Prepare Your Lumber
Cut all lumber to the proper dimensions -- eight 2-by-4-inch pieces 28 inches long, two 2-by-4-inch pieces 36 inches long, and eight 1-by-6-inch slats 79 inches long. These measurements are for a full-size futon mattress. Adjust the dimensions to suit the size of the mattress.
Drill one hole through each of your wooden beams. Use a drill bit the same diameter as your lag bolts. Place the hole on the center line of the beam, 1 inch from one end.
Drill a second hole on the opposite end of two of your wooden beams, also placed on the center line, 1 inch from that end.
Sand all faces of your lumber until the wood is smooth enough to run a finger across without feeling any burrs or ridges.
Paint all faces of your lumber. This makes the frame more attractive, and it protects your mattress from wearing against the wood. Allow it to dry completely, and add a second coat.
Pair off your 28-inch beams and attach them by passing a lag bolt through the holes and tightening down the wing nut. Make sure the two beams with two holes in them are not attached to each other.
Set the beams on the ground, parallel and with their ends aligned. They should lie straight, instead of bending at the joint. Confirm that the two beams with an extra hole have the hole on the same side, and are the beams at the outside edge of the arranged beams.
Space the beams. The outside edges of the outside beams should be approximately 76 inches apart. The inside beams should be spaced evenly, each about 20 inches from the nearest outside beam.
Lay your slats perpendicular to the beams, evenly spaced with one beam lying with its outside edge along the ends of each set of beams. Lay them with about 1 inch of space between each slat, with a gap over the point where you've bolted the beams together.
Screw the slats into position, using two wood screws at each point where the slats cross a beam. Drill through the slat and into the end of the beam beneath.
Attach the 36-inch beams to the beams with the extra holes using the remaining bolts and wing nuts. Align them so they are on the interior faces of the beams.
Touch up any scuffs in the paint that occurred during construction. Allow it to dry, and add your futon mattress.
Things You Will Need
- 8 wooden beams, 2-by-4-by-28 inches
- 2 wooden beams, 2-by-4-by-36 inches
- 8 wooden slats, 1-by-6-by-79 inches
- Power saw
- Paint or stain
- Power drill
- Wood screws, 2 inches long
- 6 lag bolts, 5 inches long
- 6 wing nuts
- You fold this frame by loosening the wing nuts and pulling the side with the extra beams up to form the back of your couch seat. Pull the extra beams outward to support the back by bracing against the floor.