A pressure washer is a fantastic tool, but if used incorrectly can cause many problems. Tim Carter of AsktheBuilder.com demonstrates the basics about pressure washers and power washers so you get excellent results without hurting your property or yourself. Use pressure washers to clean driveways, decks, sidewalks, concrete or tile patios, or fences. It is not a good idea to use very high pressure to clean your home or roof. Use low power to clean the walls or roof.