Choosing the right size pressure washer to clean your house depends on the type of materials you’ll be cleaning and the extent of the job. If you’re trying to clean exterior vinyl siding, decks, and patios, the best pressure washer should be between 2000 and 3000 psi. For stucco, aluminum, or soft wood, choose a pressure washer with a lower psi (1200 to 1800 psi) to avoid damage.