The same applies to fences. Dirt, grime, mildew, and even cobwebs create a slick, uneven surface that repels paint. Picture cell phone professionals installing your new screen cover. Recall their tenacity at removing even the smallest speck of dust from your screen before placing the protector. All of this is done to avoid air bubbles and ensure proper adhesion. Pressure washing removes the contaminants that would cause adhesion issues when painting your fence. It also reveals the natural texture of the wood grain. This creates a perfect canvas for the paint to adhere to, ensuring a more even, professional-looking finish.