Check the concrete for moisture

A DIY guide on How to apply an epoxy garage flooring

This post is a part of A DIY guide on How to apply an epoxy garage flooring

Conducting a moisture test is the next essential step. Look out for damp areas of concrete and any visible moisture or efflorescence.

When the moisture from underneath a concrete slab rises up and reacts with the salts and excess of lime in the concrete, a white powdery substance is formed. That powder is called efflorescence. It is the residue that is left behind after the moisture has evaporated.

Moisture in the concrete causes efflorescence.
Other contributing factors leading to efflorescence can be the collection of moisture at the surface of the concrete from condensation. This happens particularly in humid areas. Once the efflorescence from condensation is properly removed from the garage floor, it will not affect the epoxy coating.
It is advised to do a calcium chloride test if there are visible signs of moisture. This will determine if your garage floor qualifies for an epoxy coating. Commercial epoxy products can mostly withstand up to 4lbs of moisture flow per 1000ft² per 24 hours. If you have moisture issues, always consult the epoxy manufacturer regarding your calcium chloride test.

Sometimes the moisture on a surface is evaporating quicker than it is formed. This will make the garage floor look dry when it actually isn’t. If this is the case, do the plastic sheet test to be sure that there is no evaporating moisture anymore.


The next step, is properly cleaning the garage floor after confirming that it qualifies for epoxy coating .If the floor is free from any oil and grease or is brand new, then giving it a good sweep will suffice. You can proceed to the next step.
It is crucial to remove anything on the surface that may act as a sealer by repelling water e.g oil, grease stains, absorbed tire dressing, as well as old glue and mastics. These will not allow the epoxy to adhere properly.
You may want to protect your walls while cleaning. Taping up some cheap plastic drop cloth to the wall is a good idea.