Concrete Coatings – Selection and Preparation Provide a Solid Foundation

By Cynthia Challener

The types of coatings available for concrete surfaces vary extensively, as do the applications of the concrete material itself. Despite its strength, con­crete must be protected, and coatings provide a first level of defense. In many cases, the decorative function of a coating is of equal or greater impor­tance than its protective ability. Choice of coating type is determined by desired performance characteristics and environmental conditions.

Regard­less of the ultimate purpose, proper preparation of the concrete surface must be completed prior to application of the coating in order to achieve opti­mum results.

Concrete is used in industrial, commercial, and residential settings, and in many cases is exposed to harsh environments. It is used as a flooring mate­rial, for walls, for secondary containment systems, and in tank structures, to name just a few applications. Although it is considered by most people to be a very strong building material, concrete is actually porous and weak and re­quires protection from deterioration and contamination.

Concrete does not flex, but tends to develop cracks that must be bridged with a flexible and elastic coating. Highly alkaline or acidic conditions can also damage con­crete. Protective coatings provide abrasion-, corrosion-, and chemical-resist­ance. They may also need to protect the concrete surface from blushing and exposure to ultraviolet light.

Additional functional properties can be imparted by concrete coatings. Safety properties, including skid and slip resistance, are often important in flooring applications. Water resistance, static control, reduced wear (dust control), and increased ease of maintenance are additional benefits of some coatings used on concrete surfaces. Coatings can also be used to mark aisle ways and hazard areas. Coatings applied for decorative purposes can im­prove the aesthetics of both horizontal and vertical concrete surfaces through the addition of color and texture.