Moisture Blocking Primers: Tips and Tricks by Jimmy McGhee

Moisture Blocking Primers

Epoxy floor coatings have become popular for many reasons including durability, abrasion resistance, and aesthetics.  However, an area of concern with some epoxy coatings is that they do not fare well with moisture vapor emissions from the concrete substrate. To combat against moisture vapor emissions, the epoxy flooring industry has developed primers that reduce the ability for moisture to pass through concrete slab.  Many people are not aware that they need a moisture blocking primer, and some people think that these types of primers are just and added cost that is not truly needed.

The first thing about using a moisture blocking primer is to know when it is needed.   Areas with a damp aroma or signs of efflorescence are clear indicators that there is a moisture problem.  An MVE (moisture vapor emissions) test kit can be used to determine the rate of moisture passing through the concrete during a time frame of 24 hours. If moisture vapor is overlooked, the consequences would include a coating that has excessive outgassing (formation of air bubbles, craters, and pin holes due to air rising form the concrete slab during an increase in substrate temperature), and blistering due to hydrostatic pressure.

Moisture blocking primers at Versatile Building Products come in clear and pigmented versions to fit your base-coat needs.  They wick deep into the concrete substrate to prevent any passage of moisture vapors.  Our moisture blocking primers also provide excellent adhesion for subsequent epoxy flooring applications.