1.1 This practice covers procedures for installing flexible, prefabricated sheet membranes in contact with earth or granular fill used as vapor retarders under concrete slabs. 1.2 Conditions subject to frost and either heave or hydrostatic pressure, or both, are beyond the scope of this practice. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropri