Pressure washers – particularly those powered by gasoline engines - offer unsurpassed cleaning power on many outdoor surfaces, including concrete, brick, siding, and asphalt. Unfortunately, the cleaning power of pressure washers can also cause injury and damage surfaces quickly.
A solid stream from a pressure washer nozzle presents the greatest potential for causing injuries and damage. These sprays are capable of stripping paint from concrete patios and driveways, pitting and etching plastic lawn furniture, and peeling away paint as well as wood from siding materials. Use the widest spray angle possible to dislodge soils from the surface you’re cleaning. It’s also best to spray the surface at an angle to reduce the potential for injury to yourself or bystanders from splash back.
Always wear eye protection and shoes when using any pressure washer. Ear protection is also a must when using a gasoline-powered model. Electric washers are quieter, but be sure to plug the machine into an outlet protected by a ground-fault circuit interrupter, or GFCI. (Most homes built since the early 1980s have GFCI-protected outlets in outdoor locations such as garages and patios.)
Never point the nozzle toward or even close to people or pets, even with the spray turned off.
Begin cleaning at a distance of about 2 feet (61 cm) from the soiled surface, and then work more closely if necessary. Don’t get the nozzle any closer than 6 inches (15 cm) away from the surface.
For more information, please read the HousekeepingChannel.com article, “Pressure Washers: Quick Cleaning for Less”
Reference:
Consumer Reports