Sprinkle a few drops of water on your floor to determine whether a sealant has been applied to it. The water will soak quickly into the concrete if the floor isn't sealed. If the floor is sealed, water will bead up, and you won't be able to stain it. You may be able to find chemicals to remove sealant at your home-improvement center.
- Sweep and vacuum the floor thoroughly, then wash it with a strong degreaser. Rinse the floor, and allow the concrete to dry.
- Use an etching cleaner to clean the entire floor. It will remove stubborn dirt and open the pores of the concrete so the stain can penetrate. Mix one quart of solution with three quarts of water. Then dampen the concrete with water, and begin spreading the etching solution. Pour the solution in a 10' by 10' area (Image 1), and work it into the concrete with a stiff-bristle brush (Image 2). Keep the floor wet while you clean the concrete, and be careful not to over-clean any areas. If you do, the stain could soak into the concrete unevenly. Wear eye protection as well as clothing that will protect your skin from the harsh etching solution.
- Rinse the floor thoroughly with water, and allow the concrete to dry for 24 hours.
Mix one gallon of stain with one pint of water.
Apply the first coatw of stain to the concrete floor.
Use a paintbrush to stain the floor near corners (Image 1), then roll paint onto the floor with a short-napped roller (Image 2). Work in 3' sections, and be careful not to paint yourself into a corner. Allow the first coat to dry for 2 hours, then apply a second coat of undiluted stain.
Make sure no one walks on the floor for at least 24 hours, and avoid parking on the floor for three days.