- 1). Scrub the concrete floor with a stiff-bristled brush. Brush vigorously to remove any loose particles.
- 2). Mix trisodium phosphate (TSP) and water according to the TSP directions. Mop the floors with the solution to remove grease and grime. Let the floors dry completely.
- 3). Dip a putty knife into the concrete patch compound. Fill any holes or cracks in the concrete with the compound. Smooth the top of the concrete and compound so there are no high spots on the floor. Allow the compound to cure based on the package directions.
- 4). Attach medium-grit sandpaper to an orbital sander. Sand the floors with the sander. Move the sander up and down and back and forth to give the floors a texture that will allow the primer to adhere to the floor.
- 5). Apply a thin, even coat of floor and deck primer to the concrete floors. Paint the corners and any areas that the roller can't reach with a trim brush. Follow with a ¼-inch nap roller to apply the primer to the rest of the floor. Add more primer coats as needed until you can no longer see the gray concrete through the primer.
- 6). Paint the floors using the same technique you used to apply the primer. Porch and floor paint will withstand heavy foot traffic better than paints intended for walls. Apply two to three thin coats of paint for a more durable finish.
Source...