Rain Control and Design Strategies

Abstract

Controlling rain penetration is one of the most important func tions of the building enclosure. Despite its importance, the design for rain penetra tion is typically based on experience and rules of thumb that make use of tradi tional details. Designers and analysts have no theory to guide them. This paper develops a rational means of describing, understanding, and classifying rain control for the above-grade enclosure. The manner in which walls and roofs actually control rain in service is then discussed. The rain control classification developed is a rigorous and practical means of un derstandmg the function of each layer and material in an assembly This approach will aid the development of realistic test methods and provide the means for a more accurate assessment of the reasons for enclosure failures and therefore the proper repair and retrofit strategies.