Masonry Magazine June 1968 Page. 23
NCMA TEK 10
National Concrete Masonry Association, 1968
An Information series from National Concrete Masonry Association
Decorative Waterproofing of Concrete Masonry Walls
JUNE, 1968
4
Concrete Units
General
In masonry walls, waterproofing is the process of controlling moisture where flow is caused by hydrostatic head. The term is also used to signify dampproofing, when the passage of moisture is not caused by hydrostatic pressure. For walls which require waterproofing, a variety of protective coatings is available in many compositions and colors. When properly applied to concrete masonry walls, these coatings not only serve to seal the surface against moisture but also provide an attractive, decorative finish.
The probability of rain penetrating an exposed vertical masonry wall to the extent of causing dampness on the interior is dependent upon the location of objects such as overhangs which tend to shield the wall and weather conditions prevailing in the geographical location of the building. Similarly, variations in wet and dry subsoil conditions affect masonry walls below grade. As a result, not all concrete masonry walls require waterproofing.
Types of Coatings
Many products have been marketed for use as waterproof coatings on masonry with varying degrees of success. Manufacturers are continually experimenting with new materials and chemicals in attempting to improve protective coatings. The basic constituents and pertinent characteristics of the types of waterproof coatings currently available for use are discussed here.
Fill Coats
Fill coats, also called fillers or primer-sealers, are used to fill the voids in porous concrete masonry and smooth out surface irregularities on open or coarse textured masonry before the application of finish coats. Fill coats contain regular portland cement as a binder and some form of finely graded silicious sand filler. Acrylic latex or polyvinyl acetate latex is