What's inside
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A folding picnic bench is a useful first summer woodworking project: it has straight cuts, repeated parts, and no complicated joinery. This plan makes a 48-inch-long bench with a 12-inch-wide slatted seat. It folds to roughly 48 by 12 by 5 inches, fits in a car trunk, and seats two adults comfortably or three children.
The design uses two folding trestle leg frames connected under a slatted top. A pair of hinges lets each leg frame swing inward for storage. It is not intended as a permanent outdoor table or for standing on. Build it from straight, dry stock and test it on level ground before putting weight on it.
Contents
Materials and tools
Use four 8-foot 2x4s for the legs and supports, plus one 8-foot 1×6 and one 6-foot 1×6 for the seat slats. Actual 2×4 dimensions are about 1-1/2 by 3-1/2 inches, and 1×6 boards are about 3/4 by 5-1/2 inches. Choose cedar if the bench will live outdoors, or construction-grade pine if it will be stored under cover. Pine is cheaper and fine for a seasonal bench, but it dents more easily and needs better sealing.
You will also need four 3-inch exterior screws, about 24 1-1/4-inch exterior screws, four 3-inch strap hinges, four 2-1/2-inch gate or utility hinges, two folding leg braces or locking stays, exterior wood glue, sandpaper, and an outdoor finish. A set of exterior wood screws is useful because ordinary interior screws can rust and leave black stains.
Required tools are a tape measure, pencil, square, drill and bits, circular saw, clamps, and a sander. A folding workbench is convenient but not necessary; two sturdy sawhorses work just as well.
Cut list and layout
| Part | Quantity | Finished length | Purpose |
|---|---|---|---|
| Seat slats | 4 | 48 inches | Top surface |
| Legs | 4 | 29-1/2 inches | Two folding A-frame pairs |
| Long seat supports | 2 | 45 inches | Support slats beneath the seat |
| Cross braces | 2 | 18 inches | Stiffen each leg frame |
| End cleats | 2 | 9-1/2 inches | Keep slats aligned |
The 29-1/2-inch leg length produces a seat height close to 17 inches after the seat boards are added. Mark every cut with a square. Small errors multiply when four legs must fold together, so do not measure the second part from memory. Clamp the first leg on top of the next board and use it as a template.
Build the folding leg frames
Make one frame at a time. Lay two legs on a flat surface so their top ends are 9-1/2 inches apart and their bottom ends are about 27 inches apart. The legs should flare outward. Place an 18-inch cross brace between them, about 10 inches above the floor, and fasten it with glue and two 3-inch screws at each end. Pre-drill near the board edges to prevent splitting.
Repeat for the second frame, then check that both frames are identical. The most common beginner failure is a frame that rocks because the legs are different lengths or the brace is not square. Set each frame upright and measure diagonally from the floor to the opposite top corner. Adjust it before the glue sets.
Attach one 45-inch seat support to the inside of each frame, with its top edge flush with the top of the legs. Use two 3-inch screws through the support into each leg. Keep the supports on opposite sides so the frames can fold without hitting each other. Do not glue the hinges or moving parts.
Attach the seat slats
Place the two frames upright and parallel, with about 34 inches between their outside faces. Lay the four 48-inch seat slats across the supports. Leave a 1/4-inch gap between boards for rainwater and dirt. A scrap of 1/4-inch plywood makes a consistent spacer.
Center the slats so they overhang each end by about 1-1/2 inches. Drill two pilot holes through each slat at every support, then drive 1-1/4-inch exterior screws. Keep the screw heads slightly below the surface, but do not countersink deeply enough to create water-holding pockets.
Install the two 9-1/2-inch end cleats across the underside of the slats, one near each end. Screw them to the slats, not to the folding legs. These cleats keep the seat boards aligned while allowing the leg frames to move independently.
Install hinges and folding locks
With the bench upside down, mount two strap hinges between each leg frame and its seat support. Position the hinges about 6 inches in from the ends. The hinge barrels must face outward and remain clear of the seat cleats. Open and close each frame before installing the remaining screws.
Add a locking stay or folding leg brace to each frame. The brace should lock straight when the legs are open and fold inward when released. A locking folding-leg bracket is easier for a beginner than fabricating a wooden latch. Choose hardware rated for furniture or table legs, not lightweight cabinet hardware.
Never rely on friction alone to hold the legs open. If the bench shifts when you push sideways on the seat, stop using it and adjust the braces or add a second locking point. A folding bench that collapses unexpectedly can cause more injury than a stationary one.
Sand, finish, and test
Sand all edges with 120-grit paper, then finish with 180 grit. Round the front seat edges slightly; sharp 2×4 corners catch clothing and feel uncomfortable. Apply two thin coats of exterior penetrating oil or outdoor water-repellent finish, sanding lightly between coats. A clear exterior wood finish preserves the natural look, while opaque exterior paint offers better protection from sunlight.
| Finish choice | Best for | Trade-off |
|---|---|---|
| Exterior paint | Maximum color and UV protection | Needs careful coverage and touch-ups when it chips |
| Penetrating oil | Quick seasonal maintenance | Usually needs reapplication every year |
| Clear varnish | Furniture kept under cover | Can peel outdoors when water gets underneath |
Let the finish cure fully before use. Open the bench on level ground and check that all four feet touch at once. Sit down slowly, then apply sideways pressure. Store it folded in a dry place, raised off concrete. Inspect screws, hinges, and locking braces at the start of each season, and do not exceed about 450 pounds of evenly distributed seated weight.
Related guides
Keep reading
- A Beginner’s Plan for a Folding Picnic Tabletop That Sits on a Bench
- Summer Woodworking Plans for a Compact Folding Camp Table
- Beginner Summer Woodworking Project: Make a Folding Garden Table
- Spring Woodworking Plans for a Folding Trellis with Hinged Feet
- Build a Wooden Outdoor Game Table with a Removable Playing Surface
- Step-by-Step Plans for a Wooden Outdoor Bar Shelf with Bottle Rails