What's inside
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A trapped-cushion ottoman is a useful first furniture project: it is a simple wooden box with a padded top held in place by a recessed frame. The cushion cannot slide off, but it can still be removed for cleaning or replacement. This plan makes an ottoman about 18 inches wide, 18 inches deep, and 17 inches high, including the cushion.
Contents
Skill Level and Project Overview
Skill level: Beginner to intermediate. You need to make square cuts, drill pocket holes or pilot holes, and attach upholstery fabric. A table saw makes the build easier, but a circular saw with a straightedge works.
The frame uses 3/4-inch plywood panels, 1×2 hardwood rails, and four legs. The top rails form a shallow pocket around the cushion. Leave about 1/8 inch of clearance on each side so the cushion drops in without binding.
| Material choice | Advantages | Drawbacks | Best use |
|---|---|---|---|
| Paint-grade plywood | Stable, affordable, easy to fill and paint | Edges need filling or edge banding | Painted ottomans and utility furniture |
| Oak or maple plywood | Better-looking edges and harder surface | Costs more; veneer can splinter | Clear-finished furniture |
| Solid pine boards | Easy to find and inexpensive | Can warp, dent, or move with humidity | Budget builds with a painted finish |
Materials and Tools
Buy one 2-by-4-foot sheet of 3/4-inch plywood, four 16-inch furniture legs or turned legs, and enough 1×2 stock for the top rails and interior cleats. You will also need 1-1/4-inch pocket-hole screws or wood screws, wood glue, sandpaper, finish, and four rubber or felt floor protectors.
For the cushion, use a 17-1/2-by-17-1/2-inch piece of 3-inch medium-firm upholstery foam, a layer of quilt batting, and upholstery fabric. A 3-inch upholstery foam cushion is a practical starting point. Soft foam feels comfortable but collapses against the wooden frame; very firm foam looks crisp but may feel more like a bench than a footrest.
Useful tools include a tape measure, combination square, pencil, drill, drill bits, clamps, a sander, and a stapler. A pocket-hole jig is convenient, but ordinary screws driven through the inside of the box work just as well because the holes will be hidden.
Cut List
Cut the plywood into two side panels at 16-1/2 by 16-1/2 inches and two end panels at 18 by 16-1/2 inches. When assembled, the end panels overlap the side-panel edges, producing an outside footprint of 18 by 18 inches.
Cut four top rails from 1×2 stock: two at 18 inches and two at 16-1/2 inches. Cut four interior cleats at approximately 15 inches. Measure your actual parts before cutting the cleats; plywood thickness varies enough to affect the fit.
The 16-1/2-inch box height plus 1-1/2-inch top rails and a 3-inch cushion produces an ottoman around 21 inches tall if the legs are full length. For a lower footrest, use 10- to 12-inch legs. With 12-inch legs, the finished height is approximately 17 inches.
Build the Wooden Box
Sand the plywood faces with 120-grit paper and ease the exposed corners. Mark the inside faces so you do not accidentally reverse a panel while assembling.
Apply glue to the mating edges, clamp the panels into a square box, and drive screws from the inside. If using pocket holes, place them on the inside faces and keep them at least 3 inches from each corner. Check the diagonals before the glue sets. If both diagonal measurements are within 1/8 inch, the box is square enough for this project.
Attach the legs at the four inside corners. Position each leg flush with the bottom edge of the box and use glue plus screws driven from the inside. Do not rely on glue alone. If the legs are slightly loose in their mounting blocks, add a 3-inch square plywood block inside each corner to provide more screw-holding area.
Install the Trapped-Cushion Frame
Lay the four 1×2 rails around the top edge. The 18-inch rails run across the ends, while the 16-1/2-inch rails fit between them. Glue and screw them to the box from the inside or with carefully placed brad nails. Keep the rails flush with the outside faces.
Before fastening the rails, place the foam between them as a test. You want roughly 1/16 to 1/8 inch of clearance per side. If the opening is too tight, trim the foam with a long, sharp kitchen knife or electric carving knife. Do not force a large cushion into the opening; compressed foam can push the rails apart over time.
Install the interior cleats just below the top rails. They support the cushion base and prevent the foam from sinking into the box. Position them 1 inch below the rail tops, or lower if you want the cushion to sit deeper. A recessed cushion is less likely to slide, but a deeply recessed cushion is harder to remove.
Upholster the Cushion
Cut fabric to about 25-1/2 by 25-1/2 inches for 3-inch foam. This allows 3 inches of foam thickness plus roughly 1-1/2 inches for wrapping underneath on each side. If your fabric has a pattern, add extra material so you can center it before stapling.
Place the fabric face down, center the batting and foam on top, and fold one fabric edge over the foam. Staple the underside every 2 inches, starting at the center of each side and working toward the corners. Pull the fabric firmly, but do not stretch it so tightly that the foam develops ridges.
Fold the corners like a hospital-bed corner and trim bulky folds. A manual upholstery stapler and 3/8-inch staples are adequate for one ottoman. An electric stapler is faster, but it does not improve the finished appearance if the corners are poorly folded.
Sand and Finish
Fill visible plywood edges and screw holes, then sand through 120 and 180 grit. Round the outside corners slightly; sharp furniture corners are uncomfortable and chip easily. For paint, use primer on every plywood edge before two finish coats. For a clear finish, use a compatible polyurethane or hardwax oil and test it on scrap first.
Attach felt or rubber pads beneath the legs. Set the cushion in place and check that the rails hold it without crushing its edges. If the cushion is difficult to remove, make a small fabric loop on the underside or add a shallow finger notch to one inside rail.
Common Failure Modes
Wobbly frame: The box was assembled out of square or the legs were not the same length. Check diagonals and place the ottoman on a flat surface before the glue cures.
Cracked rails: Screws were driven too close to the ends of the 1×2 stock. Drill pilot holes and keep fasteners at least 3/4 inch from an end.
Wrinkled fabric: The fabric was pulled unevenly or the batting was bunched. Staple centers first, then alternate sides while smoothing toward the corners.
Cushion stuck in place: The opening was cut to the foam’s uncompressed size without clearance. Foam expands and fabric adds thickness, so always test the upholstered cushion—not bare foam—before final assembly.