This specification covers the properties and tests for bituminous membrane water vapor retarders used in contact with soil or granular fill under concrete slabs. Tests may be conducted on both new materials and materials that have been conditioned or exposed to simulate service conditions. The water vapor retarders shall consist of asphaltic materials reinforced with multiple plies of suitable fabric, and shall meet the following property requirements when tested: water vapor permeance; tensile strength; puncture resistance; and thickness. When specifically required by the buyer for use in special conditions, the retarders shall additionally adhere to properties such as resistance to plastic flow and elevated temperatures, effect of low temperature on bending, resistance to deterioration from petroleum vehicle for soil poisons, and resistance to deterioration from exposure to ultraviolet light.