Get matched with top deck maintenance specialists in Madisonville, LA

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.

What goes under your floating deck depends on your preferences. Some homeowners put landscaping fabric underneath their decks to prevent weeds from popping up through the boards. Others choose to build a floating deck over grass or gravel. However, it’s best not to set your deck directly on the ground. Instead, set your deck on blocks to keep it elevated enough to prevent moisture from rotting the wood.

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.