The Functional Requirements for Water Resistive Barriers Exposed to Incidental Water Leakage, Part 2: Testing Materials

Abstract The first part of this paper presented classification of Water Resistive Barrier (WRB) products.4 The main purpose of the research reported in this part is not to determine how different WRB products perform under exposure in real assemblies but to evaluate the effectiveness of the existing test methods to characterize moisture performance of WRB products. An additional purpose is to assess what properties should be determined to enable characterization of WRB for use in computer models for heat, air, and moisture (HAM) transport. The investigation determined that the existing test methods do not provide adequate information. Therefore, new methods are proposed with a view to providing a better basis for evaluating WRB performance in wall assemblies.