Pressure washing is the 1st and best method to insure that the existing coating of paint will last longer. It is also the best way to prepare for refinishing or painting.
If you pressure wash annually, you will extend the life of your paint by at least 3 years, and often a paint job can last 10 years. It is much less expensive to pressure wash than to paint.
Dirt, grime, mold and mildew can severely damage your buildings exterior and cause wood rot and premature fading. Regular pressure washing is the remedy.