Cleaning siding with a pressure washer requires the correct method to fit the job.
Low-pressure washing is a common technique used to avoid damage to the surface, especially when painted. Professional pressure washing contractors have used high pressure equipment in the past, however, low-pressure, high volume pressure washing equipment using specific cleaning solutions have been introduced to achieve effective cleaning while lowering the possibility of property damage.
First, thoroughly wet all plants and the ground around the area to be cleaned to avoid killing plants, then apply the appropriate cleaner for the job and let it soak according to directions. Pressure clean the surface being sure not to get the tip too close to spray through gaps or damage paint, but close enough to do more than just rinse. When finished, be sure to thoroughly rinse the plants and grounds around the area to prevent damage.
To remove graffiti can be more difficult. Cleaning siding with a pressure washer using high-pressure water in combination with cleaners aids in the removal. A hot-water washer is sometimes helpful, especially for crayon. Sometimes a pressurized mixture of water and sand is used to blast off the surface of the vandalized area, but this can etch and damage the surface. Graffiti using paints that bond with the siding offer few options, and sometimes have to be painted over.
Precautions
Pressure Washers can damage surfaces. High pressure washers can bore-through wood and masonry and strip the paint off surfaces. Be especially careful while using high pressure to avoid damaging the surface or causing personal injury. Water can be forced deep into bare wood, under planking and through cracks in masonry leading to an extended drying period. Such surfaces can appear dry after a short period, but still contain significant amounts of moisture that can hinder painting or sealing efforts. Be sure to give ample drying time before applying finishes.