Water Repellency Tests for Concrete Masonry Units

Evaluating the water repellent characteristics of concrete masonry units is important to ensure that the proper level of protection is provided from the weather in certain applications. NCMA TEK Note 19-7 provides specification information on the required performance of water repellent CMU, and several industry-developed tests methods are referenced. These three tests methods are:

Test Method CMU-WR1 contains standard tests methods for water stream and water droplet tests of concrete masonry units. The purpose of these tests is to visually assess the water absorbency characteristics of the exposed surfaces of a hollow or solid concrete masonry unit when subjected to either a dynamically or statically applied source of water. This test is intended to be quick field check on repellency, and if questionable results are obtained additional laboratory testing is required.

Test Method CMU-WR2 contains the spray bar test method for concrete masonry units. The purpose of this test is to visually assess the migration of water through the exposed surfaces of a hollow or solid concrete masonry unit when multiple streams of water are applied to its outer face for an extended period of time. This test is intended to be performed in a testing laboratory.

Test Method CMU-WR3 contains the test method for assessing water uptake potential of concrete masonry units. The purpose of this test is to evaluate the resistance of a concrete masonry unit to vertical moisture migration due to capillary action, a migration often referred to as wicking or water uptake. This test is intended to be performed in a testing laboratory.