Pressure washers force a strong stream of water that's used to clean large surfaces. Some pressure washers generate a lot of force and should be used only by professionals. Others are designed for household use.

The trick to cleaning effectively with a pressure washer is determining the distance you should be from the surface to be cleaned. The closer you are, the more powerful the stream of water that hits the surface. If you get too close, the force of the water may damage the surface.

The most powerful pressure washers are run by a gasoline engine. These are good for big jobs such as cleaning the outside of a building or removing paint from concrete.

Electric power washers produce less pressure and are designed for smaller cleaning jobs such as washing cars and cleaning driveways. They're quieter and easier to use than gas-powered pressure washers.

Shoulder-carry power washers are used for medium-duty jobs such as washing windows or cleaning the dirt and rust from large power tools.