How to sew a lapped zip

A lapped zip is hidden under a flap of fabric on one side. It's common on skirts and trousers and is a good next step after a centred zip.

Pinny's tip
Baste the seam closed where the zip goes, press it open, then sew the zip in. Unpick the basting last.

What you'll need

• Standard zip: a little longer than the opening.
• Zip foot: to sew close to the teeth.
• Basting thread: contrast colour so it's easy to remove.

Step by step

1. Sew the seam below the zip at normal stitch length and backstitch. Baste the zip opening closed with the longest stitch.
2. Press the seam open. Extend the right-hand seam allowance (as worn) about 3mm (1/8 in) beyond the seam to form a narrow fold.
3. Place the zip under that fold with the teeth close to it and sew the fold to the zip tape with a zip foot.
4. Close the zip and lay the garment flat, right side up. The left side now covers the zip.
5. Topstitch about 0.4 in (1 cm) from the seam down the left side and across the bottom, catching the other zip tape.
6. Remove the basting and press.

Common mistakes

• Skipping the basting. The lap won’t sit evenly.
• Topstitching too close. The teeth show; stay about 0.4 in (1 cm) away.
• Sewing over the pull. Stop, needle down, lift the foot and slide the pull past.

Watch it done

• Learn to Sew – How to Insert a Lapped Zip on YouTube. Opens on YouTube; the video belongs to its creator.
• Inserting a Lapped Zipper for Beginners | Sewing Tutorial with Callie Works-Leary by Craftsy on YouTube. Opens on YouTube; the video belongs to its creator.
• How to Sew a Lapped zip (Two ways) by The Sewing Whisperer on YouTube. Opens on YouTube; the video belongs to its creator.

Sources

All checked November 1, 2026. We read these; we did not test the products ourselves.

1. YouTube: Inserting a Lapped Zipper for Beginners | Sewing Tutorial with Callie Works-Leary (Craftsy)
2. YouTube: How to Sew a Lapped zip (Two ways) (The Sewing Whisperer)