Folding sofa beds function as couches, as well as a bed. They work well in dorm rooms, camps and cabins. Guests will be pleased to sleep on a folding sofa bed rather than a blow-up mattress, or sleeping pad. Building a sofa bed is an easy task requiring some basic carpentry knowledge.
Position two 28-inch boards on their 2-inch-wide sides, parallel, and 41 inches apart. Lay seven 60-inch boards perpendicularly on top of the two boards so their ends overhang the sides of the 28-inch boards by eight inches on each side. Space the boards 1/2 inch apart. Screw the 60-inch boards to the 28-inch boards using four screws for each 60-inch board. Repeat this step to complete two-thirds of your folding sofa frame. These are the outside frames. The measurements might seem off, but standard pine lumber, such as 1-by-4-boards actually equal 1/2-by-3 1/2-inches. The 1-by-4-inch label, is the nominal size, not the actual size. This is true for all store bought construction lumber.
Position two 28-inch boards on edge, parallel, and 44 inches apart. Lay the last seven 60-inch boards perpendicularly on top of the two boards so their ends hang 6 ½ inches over each side of the 28-inch boards. Space the boards ½ inch apart, and screw them down as you did in the last step. This is your middle frame.
Set the middle frame next to one of the first frames. The outside 60-inch board of the middle frame should be 1/8 inch away from one of the outside 60-inch boards on the other frame. The ends of the 60-inch boards on both frames must be aligned, and on top of the 28-inch boards.
Connect the frames by screwing two hinges to the 60-inch boards on each of the frames. The pin in the hinges should rest inside of the 1/8-inch gap, with the hinges positioned eight inches away from both ends of the 60-inch boards.
Turn both of the connected frames upside-down so they rest on the 60-inch boards. Lay the last frame upside-down and next to the middle frame. It should be position exactly like the first two frames were positioned together. Connect these frames together with the last two hinges just as you did in the last step, but on the opposite side of the 60-inch boards.
Turn your frame over so it is resting on the 28-inch boards. This is the bed position. Lift up the two frames that were connected last so they are perpendicular to the floor. Set your futon mattress on the frame, and fold a third of it underneath itself so it rests on the first frame. This is the sofa position.