There are two sources of moisture that influence the level within a concrete substrate. Free-water that is not consumed in the process of cement hydration and remains as nonchemically bound water in the concrete. Time and suitable drying conditions are required to reduce the amount of free-water in a concrete slab to a level acceptable for a flooring installation.
The second major source of moisture in a slab-on-ground is that which originates below the slab. When an effective vapor barrier/retarder material has not been properly installed directly beneath the concrete, moisture vapour from below the slab will migrate upward to, and into the concrete which will cause blistering and bond failure if not treated before installing the new epoxy floor.
Floorcrete uses different methods of testing to measure the moisture vapour transmission rate and the moisture content. There are at least five systems to mitigate a high moisture or pH condition.
Combination of Systems
How to know what system to use depends on the condition of the floor, amount of moisture, what epoxy system is being applied, and budget.