Tom Bosley -- who famously played Mr. Cunningham on  Happy Days  -- died this morning at a hospital in Rancho Mirage, CA ...
Average estimates: $250 to $420. Power washers can have pressures of 4,000 psi (pounds per square inch) to lesser pressures of maybe a few hundred and run by gas or electric. This means that professionals will probably use one with less pressure to clean a deck and maybe one with higher pressure to clean a patio.
1 Buying or renting a pressure washer to power-wash the deck in preparation can cost $40-$200 (but some experts advise using brushes and non-pressurized water because high-pressure water can damage decks).