For contractors who place concrete floors that require coverings, the results of moisture-vapor emission tests can mean the difference between a project that remains on schedule and one that falls weeks behind. Consider the following scenario. A floor-covering manufacturer recommends a moisture-vapor emission rate no higher than 3 pounds/1,000 square feet/24 hours to guarantee proper performance of the floor-covering adhesive. But 3 months after the contractor places the floor, testing of the slab concrete in accordance with ASTM F 1869 yields a 3.5-pound moisture-vapor reading. The building owner now must delay occupancy until the floor reaches the required emission rate and the flooring can be installed.
In situations such as this, the first question contractors are likely to ask is: "How reliable is the test result?" To answer that question, the authors conducted 232 laboratory and 144 field tests in accordance with ASTM F 1869.