Yes, it is highly recommended to wash a house's exterior before painting to ensure the best results. Cleaning the surface removes dirt, dust, grime, mold, mildew, and old paint, which allows the new paint to adhere properly and results in a smoother, long-lasting finish. Failing to clean can lead to poor adhesion, peeling, and an uneven appearance. Pressure washing is an efficient method for this, but be cautious not to use excessive pressure that could damage siding or wood. For materials like vinyl or stucco, soft washing might be a better option. After washing, allow sufficient drying time, such as three to four days, before painting to prevent trapping moisture, which can cause blistering or peeling.

Even at the lowest setting, there’s always a risk that pressure washing might damage your shower or tub. Never use this technique if there’s pre-existing damage in your shower or tub, like peeling caulk, sealant, or cracked tiles. And skip this method entirely if there are any wood features present.

The average cost to pressure wash a house is around $310, with typical prices ranging from $200 to $420. However, the total cost can vary widely, from $200 to $750. Power washing, which uses heated water, may cost between $250 and $400 per project, with an average of $200 to $300 for a 2,000-square-foot home.

Key factors that influence the final price include:

• The size and height of the house (a multi-level home costs more than a single-story one).

• The complexity of the job and accessibility of certain areas.

• Geographic location.

• Equipment and hourly labor costs.

Hiring a professional is often recommended as they bring their own equipment and cleaning solutions. Experienced professionals know how to complete the job effectively without causing damage to your siding, gutters, or landscaping, which can be a risk with high-powered water jets.

Yes, it is important to wash your deck before painting to ensure the paint applies well and adheres properly. While you don't have to use a pressure washer, it is one of the most efficient cleaning methods. Pressure washing can quickly remove dirt, wood fibers, and flaked paint, getting deeper into the wood than manual scrubbing. You can also clean the deck with a stiff broom and a cleaning solution. Regardless of the method, a clean surface is essential for good paint adhesion. Make sure the deck is completely dry before applying any paint.