Functional and Physical Service Life of Natural Stone Claddings

Abstract

During their lifecycle, a building and its components should fulfill a set of performance requirements. However, in reality, from the moment in which a building is placed in use, its deterioration process begins. Buildings and especially their facades, more exposed to the external environmental agents, suffer throughout their service life several types of depreciation, becoming obsolete, economically destitute, or physically deteriorated, leading to the end of their service life. This paper intends to establish a correlation between functional criteria (FBSL) and physical degradation (Sw) in the definition of service-life prediction models. In this study, these models are applied to 203 natural stone claddings (directly adhered to the substrate), located in the Lisbon area, Portugal. The functionality and degradation condition of the facades analyzed are evaluated through visual inspections. Vulnerability and risks (intrinsic and extrinsic variables) are considered in the evaluation of both methods, as the factors that affect the physical and functional service life of buildings. These models are implemented based on a survey of expert opinion. This study allows establishment of a hierarchical scale concerning the priority of intervention in the stone claddings, based on physical and functional criteria. This information is extremely important in the implementation of maintenance programs in large building stocks.