What They Can and Can't Do
Pressure washers are great for removing deep-seated dirt, grease, peeling paint and even graffiti from concrete, asphalt, siding, decks, lawn furniture, garbage cans, boats and trailers, and outdoor power equipment. Electric models can remove light stains and dirt from concrete but may not have enough oomph for the heavy stains.
With accessories, you can turn your gas-powered pressure washer into a wet sandblaster or use it to power a water broom or a mechanical sweeper. Add a telescoping extension wand and gutter cleaner (such as the General Pump Giraffe) and you can clean your second-story siding and gutters without climbing a ladder.
But pressure washers are also very good at destroying items around your home. The high pressure can break windows, gouge wood siding and decking, and force water behind siding and flashing, causing extensive damage. They work great for blasting mud off your car or truck but leave a fine film of dirt behind. A regular garden hose and wash mitt actually work better for normal car washing.