Radon fundamentals and the effectiveness of coatings in reducing soil gas flow through block basement walls. Report for May 1988-March 1989

This paper gives results of an evaluation of six different coatings in specially designed chambers built around 1.5 sq m concrete-block-wall sections. Data were collected over a pressure range of 1-12 Pa with flows from < 0.01 to 50 standard liters/minute (SLPM). The six coatings were a water-based catalyzed epoxy paint, an elastomeric paint, a cementaceous block filler, a surface bonding cement, a polysulfide vinyl acrylic paint, and a latex paint. A major preliminary finding is that all six coatings proved to be highly effective (98-plus %) when enough material is carefully applied. This large variation in a small sampling of blocks is significant not only in the potential impact on coating performance but also, more significantly, that specification of blocks with low air permeability for new construction substructures could greatly reduce soil gas entry, even if left uncoated