DIY Folding Sofabed

Stand the 28-inch planks on their 2-inch sides, 40-inches apart and hold them in place upright with bricks.

Lay a 60-inch pine plank across the upright 28-inch planks, flush with the top edges and overhanging equally on each side of the 28-inch planks. The overhangs should each total approximately 7 1/2-inches. Attach the 60-inch plank using wood screws.

Measure a space of 1/2 an inch past the edge of the 60-inch plank and place another 60-inch plank across the 28-inch planks, parallel to the original 60-inch plank. Attach to the 28-inch planks using wood screws. Repeat the process with five more 60-inch planks.

Create a structure identical to the one you just constructed. The two structures are the outside frames of the sofabed.

Lay two 28-inch planks on their 2-inch sides, 44-inches apart. Attach seven 60-inch planks to the top edges of the 28-inch planks, leaving a 6 1/2-inch overage on either side of the 28-inch planks and spacing the top boards 1/2 of an inch apart. Use wood screws to secure the planks. This structure is the center frame of the sofabed.

Place the center frame next to an outside frame, aligning the outsides of the 60-inch planks on one side of each structure. Place the other outside frame opposite to its matching frame on the other side of the center frame.

Attach an outer frames to the center frame using the metal hinges. Fold the hinge between the frames and approximately 8 inches from each of the ends of the 60-inch planks. Screw in the hinges with wood screws.

Flip over the attached frames and lay the last outer frame on top. Attach this frame to the structure using hinges and wood screws. The final structure should form the shape of a letter "Z" when completed.

Turn the completed frame over and lay the mattress on top of the 28-inch planks. Use it flat as a bed or, with one-third of the frame and mattress folded under, as a sofa.