DO wear proper eye, face and hand protection when operating the equipment and power washing.
DO attach nozzles and/or accessories completely before starting the machine.
DO keep hands and feet clear of the cleaning nozzle at all times.
DO consider using a special cleaning agent if the surface shows heavy dirt and grime.
DO follow the equipment manufacturer's directions with respect to distance between the spray head and the surface -- typically 6" to 10" while power washing, although this varies with the PSI and spray width settings. (Moving too close may harm the surface; staying too far away may be ineffective.)