How to Build an Outdoor Bench Seat - Outdoor Cabinets

Building an outdoor bench seat can be a fun and rewarding DIY project. With the right materials, tools, and techniques, you can create a customized bench perfect for your patio, deck, or garden. This comprehensive guide will walk you through the entire process, from planning and design to assembly and finishing. Follow along to learn how to build your own durable, comfy outdoor bench seat.

Planning Your Outdoor Bench Seat

Before you start building, take some time to think about your design. With smart planning upfront, your project will go smoother and your finished bench will better suit your needs.

Determine the Size

How big do you want your outdoor bench to be? Standard bench seats are 4-6 feet long. Make sure to measure the intended space for the bench and design the size accordingly. If you’ll use the bench solo, a 4 foot length could work. For seating two people, 5-6 feet is better. You can always adjust the length during building if needed.

Choose a Style

There are a few common outdoor bench styles to consider:

Traditional – Simple, classic look with straight legs and armrests.
Rustic – Made from unfinished logs or planks for a natural vibe.
Modern – Clean, straight lines for a sleek, contemporary look.
Curved – Gentle arch shape on the seat, legs, or backrest.

Think about the overall aesthetic you want and your DIY skills to select a style. Traditional and rustic designs are beginner-friendly. Modern may require more precise construction.

Decide on Features

Consider any extra features you may want:

Backrest – Provides lumbar support. Can be full-length or just a short center panel.
Armrests – Comfortable spot to rest your arms. Also helps contain seat cushions.
Storage – Liftable seat to store items inside the bench frame.
Plant pots – Built-in planters on sides or back for greenery.

The more complex the features, the more challenging the build will be. Keep it simple, especially for your first bench. You can always add upgrades later.

Choose Materials

Outdoor benches are commonly made using these materials:

Cedar – Naturally weather-resistant softwood. Ages to silvery gray.
Redwood – Also naturally durable. Ranges from pinkish-red to deep brown.
Teak – Tropical hardwood that holds up to weather. Rich brown color.
PVC – Weatherproof synthetic lumber. Looks similar to painted wood.
Aluminum – Won’t rot or rust. Requires no finish.

Cedar and redwood are attractive classic choices. PVC and aluminum work well for low-maintenance designs. Teak has exceptional longevity but is expensive.

Determine Your Finish

You’ll need to protect any exposed wood from moisture damage. Options include:

Paint/stain – Adds color and seals the wood. Requires periodic recoating.
Clear wood sealant – Preserves natural color while waterproofing. Also needs reapplication every 1-2 years.
Outdoor oil – Soaks into wood and resists UV rays/water. 1-2 annual coats.
Varnish – Clear glossy coating for a smooth protective layer. Recoats every year or two.

Factor in the ongoing maintenance required when choosing a finish. Outdoor oil is easiest as it just needs occasional renewal coating with no sanding or stripping.

Sketch Your Design

Draw up a simple plan for your bench on paper. Include the size, style, materials, and any accessories like backrests or armrests. This will serve as your guide during construction. Adjust the sketch as needed if you make changes once you begin the build.

Gather Your Materials and Tools

With your bench design complete, it’s time to gather everything you’ll need for the project.

Lumber

Purchase your lumber according to the type and sizes required per your plan. For a basic 6 foot bench, you may need:

2 x 6 boards for the legs – 4 pieces at 36″ length
2 x 10 board for the seat – 1 piece at 72″ length
1 x 6 boards for supports – 2 pieces at 30″ length

Measure precisely and get help loading long boards if needed. Avoid warped, cracked or twisted lumber.

Hardware

You’ll need an assortment of hardware:

Exterior wood screws (2-3″ and 3-4″)
Exterior wood glue
Lag bolts with washers
Corner braces for reinforcement

Use corrosion resistant hardware designed for outdoor use.

Tools

These basic tools will come in handy for building your bench:

Circular or miter saw – cut lumber
Power drill/driver – drive screws
Tape measure
Level
Carpenter’s square
Sandpaper – 80 and 120 grit
Safety gear – glasses, ear protection, gloves

Rent or borrow any tools you don’t already own. You’ll also need paint, stain, or other finishing supplies once construction is complete.

Construct the Bench Frame

With your materials and tools gathered, it’s time to start building. Constructing a sturdy frame is the first crucial step.

Cut the Legs

Mark cutting lines on your 4 leg boards based on the height you want for the bench seat. Standard seat height is 17-18″.
Cut the legs to length using a power miter or circular saw. Cut ends should be straight and square.
Sand off any splinters, rough edges, or saw marks on the cut legs.

Repeat to cut all 4 legs to identical lengths. Deburr the ends and sand smooth.

Attach the Side Supports

The side supports will join the front and back leg pairs to form the side frames.

Position 2 legs parallel, with inside edges aligned. Space based on desired bench width.
Place a side support board across the tops of the legs.
Drill pilot holes and drive 3″ exterior screws through the support into the legs.
Attach the support as close to the top of legs as possible for maximum strength.
Repeat for the second side frame with the remaining 2 legs and support board.

Install the Seat Supports

Now to add the lengthwise supports for the seat:

Flip one side frame upside down and rest the frame edges on spacers.
Mark where the seat supports will attach near the bottom of the legs.
Attach the supports at the marks using exterior screws driven into the legs.

Complete the same support installation on the remaining side frame.

Join the Side Frames

Stand the side frames upright with the leg bottoms flat on the floor.
Position the frames parallel to each other at the desired bench width.
Measure diagonally from opposite corners to ensure the frames are square.
Draw the frames together until the side supports meet tightly.
Drill pilot holes and drive 3-4″ lag bolts through the supports into the legs.

