The average cost to professionally clean or pressure wash a deck is around $150, with prices typically ranging from $100 to $600. Several factors influence the final price, including the deck's size, material, condition, and how long it has been since its last cleaning. For a smaller deck of about 300 square feet, you might pay around $100. For a larger deck of 1,000 square feet or more, the cost could be closer to $300 to $400. Decks that are very dirty or haven't been cleaned in years may require more time and special detergents, which will increase the price. The deck's material also plays a role. Wood decks often cost more to clean because they require a gentle power washing technique to avoid damage. Composite decks are typically less expensive to clean, and cleaning a metal deck may cost around $100.

Many composite decking manufacturers, including the popular Trex brand, offer warranties that protect against warping under specific conditions. These warranties typically last between 20 and 50 years, but they usually exclude claims related to improper installation of the product. Some manufacturer warranties only cover decks built by certified professionals.

Building a deck without a permit could lead to fines for both the homeowner and the contractor. The exact penalties will depend on your state and municipal building laws. You might also be required to remove the deck and apply for a permit before you can build another. While it might be tempting to skip the permit to save a few bucks, it’ll cost you much more if you’re caught.

Pressure-treated decking may be worth it if you want a natural, insect- and rot-resistant decking material that will last for decades with proper maintenance. As such, it’s a much better option than untreated pine. Alternative wood decking materials like cedar and redwood tend to be less durable and more expensive. Some homeowners prefer composite decking, which is a low-maintenance alternative to wood but is also more costly.