How to Build a Storage Bench

A storage bench is a straightforward box with a hinged top. The build goes quickly, but the corners and the lid are where most projects fail. This guide covers joining sheet goods so the corners hold, setting the seat height, and installing a lid support that does not crush the contents.

Start with a plan. The bench top should be at a comfortable seat height, typically 18 to 20 inches (46 to 51 cm) from the floor. The depth and width depend on the space. A common size is 18 inches deep, 36 inches wide, and 18 inches tall. Adjust as needed.

Cutting the Parts

Use 3/4-inch plywood for the entire build. A single 4x8 sheet will yield the top, bottom, sides, front, and back for a bench up to 36 inches wide. Cut the parts with a circular saw and a straightedge. For clean edges, use a fine-tooth blade and cut with the good face down. Measure twice, cut once.

For a bench 36 inches wide, 18 inches deep, and 18 inches tall, the parts are:

• Top: 36 x 18 inches (91 x 46 cm)
• Bottom: 36 x 18 inches (91 x 46 cm)
• Sides: 18 x 16.5 inches (46 x 42 cm) – the height minus the thickness of the top and bottom
• Front and back: 36 x 16.5 inches (91 x 42 cm)

If the bench is against a wall, the back can be a thinner panel, but 3/4-inch is fine and adds strength.

Joining the Corners

The corners must resist racking, especially if someone sits on the bench. Pocket screws are the simplest method for sheet goods. They create a strong mechanical joint and are easy for a beginner. Use a pocket hole jig to drill holes in the sides, then glue and screw the sides to the bottom. The glue does most of the work; the screws hold the joint tight while the glue dries.

For a more traditional joint, use a rabbet and dado. Cut a rabbet along the back edge of the sides to accept the back panel, and a dado for the bottom. This is stronger but requires a router or table saw. For most builds, pocket screws are sufficient.

Assemble the box in stages. Attach the sides to the bottom first, then add the front and back. Check for square by measuring diagonals – they should be equal. Clamp the assembly and let the glue dry overnight before moving on.

Adding Cleats for the Lid

Install cleats around the inside top edge to give the lid a resting surface. Cut 1x2 lumber to fit along the sides and back, and attach them with glue and screws. The cleats also stiffen the top edge and prevent the sides from bowing inward.

Hinging the Lid

A piano hinge is the best choice for a storage bench. It distributes the load along the entire back edge, preventing the lid from sagging. Cut the hinge to length with a hacksaw, or use a continuous hinge that matches the bench width. Mount the hinge so the lid opens fully – the hinge barrel should be flush with the back edge of the bench.

Use screws that do not penetrate through the plywood. Pilot holes prevent splitting. Countersink the screws so they sit flush.

Lid Support and Safety

A lid that falls can injure fingers or damage the hinge. Use a gas spring or a folding bracket to hold the lid open. Gas springs are smooth and can support a heavy lid, but they require careful placement. A folding bracket is simpler and cheaper. Position the support so it does not interfere with stored items. Install it on one side, or use two for very wide lids.

For safety, consider a lid stay that prevents the lid from closing too quickly. Some gas springs have built-in damping. If using a folding bracket, choose one with a locking mechanism.

Finishing

Sand all surfaces with 120-grit, then 220-grit. Remove dust. Apply a primer and two coats of paint, or a clear polyurethane. For an entryway bench, a durable finish is essential. Let each coat dry completely.

Where the Build Goes Wrong

The most common mistake is making the box out of square. If the corners are not square, the lid will not fit flush, and the bench will rock. This happens when the parts are not cut accurately or the assembly is not clamped square. Check the diagonals before the glue sets. If the box is out of square, it is difficult to correct after the glue dries. Disassembly is messy and may ruin the plywood. The cost is time and materials – you may need to recut parts.

Another frequent error is placing the hinge too far forward, so the lid does not open fully. Mount the hinge as close to the back edge as possible.

Comparison of Joint Methods

Mistakes to Avoid

Skipping the cleats is a mistake. Without them, the lid rests only on the front and back edges, which can bow over time. The cleats also provide a surface for the lid support to mount.

Using a single center hinge is another error. A center hinge does not support the lid edges, causing the lid to twist. Use a piano hinge or multiple hinges spaced evenly.

Final Checks

Before finishing, test the lid. It should open smoothly and stay in place. Check that the bench does not rock on an uneven floor – shim the feet if needed. Add felt pads to the bottom to protect the floor.

A storage bench is a practical project that improves with careful assembly. Take the time to get the box square and the hinge aligned, and the bench will serve for years.