Volume 4, Issue 8 (September 2007)
Evaluation of the Effectiveness of Clear Water Repellent Coatings on Partially Grouted Single-Wythe Concrete Masonry Walls
The use of architectural concrete masonry to construct commercial and institutional buildings is common in the northwestern United States. By combining different block sizes, shapes, colors, and surface treatments, architects have designed many striking structures. This test program focused on the evaluation of clear water repellent coatings because they are an important component of a water resistant wall system. The number of repellents produced has grown and their chemical composition has changed during recent years. The test results will provide guidance in updating the industry recommendation used by design professionals and building owners. A total of 14 walls were constructed and tested in accordance with ASTM E 514, “Standard Test Method for Water Penetration and Leakage Through Masonry.” The walls were all constructed with materials shipped from northwest block producers and represent construction techniques used in the Pacific Northwest. Each wall was initially tested uncoated to establish a baseline performance. Afterwards, a clear water repellent was applied and each wall was retested. The walls were then tested a third time after aging outside for approximately one year. The test results will establish comparative behavior between wall assemblies.