Concrete is a very strong building material and it is used quite extensively both in residential and commercial construction. On its own, however, it does not look very attractive considering its dull gray color. Coating it with paint, however, can easily make it quite appealing.
Painting concrete involves several steps to assure that the paint will not prematurely peel off. These begin with degreasing and cleaning the surface for painting. Chemical degreasers with varying strengths are available in the market. Unless the concrete floor is heavily soiled and stained with oil, a general purpose degreaser usually suffices.
If the concrete is new, be sure it fully cured before painting it. Typically, it takes 28 days for new concrete to cure. Check, too, for moisture. If there are traces of it in the concrete, find out where it is coming from and take steps to prevent it from getting into the concrete.
Smooth and hard concrete is generally not a good substrate for paint. To make it more suitable for painting, it must first be roughened to a texture similar to that of medium sandpaper. This is accomplished with the application of an acid etcher. When this is done, thoroughly wash away the acid with water until no residue is left. If needed, mix household ammonia with the water to neutralize the acid.
Epoxy paint is the best coating that can be given to exterior concrete surfaces, including floors. This is because of their durability, excellent bonding strength, and low porosity. It is thus recommended that you use epoxy paint for your exterior concrete floors. You can, of course, also use acrylic paints that allow the concrete to breathe. Alkyd paints, on the other hand, are not generally recommended because of their tendency to trap moisture within the concrete.
After acid etching and cleaning, you are ready to apply the bonding primer. This guarantees that the paint will adhere securely to the painted concrete surface. Just be sure that your primer and paint are compatible with each other. Wait for the primer to dry for at least a day before applying the paint.
To make the painted concrete surface less slippery, you can add silica sand or other commercial additive to the paint to roughen the surface only enough to turn it into a non-skid floor.
You can use one or two coatings of the paint, depending on how much foot traffic you expect, but be sure to allow the first coat to dry for at least half a day before applying the next. After you have applied your last coat, wait for a week before opening up the painted area.