Get matched with top deck cleaning pros in West Blocton, AL

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.

Before installing a deck, you must build a base for the deck to rest upon, often made of compacted soil or gravel. While gravel is an optional material, it helps with drainage. Some contractors also recommend installing a weed control membrane, which helps provide a solid foundation for the frame. In the case of an elevated deck, a pro will often lay down a concrete slab as a foundation. 

When deciding if you should use 2x6 or 2x8 deck joists, consider the size of the deck, joist spacing, and materials. Larger decks, larger-spaced joists, and weaker wood all require more support, meaning they need larger joists. For example, 2x8 redwood joists spaced 16 inches apart can only safely span up to 10 feet and 7 inches. On the other hand, 2x10 southern pine joists spaced 12 inches apart can be as big as 16 feet and 2 inches. If you aren’t sure what size joist is best for your project, speak with your deck builder.

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.