How to Clean Concrete Floors
A power washer is the easiest way to clean concrete outdoors. You should be able to blast away dirt, mildew and grime in an afternoon. Rent one and read the instructions on how to use the machine before you start the project. Spray the patio surface with a detergent and use a stiff brush to scrub it into the concrete. Never use a metal-bristle brush. Metallic fibers can get trapped in the porous surface of the concrete and rust. Put on safety goggles and gloves. Turn on the pressure washer. Move the wand from one side, using the same motion as you would if you were mopping a floor.