You can design the bench around a cushion or have one made to measure. Call a local fabric store or design studio and find out if outdoor fabrics are available. Cut the pieces according to your specific design.
Attach the 2" x 6" front brackets 12 inches from the ground to the outside sides of the 4" x 4" front posts with 3-inch stainless steel screws. Repeat this step for the rear seat bracket on the 4" x 4" rear posts.
Raise the front posts and front seat support assembly. Then raise the rear posts and rear seat support assembly about three feet apart to create the depth for the bench.
Attach the 2" x 6" x 3' sides of the seat to the outside of the 4x4 posts. The entire assembly must be connected at this point. Four 4" x 4" corner posts standing and connected to each other by 2" x 6" seats 12 inches from the ground.
Start attaching the two 2" x 4" seat slat brackets to the inside of the front and rear seat support pieces. They should be recessed 1-1/2 inches inside the seat supports so that when the seat slats are in place, the seat slates are even with the top of the seat support pieces. Attach the pieces with several stainless steel screws. These pieces support the cushion. Attach 2" x 2" seat slats every six inches and screw in the seat salt support pieces with 2" stainless steel screws.
Attach the 2" x 4" x 3' armrests to the 4" x 4" posts about 18" above the seat support deck. This may vary depending on the depth of the cushion. Using the 3" screws , attach the armrests to the inside of the posts.
There are two options for securing the top rails to the 4" x 4" posts.
Option 1:Cut notch in the rails and cut a notch or hole in the posts. Insert the notch into the mortise using glue, screws, and a clamp.
Option 2:Attach the cross pieces to the posts with a screw to the inside or outside of the 4x4 posts.
Attach caps to 4" x 4" posts and clamp in place.
Using a semi-transparent penetrating stain, brush a thin layer of stain onto the bench and allow to dry.
