Moisture Meter Test:Electrical impedance meters are one way to measure moisture and quickly survey the condition of a concrete slab. They’re also useful in searching for moisture problems that may occur at the perimeter of the room or around pipes that may be leaking below ground. Simply place the meter flat on the concrete and read the display. Measurements outside the specified range will require further testing (see Photo 2).
Calcium Chloride Test:Calcium chloride test ASTM F1869-09 produces quantified results of the amount of moisture vapor emitted from a 1,000-square-foot area (measured in pounds) over a 24-hour period. To be effective, the test site should be at the temperature and humidity levels experienced during normal use.
First, expose an area approximately 20” x 20” and remove all residual adhesives, curing compounds, sealers, paints and floor coverings. The best way to do this is with a grinder covered with a dust shroud attached to a vacuum (see Photo 3).
Relative Humidity Test:Test ASTM 2160 quantitatively determines the percent of relative humidity within a concrete slab for field or laboratory testing.
First, use a rotary hammer drill with a carbide-tipped drill bit to drill holes to the required depth (see Photo 6). For concrete drying from one side, drill the hole to a depth of 40% of the thickness of the slab.
Second, remove the dust from the hole using a vacuum cleaner (see Photo 7).