Lay the four 3-foot landscape timbers side by side running parallel to form a rectangular shape 20 by 36 inches in size. Adjust the cut ends of the timbers so they are flush down the narrow sides.
Place a 20-inch timber over the rectangle of timbers so it runs across the width. Adjust the timber to run down the center of the rectangle. Drill four screws through this brace board and into each of the 3-foot boards below.
Lay a 20-inch board on the ground. Place two 20-inch boards perpendicular to it, one at each end, to form the legs of a “U” shaped unit. Drill through the two leg timbers and into the first 20-inch board to secure. Repeat this step with the remaining timbers to make a second “U” unit.
Stand the rectangular table top on one of its long sides with the brace board facing you. Bring the brace board of the “U” unit up to the underside of the table top with the legs turned toward the short edge of the top and the brace board running along the inside.
Screw down through each 3-foot board and into the “U” unit’s brace board to secure. Align and attach the second “U” unit to the other side of the table with the legs of the “U” facing outward to the other side. Stand the table upright when complete.