How to make a wooden outdoor bench with concrete legs

Creating a wooden outdoor bench with concrete legs is a great DIY project that combines the natural beauty of wood with the durability and stability of concrete. Below is a step-by-step guide on how to make this sturdy, stylish outdoor bench.

Materials Needed:

• Wood for the seat: You can use hardwood like cedar, oak, or teak for durability and resistance to outdoor conditions.
• Concrete mix: For making the legs.
• Rebar or metal rods: To reinforce the concrete legs.
• Wood screws: For attaching the wooden seat to the concrete legs.
• Wood finish or outdoor sealant: To protect the wood from the elements.
• Concrete mold: This can be a pre-made mold, or you can create one using plywood or plastic.
• Tools: Measuring tape, saw, drill, mixing tools for concrete, safety gloves, and a trowel.

Step 1: Design the Bench

Before starting, sketch out a design for the bench. A simple rectangular shape is common, but you can adjust dimensions based on your space. For a standard bench:

• Seat length: 4-6 feet.
• Seat depth: 18-20 inches.
• Seat height: 17-18 inches (standard bench height).

Step 2: Cut the Wood for the Seat

Cut the wood to the desired length and width for the bench seat. If you’re using multiple boards, lay them side by side, making sure they are flush and evenly spaced. You can attach the boards together using screws or wood dowels to make the seat more sturdy.

Step 3: Build the Concrete Legs Molds

To create the concrete legs, you will need molds. You can use plywood, plastic, or any material that can hold the shape of the leg while the concrete sets. A typical concrete bench leg might be rectangular, measuring about 12-16 inches wide and 16-18 inches high. You can customize the mold dimensions based on your design.

• Cut the plywood to create four sides of the mold.
• For each mold, cut two long sides, two short sides, and a bottom piece that will hold the concrete.

Assemble the mold by securing the pieces together with screws or nails.

Step 4: Reinforce the Concrete Legs with Rebar

Before pouring the concrete, add reinforcement inside the mold to ensure the legs have enough strength to support the weight of the bench. You can use rebar or metal rods for this. Cut the rebar to fit inside the mold and bend it to create a framework that will add stability.

• Insert the rebar inside the mold before pouring the concrete.
• Ensure the rebar is centered and suspended in the mold by using small pieces of scrap wood to hold it in place.

Step 5: Mix the Concrete

Follow the instructions on your concrete mix package to prepare the concrete. Make sure to mix it thoroughly to avoid dry patches or air bubbles.

Step 6: Pour the Concrete Into the Molds

Once the concrete is mixed, pour it into the mold, filling it completely. Tap the sides of the mold gently to release any air bubbles and ensure the concrete settles evenly around the rebar.

• Use a trowel or stick to smooth out the surface.
• Allow the concrete to set for 24-48 hours. Ensure it is fully cured before removing the molds.

Step 7: Remove the Molds and Smooth the Legs

Once the concrete has hardened, carefully remove the molds. You may need to use a hammer or screwdriver to gently pry the mold away from the concrete.

• If needed, smooth the edges of the legs using a sander or a piece of rough sandpaper.
• If any imperfections remain, you can fill them with additional concrete and smooth again.

Step 8: Prepare the Wood Seat

To protect the wood from outdoor elements, apply a suitable outdoor wood finish or sealant. This will help preserve the wood and prevent water damage.

If the seat consists of multiple planks, attach them securely together using wood screws or dowels, ensuring the boards are flush.

Step 9: Attach the Wooden Seat to the Concrete Legs

Now that the concrete legs are ready and the wooden seat is prepared, it’s time to assemble the bench. Place the concrete legs in their desired position, then align the wooden seat on top of the legs.

• Use wood screws to attach the wooden seat to the concrete legs, drilling through the wood and into the concrete.
• Make sure the seat is positioned securely and level.

Step 10: Final Touches

Once the bench is assembled, inspect it for stability. Tighten any loose screws and ensure that the seat is firmly attached to the concrete legs. Finally, apply a layer of wood sealant to the seat for extra protection against the elements.

Step 11: Curing and Finishing

Before using the bench, allow the wood and concrete to fully cure. Concrete may take several weeks to reach its full strength, so avoid heavy use for a while to ensure the bench remains stable.

Once the bench is fully cured, you can add cushions or throws for comfort if desired.

Building a wooden bench with concrete legs is a rewarding project that will provide you with a durable, long-lasting piece of outdoor furniture. The combination of concrete and wood ensures that the bench can withstand outdoor conditions while offering a natural aesthetic that complements any garden or patio.

For more woodworking projects and detailed plans, check out Ted’s Woodworking Course here.