Waterbed frames are made of wood or metal. Before you buy materials, determine the dimensions of the mattress and use it to calculate the size of the frame. Make sure the wood or metal is strong enough to support the filled mattress [source: Waterbed Frames].

We'll show you how to build a wood frame for an 80-by-60-by-6-inch mattress. If your mattress size differs, adjust the dimensions accordingly. Here's what you'll need:

  • C clamps
  • Drill and countersink bit
  • Hammer
  • Wood glue
  • One 86-by-66-inch (2.18-by-1.68-meter) baseboard, at least ½-inch (1.27-centimeter) thick
  • Two 86-by-3-by-6½-inch boards for side rails
  • Two 60-by-3-by-6½-inch boards for end rails
  • Eight 6-by-¼-inch dowels
  • 2-inch wood screws

Let's build the waterbed frame:

  1. Drill holes along the baseboard 1½ inches (3.81 centimeters) from each edge and spaced 7½ inches (19.1 centimeters) apart.
  2. Ream each hole with the countersink bit until the tops of the wood screws sit flush with the top of the baseboard.
  3. Stand all four rails on their side edges and position them to form a rectangle.
  4. Draw a line along the center of each side rail's end edge. Draw cross lines two and four inches (5.1 and 10.2 centimeters) along the edge.
  5. Cut a shallow groove along the length of each dowel.
  6. Clamp each side rail to the edge of each end rail so that the end rail covers the edge of the side rail.
  7. Mark each rail pair so you can put them together after drilling holes.
  8. Drill a 6-inch (15.2-centimeter) deep hole at each cross mark, going through the side rail and into the end rail.
  9. Coat the dowels with glue and tap them into the holes.
  10. Apply a coat of glue along the top edge of each rail.
  11. Place the baseboard on the frame so its edges are even with the frame edges. Clamp the baseboard to the frame.
  12. Fasten the base to the frame with the wood screws. Make sure the tops of the screws are flush with the baseboard.
  13. Wipe away any excess glue and allow it to dry.
  14. Turn the frame over and install the water mattress [source: Building the Waterbed Frame].