What is pressure washing (power washing)?

Pressure washing (or power washing) is a cleaning method that directs water at high force through a narrow nozzle to strip away dirt, algae, mold, rust, and other stubborn buildup from exterior surfaces. The equipment combines a motorized pump that pressurizes water, a storage tank or direct connection to a water line, a hose, and a nozzle that concentrates the spray force onto a target surface.

Two key measurements define pressure washing performance. PSI (pounds per square inch) indicates water pressure, typically ranging from 1500 to 4000 PSI depending on the job and equipment. GPM (gallons per minute) measures water volume flow, affecting cleaning speed and coverage. A combination of both determines cleaning power.

Pressure washing handles heavy-duty jobs: removing years of buildup from concrete driveways and sidewalks, stripping paint or coatings from wood and metal, cleaning brick and stucco exterior walls, clearing mold and mildew from roof surfaces, and degreasing equipment. The force of the water does the work, requiring less or no chemical treatment on many tasks.

Unlike soft washing, which uses low pressure (under 500 PSI) and relies on chemical treatment for gentle cleaning on delicate surfaces, pressure washing applies mechanical force. This makes it effective on hardy materials but unsuitable for wood siding, vinyl, asphalt shingles, or painted surfaces that can sustain damage from high-pressure jets.