The connected frames will now form a rigid base for your bench.

Add the Seat

Now you can attach the seat itself to complete the main bench structure.

Cut and Shape the Seat

Cut the 2×10 seat board to your planned length according to the frame size.
Sand the top and bottom surfaces to smooth any rough areas.
Round over the front edge of the board using a router or rasp. This eases pressure on the back of your legs when sitting.
Seal the cut ends and sanded surfaces with clear wood sealer. Let dry completely.

Install the Seat

Center the seat board on top of the support boards.
Drill pilot holes down through the seat into the supports below.
Drive 3″ screws into the supports to secure the seat. Don’t overtighten.
The seat should overhang the front and rear supports by 2-3″ on each end.

With the seat installed, your bench frame and sitting surface are complete!

Add Optional Backrest

If you want a backrest for added comfort, attach a center panel now before moving on to accessories.

Cut the Backrest Panel

Use 1x or 2x lumber to cut the backrest width equal to the seat.
Cut length based on your desired backrest height. 10-14″ high is typical.
Sand and finish the sawn edges as you did for the seat board.

Install the Backrest

Center the backrest board vertically against the rear legs.
Drill pilot holes and drive screws through the board into the legs.
Use at least 3 attachment points top, bottom, and middle.
Check it’s positioned square before screwing into place.

The backrest will make your bench much more supportive and comfy.

Attach Armrests

Armrests add comfort while also retaining seat cushions. Follow these steps to add them to your bench:

Cut the Armrest Boards

Cut 2 boards to the same length as your overall bench width.
Rip the boards to 4-5″ wide using a table saw or circular saw.
Sand smooth and round over the edges. Apply protective sealer.

Install the Armrests

Center an armrest board on the front legs, with overhang at each end.
Drill pilot holes at an angle down through the board.
Drive screws into the legs to secure the armrest.
Repeat to mount the second armrest at the same height on the rear legs.

Now you can comfortably rest your arms when relaxing on your bench!

Add Decorative Touches

Apply some creative finishes to give your DIY bench seat even more character and charm.

Sand and Seal the Wood

Sand all wood surfaces with 80 grit paper to prep for sealing.
Wipe away sanding dust.
Apply 2-3 coats of clear outdoor wood sealant, allowing it to dry between coats.

This will protect the wood while showing off the natural grain.

Paint or Stain the Bench

For color, apply exterior paint or stain over the sealant:

Lightly sand to help paint adhere to the sealant.
Wipe and dry all surfaces completely.
Apply at least 2 coats of exterior latex paint or oil-based stain.
Let dry fully and cure for several days before using.

Choose a color to complement your outdoor space.

Add Decor Details

Personalize with accents like these:

Stencil shapes or patterns onto the backrest.
Use exterior wood glue to attach decorative trim pieces.
Inlay tile, shells, or pebbles into the seat or legs.
Attach brackets under the seat for flower pots.
Use colorful outdoor cushions and throw pillows.

Apply Protective Finish

Once any paint or stain has fully cured, apply a clear outdoor polyurethane or spar varnish.
This adds extra protection from weathering.
Choose satin or gloss sheen for easier cleaning.
Add 2-3 thin coats, sanding lightly between each.

Maintaining and Repairing Your Bench

With proper care, a high-quality wood bench can last 5 years or longer outside. Here are some tips for longevity:

Inspect regularly for any damage, wear or mold growth. Address issues right away.
Each year, sand and reapply exterior wood finish to protect from moisture.
Check hardware screws/bolts and retighten if any become loose over time.
Keep the bench clean by sweeping off dirt and debris regularly.
Cover the bench when not in use for extended periods.
Store cushions or other accessories indoors when not needed.
Repair cracked wood using waterproof wood filler and refinish.
Replace rotted or split boards as soon as possible to prevent further damage.

With regular maintenance and care, your handcrafted bench will stay beautiful and provide a comfortable resting spot in your outdoor living space for years of enjoyment.

Frequently Asked Questions

What type of wood is best for an outdoor bench?

Cedar and redwood are excellent choices because they naturally resist decay and insects. Teak is also very durable but is more expensive. Pressure-treated lumber adds weather resistance to less expensive woods like pine.

What tools do I need to build a bench?

A miter or circular saw, jigsaw, power drill, and sander are the essential tools. A router, biscuit joiner, or pocket hole jig can help with more advanced joints. Have safety gear like glasses, ear protection, gloves, etc.

How deep should I sink the legs into the ground?

Dig holes 12-18 inches deep and place a few inches of gravel in the bottom. Position the legs and backfill with concrete to just below ground level. This prevents standing water around the legs.

Can I build the bench with natural tree logs?

Yes, you can use untreated tree branches and small logs. Debark them and dry the wood for at least 6 months first. Apply a protective oil finish and expect a more rustic look as the wood ages.

What is the best way to attach the backrest?

Use exterior screws driven at angles through the backrest into the rear legs. For a sturdier option, cut notches in the legs to hold the backrest and attach with wood glue and screws.

My bench feels wobbly. How can I reinforce it?

Check that all screws and bolts are tight. Consider adding corner braces or triangular knee braces under the seat for more rigidity. Sistering additional wood to the legs can also help strengthen a shaky bench.

Conclusion

Building your own outdoor bench seat is an extremely rewarding weekend project. Follow the techniques outlined in this guide, and you’ll have a customized bench that provides comfort and charm in your outdoor living space for years. Be sure to choose weather-resistant materials and construction methods meant to withstand the elements. The effort is well worth it to have durable, relaxing bench seating that you crafted yourself. So grab your tools, pick a design, and get ready to create the perfect backyard bench!