An outdoor bench cushion cover comes together with UV fabric, boxed corners, and a zipper for quick removal.
Ready to refresh a tired seat? This step-by-step guide shows a clean, durable method that holds up through sun and showers. You’ll measure once, cut with confidence, sew straight seams, and end with a snug, washable slip that looks store-bought—sharp.
The method suits straight benches and standard outdoor pads at any length nicely.
Making A Garden Bench Cushion Slipcover – Tools And Prep
Good prep saves time and fabric. Gather sturdy materials that tolerate weather, mark your measurements, and set up a safe, comfortable workspace before you touch the shears.
| Item | Why You Need It | Notes |
|---|---|---|
| Solution-dyed acrylic or olefin fabric | Colorfast and UV stable for outdoor use | Look for 54–60″ width; pick a tight weave |
| Outdoor foam or existing pad | Holds shape and resists water | Reticulated “dry fast” foam drains quickly |
| UV-resistant polyester or PTFE thread | Strong seams in sun and rain | Use Tex 70–90 with a size 16–18 needle |
| Nylon coil zipper | Easy on curves; corrosion resistant | Length equals cushion width; #5 or #7 slider |
| Seam ripper, clips, chalk | Clean layout and corrections | Clips beat pins on thick fabric |
| Walking-foot machine (or even feed foot) | Feeds layers evenly | Lengthen stitch to 3–3.5 mm |
| Spray adhesive (foam to batting, optional) | Smooths lumps | Light mist only; let it flash off |
| Polyester batting (optional) | Softer edges under fabric | Wrap once around foam |
Measure The Bench And The Pad
Write down three numbers: length, depth, and thickness. If you’re replacing only the cover, measure the existing pad. If you’re making a new pad, size the foam to match the bench platform with a small gap—about 0.25″—so the cushion slides in and out without rubbing the arms.
Tight seats look sharp. If your foam is springy, subtract 0.5″ from the length and depth when you cut panels. That light compression removes wrinkles and keeps corners crisp.
Plan The Panels And Seams
Most bench cushions use a “box” build: a top, a bottom, and long strips around the sides. A zipper across the back edge gives easy access for washing. Keep the grain straight and mirror any prints so the pattern reads level across the front.
Cut List Formulas
Use these formulas to draft your cut list. All sizes include a 0.5″ seam allowance.
- Top: length × depth
- Bottom: length × depth
- Front boxing: length × thickness
- Back boxing with zipper: length × thickness
- Side boxing (2): depth × thickness
Add 2″ to each boxing length so you can square edges and trim clean after assembly. Stripe or check prints may need extra to match repeats; buy one extra repeat to be safe.
Cut Fabric With Straight Grain
Lay the cloth right side down on a large surface. Align the selvage edges, square the first cut, and mark with chalk and a rigid ruler. Use a rotary cutter on a mat for the cleanest edge, or shears if that’s your setup. Label each piece: top, bottom, front, back, and sides.
Sew The Zipper Panel
Place the zipper face down on the right side of the back boxing. The zipper tape edge aligns with the raw fabric edge. Stitch with a zipper foot, then flip the tape out and topstitch 0.25″ from the seam to keep fabric off the teeth. Repeat for the other side of the tape so the zipper sits centered in the back strip.
Bar-tack at both ends to stop stress. Test the slider; it should move freely without waves. If the panel tunnels, press from the wrong side with a warm iron and a press cloth.
Join Boxing Strips Into A Loop
With right sides together, sew the front strip to one side strip. Sew the other side strip to the zipper strip. Join the ends to complete a loop. Press seams open. Mark the midpoint of each edge with a small notch; do the same on the top and bottom panels. These marks help align corners.
Attach Boxing To The Top
Pin or clip the boxing loop to the top panel, right sides together, matching midpoints and corners. Sew with the top panel down so you can steer the exact seam line along the curves. Stop 0.5″ before each corner, pivot with the needle down, and continue along the next side. Keep a steady 0.5″ allowance.
Close The Shell With The Bottom Panel
Repeat the alignment process with the bottom panel. Open the zipper halfway so you can turn the cover later. After stitching, trim bulk at the corners by snipping diagonally through the allowance—just short of the seam. Turn right-side out through the zipper and push out points with a blunt tool.
