PWNA Power washing Standards
Standard; Applies to the pressurized washing of exterior surfaces for maintenance and cleaning. Ensure all wash procedures comply with all national, state, and local laws regarding wash water reclamation.
Wood or composite maintenance Wash (pressurized cleaning of the wood or composite surface of a residential or commercial property)
Carefully remove any furniture or other items in the area to be cleaned to a safe location.
Pay special attention to any areas that may be affected by overspray on nearby vegetation and tie back any larger vegetation in the area.
Use only a biodegradable detergent. “Biodegradable” refers to detergent that is not harmful to humans, vegetation, or pets. “Detergent” refers to a water based solution that will kill mold and mildew as well as a good surfactant. (Surfactant: a compound that lowers the surface tension of a liquid).
Use the appropriate nozzle size with a spray angle no less than 25 degrees and a nozzle sized not to deliver greater than 600 psi
Apply detergent to the entire surface being washed by using a fan pattern soap nozzle.
Repeat soaping of area twice, with special attention to areas of mildew.
Switch to the rinse low tip and flush soap from the hose onto the desired area. When water is free of soap, rinse any surrounding areas that have been subjected to overspray.
Allow soap to dwell for ten (10) minutes without drying.
Wash the surface in a steady continuous motion with a fan pattern spray nozzle, not allowing the tip to get closer than 6” from the surface. Always wash with the direction of the grain or the direction of the board. Continue process until entire surface has been washed.
Thoroughly rinse all areas and any surrounding areas containing kick-ed up dirt or debris.