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.

Yes, it is possible to add an under-deck drainage system to an existing deck by retrofitting it to the structure. This process may require some prep work. For example, many drainage systems are installed on top of the deck joists, which would require you to remove the decking boards and railings first. To avoid this, you could opt for a below-the-joist drainage system. For best results and to ensure proper installation, it is recommended to consult a professional. A pro can inspect your deck, make any necessary repairs, and then install the drainage system correctly.

In most cases, your deck will need some form of deck footing to hold it in place, preventing moisture from rotting your wood and decreasing your deck’s lifespan. Concrete deck blocks are the most common type of footing for floating decks. Some homeowners use ground-level deck footings. For added security, consider digging and laying your ground-level footings below ground.

For a 12x20-foot (240-square-foot) deck, you can expect to pay between $7,200 and $14,400. This cost is based on a general price of $30 to $60 per square foot. The final price will depend on factors such as the decking material, design complexity, deck type, location, and local labor costs. Keep in mind that add-ons will increase the total; for example, adding an under-deck drainage system to a deck of this size could cost an additional $7,700.