DIY Concrete Garden Bench

Cut all the boards to length.

Lay the 36-inch long boards on edge and parallel to one another on a flat work bench.

Place an 18-inch board between the longer boards at each end to form a rectangle measuring 19-1/2 by 36-inches on the outside.

Screw the boards together at the corners with 1-1/2-inch wood screws, using two screws per corner.

Place the piece of hardboard -- smooth side down -- on top the rectangle and fasten it in place with 5/8-inch screws every 6 to 8 inches around the perimeter.

Turn the finished box over on the flat workbench so the open side faces up, and place a carpenter's level across the width, then the length, to test for level. Adjust the box by sliding thin wedges of wood under the workbench legs if necessary, until the box sits level.

Cut #4 rebar to the indicated lengths.

Tie the rebar together using baling wire and pliers so the shorter bars cross the long bars near each end and in the center -- allowing about an inch of overlap on the ends of the short bars.

Use tin snips to cut a section of 1-inch chicken wire 16 by 34 inches.

Spread shortening or grease over the interior of the box to coat so the concrete releases when cured.

Place the rebar framework inside the box, propping it off the bottom with small rocks or pieces of brick under the crosspieces to support it about an inch above the floor of the box and 1 inch from each wall of the box.

Set the section of chicken wire on top of the rebar and tie it in place with a few pieces of wire, maintaining the 1-inch space from the sides.

Mix concrete according to manufacturer's directions and pour it slowly into the box from one corner to avoid trapping too many air bubbles, which may weaken the concrete. Pour it at least two inches thick for strength.

Trowel the surface to smooth, then cover with damp burlap and let set at least 24 hours to cure.

Unmold the concrete when fully cured by turning the box over and taking out the screws to disassemble the box.

Clear a 16- by 32-inch space in the area you want your bench to sit. Level the soil and tamp to firm it.

Stack two cement blocks, one atop the other on each end of the cleared and firmed space -- lining them up so that the long sides are parallel and they sit 18-inches apart, measured from the inside of one stack to the inside of the other.

Turn over the concrete slab, or bench seat, so the smooth side is facing up. Carefully lift it into place and rest it on top of the stacked blocks, adjusting everything as needed so that no more than 1 inch of the concrete seat protrudes beyond the blocks on any side. You may need a helper for this.