Performance evaluation of water repellents for above grade masonry

Abstract

Water penetration across brick masonry exterior walls is a problem that building owners and construction professionals must deal with frequently. Water repellents are often used in an attempt to resolve water penetration problems in certain remedial applications. Unfortunately, the information available to building owners and construction professionals regarding the use and evaluation of water repellents is limited. Little practical information exists to assist in the selection of such products and in the evaluation of their performance and durability. As part of a CMHC research project, Patenaude-Chiovitti Inc. carried out an evaluation of such products, exposing problems of performance evaluation of water repellents for above grade masonry. Six series of tests were conducted using a modified ASTM E-514 procedure and water uptake tube methods to evaluate the performance of five commercially available masonry water repellents. The results of the study have indicated substantial improvements in the resistance to water penetration upon application of these products to clay brick wall assemblies. The data accumulated during this study may have also revealed a trend indicating an increase in the rate of water penetration from the time of product application (i.e., reduced repellency), necessitating product reapplication after a given time interval. Readers are cautioned in the interpretation of the test data without additional information pertaining to the vapour diffusion characteristics of the applied products and durability concerns.