If your garage floor is stained with oil, grease, and rust, you can easily give it new life with a coat of concrete floor paint. Concrete floor paints are available in both oil (alkyd)-based and water-based (latex) forms, both formulated to resist stains and dry to a satin, non-slip finish. Latex concrete floor pains are relatively inexpensive and easy to apply, and are the most common choice for most people. Though garage floor paint is available in a variety of colors, you might want to choose a light color if you use the garage as a workshop. A light gray, for example, will reflect more light than a darker color.
As with indoor latex paints, concrete floor paint is applied with ordinary paintbrushes and rollers; products sold as one-part epoxy require the same treatment. Two-part epoxy coatings require more extensive applications, however. Paints that are made specifically for use on concrete floors should provide adequate slip resistance without additional additives. One reason latex paints are so popular is that they clean up with soap and water; oil-based paints and two-part epoxies require solvents for cleanup.
Painting a concrete garage floor may, however, require more detailed preparation than most indoor painting, since it is very important to clean the concrete thoroughly and repair any damage before you paint. OIl and grease stains will interfere with the paint's ability to bond with the concrete, and will also bleed through the finish.
Whatever type of paint you choose, read the instructions carefully. Pay particular attention to surface preparation and temperature suggestions. Most garage floor paint jobs that fail do so because the surface was incorrectly prepared or the surface temperature was too low to allow for a good bond. High humidity can also negatively affect the durability of the paint job.
Tools and Supplies You Will Need
- Concrete patching compound (if needed)
- Trowel (if needed)
- Wet-dry vacuum
- Stiff brush
- Concrete waterproofer (if needed)
- Etching solution or muriatic acid (if required)
- Pressure-washer (if required)
- Latex concrete floor paint
- Paint roller
Inspect the Garage Floor
Garage floor paint is best applied to concrete that is clean, dry, and free of serious cracks or damage. Cracks and small holes can be patched with a concrete patch product before painting. Use a trowel to force the patching material into cracks and holes. Concrete that is frequently wet should be treated with a concrete waterproofer before painting.
Clean the Garage Floor
Use a broom and wet-dry vacuum to thoroughly clean debris from the floor. Remove grease with a degreaser and stiff brush. Rinse the degreaser and allow the floor to dry. Heavy stains may require a pressure washer.
Etch or Acid Wash the Garage Floor
Garage floor paint adheres best if the surface of the concrete has a slightly roughened texture—like that of fine sandpaper. Garage floors that have been troweled to a smooth surface will need to be roughened to create a suitable texture for painting. This can be done with an etching product or muriatic acid—follow the manufacturer’s instructions carefully. You may need to etch or wash the surface twice to achieve the proper texture. Rinse the concrete thoroughly to remove any traces of chemicals, and allow it to dry completely before moving on to painting.
It is also possible to etch a smooth concrete surface by using a power grinder or sander rather than using chemicals. This is also a necessary step if you are painting over old paint. Make sure to vacuum and damp-mop the sanded surface thoroughly to remove dust before painting it.
Apply the First Coat of Concrete Floor Paint
Manufacturers of concrete floor paint often suggest thinning the first coat with a little water before application. This will improve the absorption of the paint into the concrete. It is also best to use a paintbrush for the first coat, as brushing works better than a roller for working the paint into the surface. Thoroughly brush on a complete but thin coat of paint, then allow it to dry thoroughly.
Apply the Second Coat of Paint
The second coat of paint can be applied full strength and in a thicker coat, using either a brush or a roller. In some instances, a third coat might be necessary, especially if the concrete is heavily textured. Clean up tools with soap and water.
Latex garage floor paint dries to the touch in a matter of hours, but it is best to let it dry at least a full day before walking on it and a full week before driving your car on it.