The importance of a pathology catalogue for diagnosis: the example of tile-coated façades

Abstract

Portugal has a long tradition of applying ceramic tile to façades with excellent results. However, recent years have seen a considerable increase in the pathologies related to wall and tiling materials characteristics, the type of adhesive and the application technologies. Many of the failures have been due to hygrothermal conditions to which the façades are exposed. In this paper we present a model to forecast the service life of adhesives for ceramic wall tiling, based on the results of an experimental study related to the influence of hygrothermal action on the adhesion failure of ceramic wall tiles. This study's main goals were to show the cementitious adhesives' performance varied during their service life, based on the analyses of accelerated aging testing results, and to explain some pathologies. Building physics is an important instrument for design, but the available knowledge is not always used to solve and prevent the development of a Building Pathology. In realtion to this the Building Pathology Study Group - PATORREB has been created. It is coordinated by the Faculdade de Engenharia da Universidade do Porto's Building Physics Laboratory (LFC, FEUP), and its principal objectives are to identify and disseminate the most frequent pathologies in Portuguese buildings. This Study Group created the Web site www.patorreb.com, where a Patholoy Catalogue, compiled by the various Portuguese universities has been posted. It is based on research and experimental studies of building pathology. The Catalogue consists of a set of Pathology Reports that contain a description of the problem, the diagnostics methods used, the definition of the main causes and possible solutions flor repair. KEYWORDS: Pathology, façades, ceramic tile coating, hygrothermal behaviour