Volume 3, Issue 9 (October 2006)
Evaluating Methods for Water Vapor Transmission of Moisture Vapor Suppression Coatings on Concrete
Moisture vapor suppression coatings are used on millions of square feet of concrete floor slabs to remediate distress of moisture-sensitive floor coverings. We evaluated the suitability of ASTM E 96 and ASTM D 1653 for assessing performance of these coatings. ASTM E 96 can take several months, whereas free films can be evaluated using D 1653 in one to two weeks. Both methods were in close agreement for 100 % solids epoxy coatings but differ considerably for water-based coatings. Several types of coatings became severely distorted during D 1653 testing and could not provide useful results, including cementitious and polymer latexes and urethanes. Repeatability for coated and uncoated concrete specimens using ASTM E 96 was comparable to published precision data for other materials. The authors recommend that water vapor transmission testing of concrete and coated concrete specimens be included in the scope of ASTM E 96.