Cut 20 pieces of 2-by-4-inch boards to 17 1/2-inch lengths with a saw. Sand them with 120-grit sandpaper to remove any splinters.
Assemble four of the pieces into a rectangle. The sides will be sandwiched between the top and bottom, making the finished rectangle measure 17 1/2 inches wide and 20 1/2 inches tall. Clamp the boards together with bar clamps.
Drill two 1/16-inch pilot holes into each corner, and then screw the rectangle together with 3-inch wood screws.
Assemble four more rectangles following the same steps.
Cut five pieces of 2-by-4-inch boards to 5-foot lengths with a saw. Cut five more to 42-inch lengths.
Stand two rectangles on the ground, positioned five feet apart.
Lay the five longer boards on top of the rectangles to form a bench seat. Drill pilot holes through each board and into the rectangles beneath it, and then screw the bench together with 2 1/2-inch wood screws.
Position a third rectangle under the bench to act as a third leg, positioned 17 1/2 inches from one end of the bench. Screw it into place.
Assemble a smaller bench with two more rectangles and the 42-inch boards.
Position the two benches in an L-shape, with the end of the short bench up against the side of the long one. The short bench's legs should butt up against the end and middle legs of the long bench.
Screw the contacting legs of the two benches together with 3-inch wood screws, combining the two benches into one.
Things You Will Need
- 2-by-4-inch boards, 20 inches long (20)
- Bar clamps
- 3-inch wood screws
- 2-by-4-inch boards, 5 feet long (5)
- 2-by-4-inch boards, 42 inches long (5)
- 2 1/2-inch wood screws
- Adjust the lengths of the boards in step 5 to customize the bench as desired.