Create a Room
Consider creating an outdoor room if there is at least 9 feet of clearance beneath the deck. Run electricity below the decking to provide overhead lighting and ceiling fans. Purchase an under-deck ceiling system that will cover the bottom of the deck. These systems are specifically made to provide drainage for any rainwater that seeps through the deck as well as cover any electrical wires. Install decorative pillars to give a cosmetic lift to the deck posts, or consider using ivy or other climbing plant to cover the posts. The flooring can be poured concrete, brick, flagstone or slate. Leave the room open or build partial walls. Screen can be used in lieu of walls to keep bugs out. Think about putting in some kitchen amenities such as a built-in grill, small refrigerator and sink if the area will be used for eating and entertaining.
Convert the space below the deck into a play area, for or clubhouse if you have children. Hang tire swings from deck beams, paint a colorful mural on the wall or put in a sandbox for the very young. Select a theme that reflects the children's interests such as tropical beach, sports, dinosaurs or the rainforest. Use different types of ground covering, such as different colors of mulch, gravel or outdoor carpet, to create distinct areas within the space.
Convert under-deck spaces that have just a few feet of clearance into storage space. Before starting, lay down landscape fabric to stop weeds and grass from growing. Wooden lattice is available in a variety of finishes and patterns. Lattice sheets are usually 4 by 8 feet. Install some non-load-bearing posts at 4-foot intervals around the deck to secure the lattice if the deck posts are more than 4 feet apart. Measure the height from the bottom of the deck to the ground and cut the sheets accordingly. Screw or nail the lattice into posts and the deck bottom, continuing around the deck until the space is enclosed. Leave a small entryway for easy access or use hinges to make a small door out of one sheet of lattice. Plant small bushes or flowers along the bottom of the lattice to make the space more visually appealing.