Measure the distance between the underside of your mattress and the floor.
Cut your beams so that they are both as wide as the distance measured earlier. You can save money by waiting to buy them until after you've completed the measuring. That way you won't buy a 10-inch wide beam when a 7-inch beam will do.
Find the center of the 80-inch beam. Cut a notch in the 2-inch wide side using your power saw. Cut the notch 1-1/2-inches wide and half as deep as the beam is wide. Repeat this with the 76-inch beam.
Slide the two beams together in a cross shape, nesting them at the notch like a pair of Lincoln Log toys.
Slide the cross underneath your mattress. Depending on the structure of your frame, you may need to lift the bed and set it down on top the support beams.
Things You Will Need
- Measuring tape
- Wooden beam, 2 inches by 80 inches
- Wooden beam, 2 inches by 76 inches
- Power saw
- The dimensions given here are for a standard king mattress. California king mattresses need beams that are 72-inches and 84-inches long, respectively.