Hardiplank, manufactured by James Hardie, is a siding made of cement and cellulose wood fibers that is designed for use on houses and small buildings. It serves to protect a structure from outdoor elements, such as rain, snow, dirt and dust. However, these elements can build up on the siding, leaving it looking dirty or, worse, causing mold and mildew to form. Clean the siding every six to 12 months to keep the exterior clean, new-looking and free of mold and mildew.
Spray down the Hardiplank siding with a hose.
Fill a cleaning bucket with liquid dish soap and warm water. Dip a large sponge or scrub brush into the soapy water.
Scrub away any spots, stains or dirt spots not removed with water.
Spray the siding down with the hose to remove soap residue.
Allow the siding to air-dry.