This case study is a residential building, which presents a severe detachment of the external granite cladding, generating serious materials’ damage in the building, also compromising the users’ safety. The pathology observed in this case study, evaluating the causes beyond the detachment of the granite cladding. The façades orientation and the exposure to prevailing winds could contribute to the claddings’ degradation condition. Nevertheless, the design and execution conditions seem to be the main cause of the existing condition of the case study under analysis. The evaluation of the case study reveals that the absence of an intermediate layer of metallic inserts in association of the presence of strong winds in the region, lead to an overload of the granite plates in their midline, causing the rupture of the elements, and, consequently, to the partial detachment of the stone plates. This study thus reviews the technical standards applicable at the construction stage, proposing the development of a method for dimensioning metallic inserts of granite plates in stone claddings, based on isostatic principles and in the flexural strength of stone plates.