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Abstract: Clay particles found in many building stones, when in contact with water, suffer aggregation–disaggregation and swelling–shrinking processes which can cause severe pathology. Whilst research has focused on historic buildings and masonry walls, studies regarding rainscreen walls are lacking. When using panels of reduced thickness fixed with punctual anchorage points, fissures or scaling phenomena can rapidly lead to rupture of panels, causing stability failure. This study aims to identify the causes of decay in a building with limestone rainscreen walls, in order to help to understand clay-related damage in this type of façade and its differences with regard to masonry walls. [Copyright &y& Elsevier]

Abstract: In current European construction, the building model of stone coverings detached from the building support is being increasingly used. These coverings remain joined to the rest of the façade only by certain anchorage points, leaving thus a cavity between the stone panels and the inner support. This is the model that best adapts to the actual concept of heterogeneous façade, with high performance qualities and predictable behaviour. Walls designed to achieve a high degree of air pressure equalization between the inner cavity and the exterior, obtaining considerable benefits, are known as Pressure Equalized Rainscreen (PER) walls. Existing design guidelines on these walls are mainly qualitative and referred to a theoretical continuous wall, with few references to real construction methods or discontinuities of the façade. Behaviour of PER walls, when built with stone panels of medium thickness (30–40mm) and open horizontal and vertical joints, is analysed in this study, based on the climate in the city of Valencia (Spain). Although panels of 12–20mm thickness are often used in many countries, the Spanish Technological Standards recommend using panels of at least 30–40mm in this type of façades, being thus this thickness the most common in Spain. The aim of the study is to understand rainscreen wall performance in this case, with regard to water coming into contact with the façade, and thus propose several design and construction recommendations to improve impermeability in crucial points of the façade. [ABSTRACT FROM AUTHOR]