Weather resistive barriers : new methodology for their evaluation

Effective weather resistive barriers (WRB) perform important functions in retarding waterentry into walls and in controlling water vapor movement as well as the amount of energyattributed to air leakage (Burnett, 2000; Weston et al 2001). Recognizing this, a public andprivate sector research consortium was established to develop reliable and precise methodsfor evaluating their performance.This paper, third in a series, provides an overview of the most significant results obtainedduring the consortium work. This research included development of two new test methods,namely the modified inverted cup (MIC) and liquid penetration resistance (LPR). Theacceptance criteria for these newly developed test methods are also postulated. This researchwork did not aim to evaluate the performance of the WRB products under various climaticconditions. However, development of this evaluation methodology could lead to generatinginformation on the basis of which such judgments might be made in the future. It is alsobelieved that the proposed test methodology will replace test methods currently used in codesand standards for evaluation of WRB products.