Drag an orange dot to resize; a dashed line shows when it snaps to a common size. Click a dot, then use the arrow keys to nudge 1/8″ (hold Shift for 1″). Every size can also be typed in the panel.
Checks
- The top passes the sag check.
- The middle brace passes the sag check.
Shopping list
| Qty | Item | Est. |
|---|---|---|
| 1 | 4×4 post, 8′ (board) | $11.20 |
| 1 | 1×2 pine board, 6′ (board) | $4.20 |
| 1 | 2×4 stud, 8′ (board) | $4.80 |
| 1 | 3/4″ birch plywood, 4×8 sheet (sheet) | $68.00 |
| 1 | 1 5/8″ wood screws (box of 100) | $9.00 |
| 1 | 1 1/4″ wood screws (box of 100) | $7.00 |
| 1 | Wood glue (bottle) | $5.00 |
| 3 | 3″ high-density upholstery foam (order cut to size or by the sheet) (sq ft) | $18.00 |
| 2 | Polyester upholstery batting, 1/2″ loft, 45″ wide (yard) | $14.00 |
| 2 | Upholstery fabric, 54″ wide (heavy-duty, rated for seating) (yard) | $50.00 |
| 1 | Black cambric dust-cover cloth, 36″ wide (yard) | $5.00 |
| 1 | 3/8″ staples to fit your staple gun (box of 1250) | $6.00 |
| 1 | Foam spray adhesive (can) | $14.00 |
| 1 | Felt floor pads (pack) | $5.00 |
About $221 · rough estimates, check the store
Parts
| Part | Qty | Length | Width | Material | |
|---|---|---|---|---|---|
| A | Top board Round the top edges before padding. | 1 | 18″ | 18″ | 3/4″ birch plywood |
| B | Front and back panel | 2 | 18″ | 10 1/16″ | 3/4″ birch plywood |
| C | End panel | 2 | 16 5/8″ | 10 1/16″ | 3/4″ birch plywood |
| D | Leg Sand the bottom edges round so they don't splinter when the piece is dragged. | 4 | 14 1/16″ | 3 1/2″ | 4×4 post |
| E | Top cleat, long | 2 | 9 5/8″ | 1 1/2″ | 1×2 pine board |
| F | Top cleat, short | 2 | 9 5/8″ | 1 1/2″ | 1×2 pine board |
| G | Middle brace | 1 | 16 5/8″ | 3 1/2″ | 2×4 stud |
Cut list
3/4″ birch plywood, sheet 1 of 1
4×4 post, 96″ → D 14 1/16″ · D 14 1/16″ · D 14 1/16″ · D 14 1/16″
1×2 pine board, 72″ → E 9 5/8″ · E 9 5/8″ · F 9 5/8″ · F 9 5/8″
2×4 stud, 96″ → G 16 5/8″
Kerf 1/8″ included. Every cut runs edge to edge.
Have the store cut it
Most home centers rip sheets on their panel saw. Show them this; do the short crosscuts at home.
- 3/4″ birch plywood: rip into strips 18″, keep the rest.
Steps
- Tape measure
- Speed square
- Pencil
- Drill/driver
- Clamps
- Safety glasses
- Hearing protection
- Dust mask
- Circular saw and a straight edge (or have the store cut the sheets)
- Miter saw, or circular saw in two passes, for 4×4 posts
- Countersink bit
- Staple gun with 3/8″ staples (electric is easier on the hand)
- Electric carving knife or a long serrated bread knife (for foam)
- Sharp fabric scissors
- Flat screwdriver and needle-nose pliers (to pull bad staples)
- Marker and a long straightedge
- Fabric glue (optional, for the side seam)
- Sander, 120 and 180 grit
1Before you start
Read every step once, start to finish, before you buy or cut anything. Each step names the parts it uses by letter; the parts list gives their sizes.
Set up somewhere flat with good light. A pair of sawhorses with a sheet of plywood on top makes a fine work table.
Wear safety glasses whenever a tool is running, hearing protection for saws, and a dust mask for sanding and for cutting treated wood or sheet goods. Tie back long hair and loose sleeves. Keep children and pets out of the work area.
- Tip At the store, pick straight boards: hold each one up to your eye and look down its length. Skip boards that bow, twist or have big knots near the ends.
- Tip Measure twice, cut once. Most mistakes are a misread tape, not a bad cut.
2Cut and label the parts
Cut every part on the cut list. Cut the longest parts first: if one goes wrong, it can still become a shorter part.