Tips That Make Outdoor Covers Last
Long life comes from material choices and neat construction. Pick UV-stable cloth, weather-tough thread, and hardware that won’t corrode. Keep stitch length a bit longer than indoor sewing to avoid perforating the fabric. Backstitch at starts and ends, and add a second line of topstitching on stress zones like zipper ends.
Cleaning stays easy when the cover opens wide. A full-length zip keeps foam out of the splash zone during wash day and lets the shell dry fast on a line.
Slip The Foam In And Shape The Corners
Wrap the foam with a light layer of polyester batting for softer edges, then compress the pad slightly and feed it through the open zipper. Work the corners fully into the cover. Zip the back, then karate-chop the front edge to set the boxing line. Smooth the top with your palm for a tailored finish.
Care And Weather Smarts
Shake off leaves and dust during the week and brush seams before they settle. Spot clean with mild soap and water, rinse, and air-dry flat. For tough stains on solution-dyed acrylic, bleach-safe methods keep colors steady; follow the fabric maker’s guidance for ratios and dwell time. Store the cushion indoors during long storms to extend life.
Close-Match Keyword Variant: Garden Bench Cushion Cover Tutorial Steps
This section walks through the entire build in a single pass so you can sew without jumping around the page.
Step 1: Measure
Record length, depth, and thickness to the nearest 1/8″. Check the bench for a taper; if the back runs shorter than the front, note both depths and split the difference or draft a slight wedge.
Step 2: Draft The Cut List
Use the formulas above. Add 2″ to the total fabric length for squaring and 10% more yardage for pattern matching. Most outdoor fabric comes 54″ wide; plan your nesting on paper and you’ll avoid a second trip to the store.
Step 3: Cut
Square the first edge, then cut panels with the grain. Keep labeling as you go. Save long offcuts for strap ties or a narrow bolster.
Step 4: Zipper Panel
Center the zipper in the back boxing strip. Stitch, flip, and topstitch. Check that the slider parks near a side seam so it hides from view when installed on the bench.
Step 5: Boxing Loop
Join strips, press, and notch midpoints. Keep seams offset so they don’t stack at one corner. If your bench has rounded front corners, trace a 1.5″ radius on the top panel and follow that line during assembly.
Step 6: Sew To Top And Bottom
Attach the loop to the top, then the bottom. Open the zip before the final pass. Trim corners and turn right-side out.
Step 7: Fill And Finish
Wrap, insert, shape, zip, and set the boxing line with a firm chop. If you see ripples, steam lightly from a distance and smooth by hand.
Cutting Math At A Glance
| Piece | Size Formula | Sample (48″ × 18″ × 3″) |
|---|---|---|
| Top | length × depth | 48″ × 18″ |
| Bottom | length × depth | 48″ × 18″ |
| Front boxing | length × thickness | 48″ × 3″ |
| Back boxing (zip) | length × thickness | 48″ × 3″ |
| Side boxing (2) | depth × thickness | 18″ × 3″ |
Fabric, Thread, And Foam Picks
Cloth: solution-dyed acrylic or olefin gives fade resistance and easy cleaning. Thread: bonded polyester handles most outdoor seats; PTFE thread resists sun for years and trades a higher price for close to zero stretch. Foam: reticulated “dry fast” foam sheds water and dries fast, which reduces musty smells between storms.
Small Upgrades That Matter
- Piping: Cut bias strips from the same cloth or a contrast stripe and sew with cording for a crisp outline.
- Corner guards: Fuse small patches of lightweight cloth to the inside at all four corners before turning.
- Hidden handle: Add a webbing loop at the back seam to lift the pad with one hand.
- Non-slip: Sew two bands of silicone shelf liner to the underside to stop sliding on wood slats.
Troubleshooting
Wavy Zipper
Lower presser foot pressure, lengthen the stitch slightly, and topstitch both sides evenly. A walking foot keeps layers moving together.
Rounded Corners Look Baggy
Reduce the radius or add light batting only on the top face so the profile fills out. Set the foam fully into the corner before judging the fit.
Seams Pucker
Re-thread, check needle size, and keep tension balanced. Heavy cloth likes a fresh size 16–18 needle and a 3–3.5 mm stitch length.
Care Reference Links
For cleaning methods that protect color on solution-dyed acrylic, see the fabric maker’s care guide. For a deeper look at outdoor foam types and why reticulated cores dry fast, read this foam guide.