Applying too much sealer to a deck might seem like extra protection, but it can cause more harm than good. Wood is a porous material with a limited capacity to absorb liquids. When you go overboard with sealer, the excess can't soak in and instead forms a film on the surface. This leftover layer is prone to peeling, cracking, and trapping moisture, ultimately defeating the purpose of sealing in the first place. 

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.

You can nail or screw composite decking, but 3-inch decking screws are the better fastener choice. Unlike nails, decking screws won’t back out of the composite material over time. There’s also little danger of splitting composite material when driving screws, so you don’t need to pre-drill holes unless otherwise recommended by your decking manufacturer.

Composite decking requires a solid foundation, substructure, or subframe to ensure stability. This base is typically composed of posts, beams, joists, and footings. The frame's joists can be built from various materials like composite, plastic, timber, or metal, as long as the base can support the deck's weight without shifting. A professional deck builder might recommend installing the frame on a solid concrete base for added durability. The final design and materials for the substructure will depend on your budget, the type of deck, and environmental conditions.