- Use the measuring tape to measure the height of your mattress and the depth of your waterbed frame. If your mattress is taller than the frame is deep, then you should be able to simply put the mattress in and enjoy. If the mattress is shorter than the depth of the frame, you'll need to insert the platform.
- Subtract the height of your mattress from the depth of your frame.
- Cut all four wooden strips to a thickness equal to the difference between mattress and frame. Cut the length of two strips to match the width of your mattress. Cut the other two to match the length, minus two inches.
- Apply a coat of wood glue to one wide face of each wooden strip. Place them in the corners of the water bed frame, resting on the 1-inch thick faces.. Allow to dry.
- Set the plywood sheet in place, creating a "false bottom" by resting on the edges of the wood strips.
- Set your mattress in place. It should protrude half an inch above the top of the retaining planks.
How to Convert a Waterbed Into a Conventional Bed
Water bed frames are nice. They're made of attractive wood and many come complete with shelves and drawers. They're built to hold up more than half a ton of weight. Converting one to accommodate a conventional mattress can make for an attractive and utilitarian piece of bedroom furniture. The trouble with this conversion comes from the retaining planks, the short walls built to keep the reservoir from flopping over the edges. If your mattress is too short, it's easy to bark your shins on them climbing into and out of bed. Fortunately, a platform at the bottom of the well can convert the frame to fit any mattress style.