Impact of Environmental Exposure on the Service Life of Facade Claddings-A Statistical Analysis

Facade claddings, as the outer protection layer of the building's envelope, are directly exposed to environmental degradation agents. The facades' orientation and their distance from the sea, among other location and protection-related factors, influence their vulnerability to climate loads, in particular wind and air humidity. These loads, as well as exposure to air pollution, affect the degradation process of claddings and the durability of facades. Therefore, studying the impact of the environmental exposure conditions on the service life of different external claddings provides useful information on their performance over time, which can support (i) decision-makers in the selection of the best facade cladding solutions and (ii) further research on the impact of climate change on building components. This study covers six types of cladding: rendered facades (R), natural stone cladding (NSC), ceramic tiling system (CTS), painted surfaces (PS), external thermal insulation composite systems (ETICS), and architectural concrete facades (ACF). Three hundred facades located in Portugal are analysed according to three main groups of variables, which characterize (i) the facades, (ii) their degradation condition, and (iii) the environmental deterioration loads and context. The statistical analysis results reveal that the environmental variables affect the cladding degradation process. South-oriented facades present lower degradation conditions than facades facing north. The distance from the sea and high exposure to pollutants add to the degradation conditions, reducing the expected service life of facades. The results reveal that claddings can be organized according to two main groups: the most durable (CTS, NSC, and ACF) and the least durable (R, PS, and ETICS) systems. This study enables a comprehensive analysis of the data, useful to draw conclusions about the influence of environmental exposure conditions on the degradation and service life of facade claddings.