Water damage to masonry either directly or indirectly as a result of freeze-thaw action has long been a concern to the construction industry. Over the years, the industry has developed a number of tests to measure leakage in masonry walls. However, little attention has been given to the correlation between these tests and the factors that contribute to water penetration and leakage. The forces that compel liquid water from the outside of a masonry wall into the interior of the building are: capillary forces - the propensity for water to “wick” in porous materials or through hairline cracks kinetic forces - the kinetic energy of a wind-driven rain will force it into the depth of the wall pressure differential - net pressure differentials caused by ventilation and air conditioning systems may cause the water to pass through small defects in the wall gravity - under gravity water can drip in through imperfections in flashing and parapet walls surface tension - water will tend to follow an easily wet surface, even turning around corners and edges such as in soffits, shelf angles, and loose laid metal flashing.
This paper reviews the effectiveness of existing water penetration and leakage tests such as the ASTM E 514 Test Method for Water Permeance of Masonry, RILEM tube test, AAMA 501.2-83 and other similar tests in predicting the resistance of masonry walls to water penetration caused by one or more of these forces. The authors further suggest a simple test method to complement the existing ones. A theoretical treatment of these forces and their effects upon water penetration is discussed in a separate paper.