Homeowners with vinyl, metal, or composite siding should pressure wash their homes once a year. If you have wood siding, we recommend you pressure wash only when you have dirt or mildew buildup, unless you use very gentle pressure to wash away pollen or cobwebs on an annual basis.

The main difference is that power washing uses highly pressurized steam to do the cleaning while pressure washing just uses unheated tap water, without the help of a heating element.