How to Make a Platform Bed Frame Out of an Old Waterbed

Remove the water-filled mattress, thermostat and liner. Discard or store the parts according to your needs.

Measure the recessed area where the waterbed mattress used to sit. Include the width, length and depth.

Cut blocks of wood that are 2 inches thick to fit in the mattress cavity across the width of the bed. Use a table saw or ask your lumber company to cut the wood for you. For example, if the bed is 6 feet wide and 10 inches deep, your blocks of wood should measure 2-by-10-by-72 inches. Cut enough pieces to place one block every 8 to 12 inches.

Fit the blocks of wood inside the waterbed frame. Screw the wood into the frame.

Lay two pieces of precut 1/2-inch plywood across the bed. The plywood sheets should cover the edges of the frames covering the blocks of wood and empty space the waterbed mattress used to occupy. Cut the plywood to size yourself with a table saw or ask your lumber provider to cut it to your specifications. Screw the plywood in place using the frame and blocks of wood.

Sand the plywood and edges for a smooth finish. Paint or stain the plywood and edges to match or complement the bed frame. Refinish the entire frame if you want a new look.

Position the mattress on top of the plywood as you would with any other platform bed.