The use of stamped concrete and concrete overlay was once limited in color. Now, that has all changed with new applications for color dyes and stains, appropriate for all stamped concrete designs. Residents no longer have to opt for stamped concrete and concrete overlay which remains a single, bland color, nor do they have to select a monochromatic exterior design. Topical film-building stains are like paint in that they are opaque in nature, making them perfect for a basic concrete overlay or stamped concrete. They reside upon the concrete surface but their bond can be enhanced if they penetrate the pore structure. Generally, the topical film-building pigmentation is made with mineral oxides because mineral oxides will not degrade when in ultraviolet light. The size of the pigment particles contained in the mineral oxides is the largest within the family of stains. However, those made with organic coloring agents have UV blockers contained therein which help to protect the color in a stamped concrete design or an exterior concrete overlay which is prone to severe weather changes and direct sunlight.
Stains which are film-based have bonding agents which aid the attachment to the concrete surface. Generally, acrylic polymers are used because of their positive bonding properties. The moisture vapor within the concrete can also pass through the acrylic polymers. Some companies use lithium silicate because of the good bond strength it contains. Lithium silicate reacts chemically to the calcium hydroxide within the concrete. This chemical reaction forms a surface which is abrasive-resistant and is not soluble in water after it has cured.