How to Build a Deck Bench

Learning how to build a deck bench is a good way to add seating to your deck without much cost or effort. Building a deck bench requires a few basic tools, supplies and carpentry skills. With these, you could be sitting pretty by the end of a weekend.

Understanding How To Build A Deck Bench

• Anatomy of a bench. A deck bench is a simple piece of furniture that helps to define the edges of your deck and provides extra casual seating. The basic elements of a deck bench are the support legs (that raise the bench and may be attached to the deck frame) and the seat (built of sturdy two-inch thick wood members). Optional elements include armrests and seat backs.
• Basic proportions. The average seat is positioned 16" to 18" off the floor and has a depth of 15" to 18". The length of your bench will depend on the configuration of your deck edges, but you should plan to have support legs positioned every 36" to 48" along the length of your seat.
• Backless designs. Most deck benches are designed without seat backs. There are two reasons for this design decision: most deck have rails that may serve as seat backs and putting a seat back on a deck bench would block the view from the deck. If you plan to have a seat back, the average angle is between 10 and 15 degrees.
• A word on materials. Cedar, redwood and pressure treated pine are the most popular choices for deck bench wood, but your choice of wood should match the wood used to build your deck if at all possible. All fasteners should be of hot dipped galvanized construction to resist rusting. You'll get a tighter and stronger bond using screws or bolts than you will with traditional nails.
• A bit of support. The support legs of your deck bench can be fixed to he deck frame or independent of the deck construction. If you choose to attach the bench to the deck frame, try to add the support legs at the time of deck construction. If you are unable to add the support legs at construction time, you'll need to remove, modify and replace some of the existing decking when the support legs are installed.

A Simple Deck Bench

• Materials. The following movable deck bench is made from 4" x 4" and 2" x 6" lumber. An 8' long bench will require fewer cuts as the seat elements can be used without cutting. Galvanized lag bolts and decking screws are used to attach the elements of the bench.
• Support legs. Cut the 4" x 4" lumber into six 17-3/4" sections and six 9" sections. Lay the wood out into three boxes composed of two long sections and two short sections. The long sections should be laid out vertically and the short sections should fit horizontally between the long sections. Connect the long and short sections using 6" lag screws through the long sections into the short sections. For comfort and safety, countersink the screw heads 1/2" into the wood surface.
• Bench seat. Next, mark a centerline on each of the three seat elements. Set the three support leg structures upright on a flat surface and lay a seat board across the support structures. Using a seat board as a guide, position the support legs so that one is centered in the middle of the seat board and the other two are flush with the ends of the support legs. Using deck screws, attach the first seat board flush with the front edges of the support legs. Attach the second seat board flush to with the back edges of the support legs. Attach the final seat board centered between the first two seat boards, leaving a 1/4" gap between all seat boards.