The manufacturer of Hardie Board siding recommends that you avoid pressure washing your Hardieplank siding since the hard spray of water from the power washer can damage the surface of the siding. Instead, you should use a soft cloth and a soft bristle brush to clean your siding. It’s important to wear safety goggles and gloves, gather your equipment and start cleaning.

Cleaning your James Hardie siding once or twice per year using a soft brush, cloth, and a garden hose can restore its sparkle. Avoid using anything abrasive, as this can leave marks on the fiber cement siding. Start cleaning at the top of a small section, so you can clean anything that drips or streams down.

To clean, wet your cloth or brush using the garden hose. When using a brush, use it to brush any dust or dirt off the siding, then rinse the area with your hose. If using a soft cloth, dampen the cloth, then wipe a small area from one side to the other in the direction of the plank, shingle, or panel siding. Finally, rinse the area with your hose.