How to Sew a Lap Zipper on Fabric

If you’re making a fancy dress or using special occasion fabric, or putting a zipper in the side of a skirt, sewing the zipper using a lap installation method can help hide the zipper and keep your garment looking its best. Lapped zippers use one flap of fabric to cover the zipper, rather than two small ones like a centered zipper. You may want to use a zipper that’s one to two inches longer than the opening in the garment. That way, you can leave the zipper pull above the garment and out of the way while you’re stitching, so you won’t create an uneven stitching line by sewing around it.

Difficulty: Moderate

Instructions

Things You'll Need:

• Garment
• Measuring tape
• Zipper
• Iron
• Straight pins
• Sewing machine
• Thread
• Zipper foot
• Lightweight fusible interfacing (optional)
• Seam ripper

Prepare the Zipper

1. Measure the opening in the garment from the bottom of the opening to the top of the fabric.

2. Buy a zipper as long as the garment opening, or one to two inches longer. Select a zipper that closely matches the color of the fabric.

3. Remove the zipper from the packaging if needed.

4. Remove any staples or tags in the zipper.

5. Press the zipper tape using a low-temperature iron, unless the zipper manufacturer’s directions give other instructions. This will help keep the zipper from causing the fabric to bunch up.

Pin the Lapped Zipper in Place

6. Sew the garment, including the seams around the opening, using a regular stitch length.

7. Set the sewing machine stitch length to the longest setting.

8. Baste the edges of the garment opening together using 5/8 inch seam allowance.

9. Iron the seam allowance flat.

10. If the fabric is thin or stretchy, you may want to add lightweight interfacing along the zipper opening. Cut a strip of interfacing the same width and length as the seam allowance, then fuse it to the seam allowance following the package directions.

11. Place the zipper teeth side down on the seam allowance with the bottom end of the zipper teeth just below the end of the basting.

12. Line up the left edge of the zipper tape with the edge of the left side seam allowance.

13. Pin the left side of the zipper tape to the seam allowance only. Do not put the pins all the way through the garment.

14. Attach a zipper foot to the sewing machine.

15. Sew the zipper tape to the seam allowance 1/4 inch from the edge of the zipper tape. Do not stitch through the garment.

16. Turn the zipper over to the left so that it is facing up. This causes the seam allowance to form a small fold.

17. Pin the fold in the seam allowance close to the zipper teeth without overlapping them.

Sew the Lapped Zipper to the Fabric

18. Turn the garment right side up. Carefully pin the flap to the unsewn side of the zipper, as close to the teeth as possible.

19. Topstitch the zipper to the garment using matching thread, close to the zipper teeth. Be sure to keep the fabric smooth while stitching so that it doesn’t bunch up.

20. Topstitch across the bottom end of the zipper, just above the end of the zipper teeth.

21. Carefully remove the basting stitches using a seam ripper.

22. Clip or remove any loose threads to make sure they won’t get caught in the zipper.

23. Shorten the top of the zipper if needed by opening the zipper and stitching across both sides of the zipper tape and seam allowance where you want the zipper to end. Do not stitch through to the outside of the garment. Cut off the zipper just above the stitching.

24. Finish the garment according to the pattern directions.

Tips & Warnings

• Seam allowance is the distance between the edge of the fabric and the stitches.
• Use several small pins, rather than a few large ones, to hold the zipper in place while pinning it.
• A zipper foot is a specially shaped presser foot that allows your sewing machine to stitch close to the zipper. For instructions on how to use one, see your sewing machine’s instruction booklet or the manufacturer’s website.
• Always use caution around sewing machines, irons, and pins.