Garage Floor Moisture Testing Methods
Concrete moisture vapor emission is a natural occurrence of any concrete slab. Concrete is a porous substance that absorbs and wicks moisture from either above or below the slab. Most garage floors are poured with a vinyl vapor barrier underneath, however they can be damaged during pouring and tamping of the concrete, or even non-existent. If concentrated moisture is present it will create a hydraulic pressure under your top coating making it lift, bubble and peal.
Prior to coating a garage floor, it is highly recommended you test the garage floor for moisture before applying a top coat.
Freshly poured slabs have a high water content that must evaporate during the curing process. New concrete should be allowed a minimum 30-60 days to cure before a coating is applied. This pertains to all floors whether the slab is above or below grade. Besides the curing process of new concrete, long established floors can also wick moisture from sources below the slab, even when approved moisture barriers were installed. This moisture will naturally wick to the surface and can easily break the bond of floor coatings causing your garage floor coating system to fail.
Moisture Vapor Pressure
Humidity and temperature both have a direct effect on the pressure exerted on the concrete surface measured in “pounds per square inch”. Inside your garage the static vapor pressure is often one half the pressure seen inside or below the concrete garage floor slab. This indifference causes the moisture to literally be sucked upward, often trapped just beneath the floor coating materials. The hydraulic pressure exerted can easily lift epoxy and other floor coatings causing them to bubble and peel. It is crucial to use even the most basic testing methods to determine if your floor has an unacceptable moisture issue prior to coating. Read More →