The prevention of rain penetration through external walls and joints by means of pressure equalization

Abstract

The mechanisms of rain penetration through walls and joints are described and a theory explaining the function of the pressure equalizing rain-screen wall is reviewed. The results of laboratory tests substantially confirming this theory are presented. The paper explains why some traditionally satisfactory forms of construction perform well, and suggests that the principles of pressure equalization should be applied when forms of wall construction and joints are developed and appraised. Through better understanding of these it should be possible to design and construct walls from which the problems of rain penetration is virtually eliminated.