Before you add a new layer of paint to the outside of your home, it's critical that you make sure that the outside is very clean: Painting over a layer of dust and grime is one of the easiest ways to ensure a coat of paint that does not last and has a lot of irregularities.
Scrubbing the house by hand is one option, but it's not the best idea and will take forever. Instead, most people end up using a pressure washer which scrubs away built up dirt using a powerful stream of compressed water. You can either borrow a pressure washer from a friend or rent one for a couple of days. It should only take a couple of hours to wash the outside of a normal house.
When washing, there are a few things you should be aware of. First, be sure to wear eye protection and also earplugs if your pressure washer is loud. It's important to keep moving when spraying water: if you spray water in one place for too long, the pressure washer may actually be powerful enough to remove the current layer of paint and potentially even damage the wood!
If you keep moving, you should remove most of the dirt without damaging the current paint or wood. Be sure that no one is nearby because the stream of water can be dangerous and the dirt flying off your house may get on their clothes or in their eyes! Of course, be sure that your house is dry before beginning to paint!
By:Jason Stevens