How to Make Plastic Lumber Lawn Furniture

Create leg assemblies. Place one upper support horizontally on work table. Lay one front leg on top of the upper support at the left corner perpendicular to it (use the square) and join with two screws. Lay one back leg on top of and perpendicular to the right corner and join with two screws. Flip so the legs are underneath. Measure 8 inches up from the bottom of each leg and mark. Lay one of the lower leg supports across the two legs with the bottom edge lined up with the 8-inch marks. Secure with two screws on each side. Repeat to make the second leg assembly.

Join the leg assemblies with the back and front cross members. Prop the leg assemblies upright with the supports facing each other, 23 inches apart. Place one rear cross member horizontally between the two leg assemblies and hold to the left corner of the left leg. Secure to the leg with two screws. Repeat on the opposite side. Measure 8 inches up from the bottom of each leg and mark. Attach the bottom cross member in the same fashion as the top with the bottom edge line up with the 8-inch mark. Rotate chair to the front end and measure 8 inches up from the bottom of both legs and mark. Attach the front cross member in the same manner as the back members with the bottom edge lined up with the 8-inch marks.

Attach the seat slats. Measure 2 inches forward from the back of the inside of the chair fame and mark on the top face of both lower leg supports. Lay one seat slat across the chair with the back edge lined up with the 2-inch marks and rest it on the lips formed on either side by the lower leg supports. Hammer to the lips on both sides with two nails, size 6 d. Attach the second slat with 1/2 inch of space between the first and repeat with the other two slats. The front slat will hang over the front cross member 1 1/2 to 2 inches.

Attach the armrests. Face the outside of the right leg assembly. Place one arm rest on top of the leg assembly with the inside edge flush with the upper cross member and 1 1/2-inches of armrest extending past the right and left side of leg assembly. Nail in place through the top of the armrest with six evenly spaced 8 d nails. Repeat on the left side.

Assemble the seat back. Lay the three back slats on the worktable with the ends lined up. Separate each slat with 1/2 inch of space. Measure 4 inches up from the bottom of the slats and mark. Place one seat back cleat across the boards with the bottom edge lined up with the 4-inch marks. Screw in place with two screws for each slat. Measure 12 inches up from the bottom of the slats and mark. Place the other seat back cleat across the board with the bottom edge lined up with the 12-inch marks. Screw in place, two screws per slat.

Attach the seat back to the chair. Stand behind the chair and hold the seat back upright with the cleats facing you. Lift the seat back over the back cross members. Tilt the bottom edge toward you and slide it into the space between the rear seat slat the lower cross member until the bottom of the bottom cleat locks onto the top of the lower cross member. Tilt the top of the seat back toward you until the bottom of the top cleat locks over the upper cross member and the seat back stays in place. Face the front of the chair. Screw the seat back to both cross members with two screws per slat.

Round the edges of the boards with the router.