How to Build a Wood Box for Mattress Support

Position two 8-foot long 2-by-4-inch boards parallel on the floor. Set the boards with their 4-inch sides facing each other. Make the board ends flush. Create a distance of 4 feet between them.

Set a 4-foot 2-by-4-inch board between each end of the 8-foot boards. Have the 4-inch sides face each other. Position the boards so that the ends of the 4-foot boards butt against the interior face of the 8-foot boards. Make the ends flush, forming a rectangle. Drill a pair of screws through the exterior sides of the 8-foot boards into the ends of the 4-foot boards.

Place an “L” bracket against the inside corners of the rectangle. Drill screws through the bracket holes into the wood behind them. The brackets add strength to the wood while remaining hidden.

Measure a series of 2-foot lengths along the long sides of the frame. Mark the positions of the measurements. Put a 4-foot long 2-by-4-inch board at each pair of markings. Face these boards the same direction as the end boards. These are the middle supports for the mattress. Attach these boards to the frame as you did the first two 4-foot boards.

Lay a 4-by-8-foot sheet of 1-inch-thick plywood over the frame. Match up the sides of the plywood with the frame. Drill one screw per side per corner through the plywood into the frame. You will have two screws adjacent each other at the corners. Drill a screw through the plywood into the frame at 4-inch intervals between the corners on all sides. Use the same measurements to attach the plywood to the middle supports.

Sand the rough edges to the corners and any spots along the frame with medium grade sandpaper. Use a power sander for speed and uniformity. Paint the frame with your chosen color or stain.