Exterior maintenance professionals suggest that homeowners should pressure clean their home's exterior before they paint any surface. But here's the key: the pressure-cleaned surfaces need at least three to five days of dry weather before painting begins.

The powerful stream of water emitted by these machines can damage paint. It can also nick or etch wood, he says, and even certain types of stone. What's more, these machines can be quite dangerous when handled improperly (see “Pressure Washer Safety,” below).

Both pressure washing and soft washing can be effectively used to prepare your surfaces for painting or staining depending the surface.

Power washing cleans the siding, wood, and other exterior surfaces so paint sticks to it better. This helps the paint look nicer and last longer, improving the curb appeal of your house.