Before applying a protective coating or other floor covering to a concrete slab, ensure that the moisture content in the concrete has decreased to an acceptable level - typically ≤75 % relative humidity (RH), 3 lbs/1000 sq. ft./24 hours MVER or ≤5 % moisture content (MC).

If this is not the case, moisture can accumulate under the coating or floor covering and lead to discolouration, peeling, buckling, blistering, adhesive failure and/or mould growth. There are various methods for measuring concrete moisture. The two most common methods are non-destructive electronic impedance meters (ASTM F2659) or in-situ relative humidity probes (ASTM F2170).

Properly testing the moisture content in the concrete prior to installing a flooring system is a necessary part of quality control and assurance to reduce the likelihood of flooring system failure.