The washing of concrete surfaces is normally done with high pressure, using pressure washers along with special driveway cleaning devices. Also some bleach may be used. Our patio cleaning services will remove all mold, mildew, etc. Concrete will look great when washed, there is usually a noticeable difference once cleaned. Some concrete (especially new construction) may have stains which may not be removed, usually red in color. Some staining may be removed using acid.
Concrete (especially garage floors) may be acid etched to remove sealants, and various staining, especially if concrete is to be stained with a special concrete stain.