Modified Inverted Cup Test Method for Evaluating Moisture Penetration through Construction Materials

Abstract This paper presents a state-of–the-art review of the modified inverted cup (MIC) test method. The inverted cup method was introduced into ASTM E96, “Standard Test Method for Water Vapor Transmission of Materials,” several decades ago. However, its capability in evaluating moisture response of building materials has not been fully realized. Recently, a consensus was reached to develop an independent MIC standard under the jurisdiction of the same ASTM committee. The MIC test method quantifies moisture transport in liquid and vapor phases together and has several advantages over its counterpart ASTM D779, “Standard Test Method for Water Resistance of Paper, Paperboard, and Other Sheet Materials by the Dry Indicator Method,” boat test method. The MIC test method can also be employed in evaluating effectiveness of surface treatments including hydrophobic sealers and coatings on material surfaces as well as water resistive barriers, water vapor retarders, and certain insulation products. This paper also discusses the differences between various moisture transport tests, including ASTM E96 water vapor transmission, D779 (boat test method), and ponding test to resolve confusion related to their use. The paper shows that the results of MIC tests are valuable in quantifying moisture response of different materials.