There are two main field testing methods used for water repellency of concrete masonry units (CMUs), for quality assurance before being placed in a wall: droplet and RILEM tube testing. Completed assemblies can also be tested with RILEM tubes or other standard water spray tests such as ASTM E514, Standard Test Method for Water Penetration and Leakage Through Masonry.
A single-wythe concrete masonry wall may be a cost-effective structural element, but it can present challenges for waterproofing. The National Concrete Masonry Association (NCMA) recommends redundancy to keep concrete masonry walls dry through techniques at the surface of the wall, within the wall, and through adequate drainage systems. Unfortunately, many concrete masonry wall designs rely solely on admixtures in the concrete masonry units (CMUs) and mortar and surface-applied water repellents. However, low absorption values do not guarantee water penetration resistance; this disconnect in the industry is a leading reason for leakage in single-wythe concrete masonry walls.
“A building is only as strong as its foundation,” is a common idiom uttered across the construction industry. Time can be spent applying this to anything, in the metaphorical sense, but in the construction business it can be taken literally. The foundation is literally the building block on which the rest of a building will rely for long-term function and performance.