Yes. Have you ever put a piece of tape on something that was dirty or dusty? Applying paint on a chalky or dirty wall is the same principle – it won’t stick. How can you tell if this is a problem you have on your home? On the side of your home that has the most sun exposure, run your hand down the wall. The chalk will be on your fingers if it’s there. Every inch of chalky paint around the home will have to be removed before paint can be applied. I’m not talking about a rinse. I’m talking about keeping the pressure-washer tip about 3” away from the wall and go from the top of the wall down. When you see milky colored water, it’s being done right. This is what we do everyday on every house as standard preparation.
Call me for a no-cost estimate at (520) 668-8988.