For floors that have been previously coated, not all of the existing floor coating needs to be removed prior to repainting a floor. However, all previous coating that does remain must be tightly adhered. The applicator of the coating is responsible for determining whether the floor will hold a coating or not.

For new concrete floors, old uncoated floors or the complete removal of existing coatings, proper surface preparation is your most important process. There are several steps in the process.

You must degrease and clean the floor. We recommend Great Lakes Laboratories' Extra Muscle Degreaser-Cleaner.

New concrete must be tested for curing compounds that are frequently applied to new concrete and can interfere with coating adhesion.

You must test for moisture in the concrete. If moisture is present, the floor should not be coated until the source of the moisture is determined and eliminated.

The final step before actually preparing the floor is to determine if the concrete surface has adequate profile. A hard slick surface can cause poor coating adhesion.

After thoroughly removing all traces of grease, oil, and sources of moisture, you are ready to complete the floor preparation process. All contaminants must be chemically removed by acid etching or mechanically removed by abrasive blast.

To create adequate surface profile (like the feel of medium sand paper), Muratic Acid or Great Lakes' Clean 'n Etch can be used to acid etch concrete floors for new coatings. After etching, thoroughly rinse with clean water to remove all residue. Household ammonia may be added to the water to help neutralize the acid.

Abrasive blast cleaning may be necessary to completely remove all existing coatings or curing compounds, in order to provide an adequate surface for painting. Be sure to clean the floor prior to abrasive blasting.

NOTE: Some floors may contain contaminants or moisture to such a degree that coating adhesion will be impossible even with abrasive blasting. If the floor has been heavily soiled with oil or contaminants, it is recommended that a core sample of the concrete be taken to determine the level of contamination. If the core sample indicates contamination into the concrete that can't be removed by abrasive blasting, the floor may never allow a coating to adhere.

Coating Application

The floor coating system you choose depends on what it's going to be used for. Epoxy coatings are a good choice for general maintenance on dry or wet floors. If a non-skid floor is needed, silica sand can be added to the epoxy, however, this makes the surface hard to clean. If the intended use requires a higher gloss finish with added chemical and abrasion resistance, a two component urethane topcoat is recommended. Caution: The floor will become slippery when wet.

Our recommended system for coating concrete floors is two (2) coats of Mult-E-Poxy 180 when topcoated with Pinnacle 330HS Polyurethane, to give the floor a hard, shiny finish and the maximum protection against abrasion and chemicals.

All products referenced in this article can be purchased from your local Diamond Vogel Paint Center. For more detailed information on coating concrete floors or for actual hands-on assistance, contact your Diamond Vogel representative or call 1-800-387-8426.

For more information on surface preparartion for concrete floors see the Concrete Preparation Techniques Bulletin.