Step-by-step: How to build an arbor with a bench
- Four 10' 4 x 4 posts
- Two 8' 2 x 6 beams
- One 12' 2 x 6 for three cross braces
- One 8' 2 x 6 for two seat supports and three back supports
- Two 8' 2 x 4s for four bench legs, back rail, and lattice support
- One 12' 2 x 8 for three seat planks
- One 8' 1 x 4 for two backrests
- One 4' 1 x 6 for two armrests
- Twelve 6' 2 x 2s for four verticals and eight slats
- One 4' x 4' lattice sheet, cut to 3' x 4'
- Four decorative corner braces
- 1⁄4" galvanized carriage bolts with nuts and washers: four at 31⁄2", eight at 5", four at 6"
- Twelve 1⁄4" x 4" galvanized lag screws with washers
- 11⁄4" and 3" decking or stainless-steel screws
- Exterior stain and sealer or primer and paint
Cut the ends of the 2 by 6 beams to a decorative profile. Seat the beams in the post notches and center them from side to side. Bolt the beams to the posts with two 5-inch carriage bolts at each joint.
Position each seat support beside a post with the top of the support 16½ inches above the ground and one end flush with the outside of the post. Drill a single ¼-inch hole through the post and the support, then bolt them together with a 6-inch carriage bolt. Adjust the support so it is level. Drill a ¼-inch hole and add a second carriage bolt.
Leave a slight gap between the planks for drainage. Attach the planks with 3-inch screws. Round the corners with a jigsaw, then use a router with a ½-inch roundover bit to round off the edges.
Align the back edge of the supports with the back of the seat and attach the supports to the post by drilling pilot holes and driving 3-inch screws. Attach the center back support by driving screws up through the seat from underneath.
Attach the second backrest between the top backrest and the seat.
Use a router equipped with a 3⁄8-inch roundover bit to round the edges, then sand any rough edges. Attach the armrests to the tops of the legs with 3-inch screws, aligning the inside edges of the armrests with the inside faces of the front legs.
Use a power miter saw or a circular saw to cut the ends of the 2 by 2 verticals and slats at a decorative angle. Using 3-inch screws, fasten the four verticals in place inside the cross braces on the side opposite the bench. Screw the eight slats on top of the beams. Screw the decorative corner braces in place. Finish the arbor with stain, or apply primer and paint.
Building a bench and arbor combo is in some ways less complicated than building a standalone bench. The arbor provides the structure, and the bench comes along for the ride with no complex angles or fancy joinery.