To mark a cut, hook your tape on the end of the board, make a small V with its point exactly at the measurement, and draw a square line through the point with a speed square. Put an X on the waste side.
Cut on the waste side of the line, so the blade's kerf (about 1/8″) comes out of the scrap, not your part. Cut sheets with the good face down when using a circular saw: the blade splinters the top face.
Write each part's letter in pencil on a face that won't show, and stack the parts by letter.
Sand the faces before assembly while they're flat and easy to reach: 120 grit, then 180.
✓ Lay the parts out and count them against the parts list. Measure a few: if one is off by more than 1/16″, recut it now.
STOP. Let the saw reach full speed before it touches the wood, keep both hands clear of the blade's path, and never reach under a board you're cutting. Support long boards on both sides of the cut so the blade doesn't pinch.3Build the box around the legs
Lay a front or back panel (B) good face down. Set two legs (D) on it, one in each corner: each leg is 11/16″ in from the panel end (where the end panel will fit) and its top is flush with the panel's top edge. The legs stick out 4″ past the bottom edge: those are the feet.
Glue each leg where it touches the panel, then drive 4 screws, 1 5/8″, through the panel into each leg in a square pattern 1″ in from the leg's edges. Drill pilot holes and countersink so the heads sit flush.
Do the same with the other long panel and the other two legs. You now have two halves.
Stand the halves up facing each other and fit the end panels (C) between the long panels, against the legs. Glue and screw each end panel to its two legs the same way, and drive 3 more screws through each long panel into the end panel's edge (pilot holes are a must here: plywood edges split).
- Tip Clamp the leg to the panel before screwing so it can't slide.
- Tip Mark the screw positions with a combination square so the rows look neat if the box is painted.
- Tip If it rocks, slip a shim under the short leg, mark the others and sand them down a little.
✓ Measure the box corner to corner across the top both ways; the diagonals match within 1/8″. The box is 18″ × 18″ and sits flat with no rocking.
4Add the top cleats and the middle brace
Glue a top cleat (E on the long sides, F on the ends) flat inside each panel between the legs, its top flush with the box top. Drive 1 1/4″ screws through the panel from the outside into the cleat every 6″.
Fit the middle brace (G) on edge across the middle of the box, from the front panel to the back, top flush. Glue the ends and drive 3 screws, 1 5/8″, through each panel into the brace ends.
The cleats give the top board something to screw into, and the brace halves the distance the top spans so it doesn't bounce when someone sits in the middle.
✓ Lay a straightedge across the box top: the cleats, brace, leg tops and panel edges are all flush.
5Cover the box sides
Cut a strip of batting 10 1/16″ tall and long enough to go all round the box (72″). Spray the box sides lightly with adhesive and wrap the batting on, edges flush with the top and bottom of the panels, ends butted (not overlapped) at a back corner.
Cut a strip of fabric 14 1/16″ tall and 76″ long (join two pieces with a seam on the sewing machine, or start a second piece at a back corner, if your fabric is too short). Wrap it round with 2″ extra at the top and bottom.
Starting at a back corner, fold the fabric's raw end under by 1″ and staple it down the corner. Pull the strip snug around the box, then fold the top 2″ over the top edge and staple it onto the tops of the cleats every 2″ (the top board will cover these staples). At the bottom, wrap the fabric under the bottom edge onto the inside face of the panels and staple it there.
Finish at the starting corner: fold the raw end under so the fold sits exactly on the corner, and fix it with a line of fabric glue or a few staples hidden in the fold.
- Tip Cut the fabric in the legs' corners with a small slit so it wraps neatly around them inside the box.
- Tip Hold the fabric tight with a few clamps along the top while you staple the bottom.
✓ The fabric is tight with no ripples and the pattern runs straight round all four sides.
6Glue the foam to the top board
Round over the top edges of the top board (A) with 120-grit sandpaper so they can't cut through the fabric over time.
Lay the top board on the 3″ foam and trace around it with a marker. Draw the line 1/4″ outside the board all round: foam cut slightly big fills the fabric and keeps the edges plump.
Cut the foam with an electric carving knife (or a long bread knife), holding the blade straight up and down and using long, smooth strokes. Don't press down; let the blade do the work.
Outdoors or with a window open, spray a light coat of spray adhesive on the top of the top board and on the bottom of the foam. Wait about a minute until it feels tacky, then set the foam on, edges lined up, and press it down with flat hands from the middle out.
- Tip Cut foam on a scrap board or cardboard so the knife doesn't mark your table.
