A method of cleaning a surface such as a driveway or a vertical wall which includes converting or retro-fitting a zero-turn radius (ZTR) or other type of mower to a cleaning apparatus. The conversion of the mower includes the steps of adding a water supply tank to the deck area of the mower and providing low pressure and high pressure flow lines. The low pressure flow lines are supplied via a low pressure pump. The high pressure flow lines are supplied by a separate high pressure pump unit. Plural solenoid valves are utilized in the method and system to control the flow of a cleaning solution for various method operations.