Expect to spend around $10,000 to $11,000 to replace a 20-by-20-foot deck. Using high-end materials like composite or exotic hardwoods can drive up the cost, as can custom features and design elements. You can also expect to pay more than average if your deck replacement requires a site evaluation or if you need the work done during the busy season.

Deck skirting shouldn’t touch the ground, especially if you have a wood deck, which is vulnerable to moisture. Ideally, you should leave at least 3/4 of an inch of space between the deck skirting and the ground for more ventilation. Pros also recommend that you incorporate about 1 square foot of space for ventilation for the underside of the deck to every 150 square feet of decking. Proper ventilation prevents mold growth and rot that can damage your deck.

The best base materials for a ground-level or floating deck are typically gravel and crushed stone (also known as landscaping rocks). These options are inexpensive, provide excellent drainage, prevent weeds, and help minimize moisture buildup, which reduces shifting and rotting. For added stability and to evenly distribute the weight, you can use concrete deck blocks or pavers. While more expensive, concrete blocks and pavers offer a sturdier base than gravel or crushed stone alone.

It is possible to pressure wash your deck, but it’s usually best to leave the work to a professional for two main reasons. First, power washers are expensive, and you can avoid high upfront costs by hiring a deck washing pro instead. Second, you must be careful to use the correct setting to avoid damaging your deck material. You can only clean soft woods like pine with a wide spray and a low pressure; otherwise, the water will leave unpleasant marks on your deck. Hard woods, composite material, and metal can stand up to increasingly higher water pressures.