- Tip If the cut edge is wavy, trim it again with the knife held flat against a straightedge.
✓ The foam overhangs the board by about 1/4″ on every side and does not peel up at the corners.
7Wrap the batting
Cut a piece of batting 28″ × 28″ for each top board.
Lay the batting flat and set the top board on it foam-side down, centred.
Pull the batting up over the front edge onto the underside of the board and put one staple in the middle, 1″ in from the edge. Do the same at the back, then each side. Then add staples every 3″ working from the middle toward the corners.
At each corner, cut away the extra batting in a V so the corner is not lumpy. Batting should just meet itself, not pile up.
- Tip Batting tears if you pull hard. Pull just enough to take out the slack.
✓ Run your hand over the top and edges: smooth, no lumps or folds, and the foam edges look rounded.
8Staple the fabric
Iron the fabric if it has creases. Cut a piece 30″ × 30″ for each top board, with any pattern or stripe running from front to back and centred.
Lay the fabric face down on a clean table and set the padded top board on it foam-side down, centred. Check the pattern is straight before stapling.
Staple in this order so the fabric pulls evenly: one staple in the middle of the front edge on the underside, 3/4″ in from the board edge. Pull the fabric firm (snug enough to smooth wrinkles, not so tight it dents the foam) and put one staple in the middle of the back. Then one in the middle of each side.
Now work from those middle staples out toward the corners, alternating sides: a staple every 1 1/2″, pulling each bit of fabric the same amount. Stop 2″ short of each corner.
Flip it over often to look. A wrinkle on top means that part is pulled less than its neighbours: pry the staples there out with a flat screwdriver, pull a little more and re-staple.
- Tip Press the staple gun nose hard against the board before squeezing. A staple that stands up can be tapped flat with a hammer or pulled with pliers.
- Tip Stripes and plaids show every crooked pull; a plain or small-pattern fabric is easier for a first seat.
✓ From the top, the fabric is smooth, the pattern is straight front to back, and the sides look even.
STOP. Keep your free hand behind the stapler nose, never in front of it. Unplug an electric staple gun before clearing a jam.9Fold the corners and add the dust cover
At one corner, pull the point of the fabric straight across the corner onto the underside and staple it once. This anchors the corner.
Take the fabric on one side of the corner, fold it under itself so the fold line runs exactly down the corner edge, and pull it onto the underside. Staple it. Do the same with the other side. You now have a neat pleat on each side of the corner, like the end of a wrapped present.
Trim off the bulky fabric left on the underside at the corner with scissors, leaving 1/2″ past the staples.
Do the other corners the same way so all four match. Then cut the dust-cover cloth 1/2″ smaller than the top board all round, fold its edges under 1/2″, and staple it over the underside every 2″ to hide the raw edges.
- Tip Practise one corner on a scrap of fabric and a block of wood first: it takes most people two tries.
- Tip Keep the pleats on the sides of the seat, not the front, so they are out of sight.
✓ All four corners look alike, with no puckers on top. The underside has no loose fabric hanging down.
10Screw the top on
Turn the padded top (A) upside down on a clean blanket and set the box upside down on it, edges lined up all round.
From inside the box, drive 1 1/4″ screws up through every cleat into the top board, 4 per cleat, and two through the brace.
- Tip 1 1/4″ screws are the longest that fit here; anything longer comes through into the foam.
✓ Turn it over. The top sits square on the box, nothing pokes through, and it doesn't shift when you push it.
11Test it
Before anyone uses the ottoman, sit down slowly, then rock gently side to side and front to back. Nothing should creak, shift or rack. If a joint moves, add glue and a screw there before going further.
Put felt pads under the legs so it slides without scratching the floor.
✓ Nothing creaks and the top doesn't dip at the middle.
12Finish
Ease every sharp edge and corner with 120-grit sandpaper so nobody gets a splinter.
Sand all over with 180 grit, always along the grain (the direction the wood fibres run). Scratches across the grain show through stain.
Wipe off the dust with a barely damp rag and let it dry.
Paint, stain or a clear coat (water-based polyurethane is the easiest). Apply thin coats with the grain, let each dry fully, and sand lightly with 220 grit between coats.
Let it dry for the time on the can before using it.
- Tip Try your finish on a scrap of the same wood first: stain looks different on every board.
Conceptual layout, material estimate and assembly guide from the sizes you entered. Not engineering, not a building plan, not stamped or approved. Confirm measurements on site; follow local codes and product instructions; anchor tall pieces before use. Using this plan means you accept the Terms of Use.