Most performance standards for building envelope components, such as those for certified windows, have been developed for evaluating new products or for helping assure the quality of mass produced products. There are, however, few standard procedures for evaluating performance problems with installed wall systems. Many investigators have attempted to apply performance standards for new assemblies to problematic buildings; and this often leads to the wrong conclusion regarding the cause of building leakage.

This research explores the appropriate use of water test procedures for field investigation of leakage through building walls. We explore both the type of testing and appropriate criteria for judging the contribution to leakage from various components of the exterior envelope. We also discuss a methodology for developing test parameters based on actual weather records and surrounding topography. These exposure conditions can be used to formulate test pressures that can be applied to elements of the building envelope during water testing to more closely simulate the past exposure conditions that these wall components experienced during leakage events.