Starting at one end of the bed (perimeter line), measure along the border string line and make a mark at 10 1/2-feet and another at 20 1/2-feet using a permanent marker. These marks designate the location of the 2-inch by 4-inch board unions that form the bed frame.

Set concrete blocks directly under the marks on the string and at both ends 6 inches inside the perimeter lines.

Next, position the drilled 2-inch by 4-inch boards on the concrete blocks. The ends of the boards should join over the blocks. The 10 1/2 and the 9 1/2-foot-long boards should be oriented such that the ends with holes drilled 3 inches from the end are next to the perimeter lines. The 10-foot-long board should be in the middle.

	Connect the boards using 2-inch by 4-inch saddles and joint hanger nails.
	With the 2-inch by 4-inch frame section turned on edge, use wood shims to raise the elevation of the frame. Adjust the elevation so the top of the frame is even with the string line. Because the string line represents the outside surface of the bed, be sure to position the outer surface of the frame inside the string (towards the bed interior).