Quantifying Wind-driven Rain Intrusion – A Comparative Study on The Water Management Features of Different Types of Rear-Ventilated Facade Systems

Abstract

The adequate protection against meteorological conditions of rear-ventilated façades rests on the optimization of the construction design for the joints, cavity depths and wall interfaces. In the late 1990s and early 2000s several authors analysed the water management characteristics of open joints in rainscreen systems, although only few of them attempted to quantify infiltration rates into the air cavity. However, none of these studies provided reliable quantitative data on wind-driven rain intrusion to the water resistive barrier of rear-ventilated façades. The provision of this data will give the means of determining the moisture load to which the façade is to be subjected during a rain event and for which the façade must be able to manage. Consequently, the aim of his paper is to compare quantitatively the water management characteristics of different types of rear-ventilated façade systems by adopting a holistic approach to this kind of enclosure system. In order to conduct this study, three façade systems have been selected based on the type of fixing method and the design of the vertical and horizontal joints. Afterwards, the full-scale mock-ups have been built and tested in controlled laboratory conditions. During these tests, the amount of water infiltrating into the air cavity and the amount of water reaching the water resistive barrier have been measured. Finally, a comparison between the results obtained for every mock-up has been made.