A bench with a hinged top is an asset around the home and garden. When constructed of durable materials, it becomes an all-season, all-purpose tool for the avid gardener or handy do-it-yourself homeowner. Favourite tools and equipment can be stored inside, and, if not too heavy, the bench can easily be moved to and from any desired spot in the home or garden.
Use the measuring tape and carpenter's pencil to measure and pencil mark outlines of the bench pieces on a full 1-inch plywood sheet. Mark the front and back pieces for 12 inches by 48 inches and the side pieces for 12 inches by 12 inches. Mark the bottom for 10 inches by 44 inches and the top for 16 inches wide by 48 inches long. This will allow the top to overhang the bench box below so that the foam padding, fabric cover and hinge can be fastened to the bottom inside edge of the top. Measure twice, and then check the measurement again. Use a level surface area for all measuring, cutting and assembly of pieces.
Use the pencil and metal square to measure and mark the base material for cutting. Use the 2 by 8 pieces for the base boards; the front and back pieces should be 46 inches long, and the end pieces should be 12 inches long. Measure and mark a centre cross piece; this will be between the front and back base pieces and should be 9 1/2 inches long. Measure twice, and then check the measurement again.
Cut all the wood at the same time. Make sure the power saw is sharp and that you use blue painter's tape to cover the cut lines before sawing to avoid excessive splintering of the wood at the cut edges. Cut and set the pieces aside in groups to easily find.
Mitre cut all plywood edges that fit together. Mitre cut at a 45-degree angle. Cut the front and top pieces where they meet with the end pieces. Cut mitres at each end piece where it meets with the front and back mitre cut pieces. Be sure the mitre saw is set perfectly at 45 degrees for a true mitre cut and that the plywood front, back and end boards fit after cutting, with no gaps where the boards meet at the 45-degree angle.
Mitre cut all base piece edges that fit together. Mitre cut at a 45-degree angle. Cut the front and top pieces where they meet with the end pieces. Cut mitres at each end piece where it meets with the front and back mitre cut pieces. Be sure the mitre saw is set perfectly at 45 degrees for a true mitre cut and that the 2 by 8, front, back and end boards fit after cutting. Option: Use hand saw to cut centre cross piece.
Do not mitre cut the cross 2 by 8 piece, as it will fit between the front and back base boards exactly at the centre of the inside base dimension and requires only the original right angle cut used to establish the length of the piece.
Assemble the base pieces by nailing or screwing the 2 by 8s together at the mitre corners. Drill starter holes to eliminate splitting. Use a drill bit slightly smaller than the screw or nail diameter. Place a bead of wood glue prior to fastening together. Place the centre cross piece so it fits flush with the front and back base pieces, and fasten it with the wood glue. Set the base aside until the glue dries.
Assemble the front, back and end pieces by nailing or screwing the 1-inch plywood pieces together at the mitre corners. Drill starter holes to eliminate splitting. Use a drill bit slightly smaller than the screw or nail diameter. Place a bead of wood glue prior to fastening together. Set the assembled bench box aside until the glue dries.
Fasten the bottom plywood piece to the base assembly. Glue and screw so that it fits flush with the outside edges of the base pieces. Let the glue dry.
Lift up and set the bench box assembly onto the base with the bottom attached. The bench box assembly should fit so that the plywood overlaps the 2 by 8 base pieces for the front, back and ends. Use the box level to help keep the bench assembly level by checking that exactly 6 inches of the 2 by 8 wood base assembly is exposed to view below the plywood bottom edge. Use scrap material cut to exactly 6 inches as lifting blocks to help hold the box in place in a level position while screwing the plywood onto the base. Rest the bench box assembly plywood on these lifting blocks, then secure the plywood to the 2 by 8 base assembly. There will be a 1 1/4 inch dimension from the bottom of the plywood to the top of the 2 by 8 base piece in which to screw the plywood to the base. Use 2-inch brass screws at about 3 inches on centre to fasten the plywood bench box to the wood base. Do not use glue in this instance, just screws. When finished, check the bench level with the box level, and adjust if necessary. After complete assembly, check all exposed edges and fill any open gaps or splinter openings with wood filler. Let dry and sand smooth. Stain or paint entire bench inside and outside exposed surfaces. Allow area for hinge to be connected to raw wood.
Attach the piano hinge to the bottom edge of the plywood top piece so that it will be secured to the outside of the back plywood piece, allowing the top to close on the bench freely. The top will have a 2-inch overhang, allowing sufficient room to install the hinge and to use the edge as a fastening point for the foam and fabric cover for the top. The lip on the top will allow easy opening. If desired, install a top retainer at each end of the top that is connected to the inside end pieces. The retainer can be the wire type or slotted type. If you want to save money, use a chain or small rope on each end as a top retainer. Screw the rope or chain to the top and ends. The retainer ensures that the bench seat top will not open beyond a 90-degree position when raised, which would strain the hinge.
Sketch the bench design on graph paper; include a sketch of plywood sheet showing each piece to be cut out from the plywood. Allow for the width of the saw blade when sketching and cutting. Place a single bead of wood glue at all fastened joints. Use levelling blocks to temporarily hold plywood while securing to base assembly.
Wear protective goggles when sawing. Be careful when using power tools.