Fix a Split Seam

What you will learn

• Unpicking safely
• Matching an old stitch line
• Backstitching

Materials and tools

• All-purpose polyester thread matching the garment
• Hand-sewing needle (sharps, size 8) or machine needle 70/10 for light fabric, 80/12 for medium, 90/14 for heavy
• Pins or clips
• Seam ripper
• Small scissors
• Iron and press cloth

Before you start

• Assess the damage. Turn the garment inside out and look at both seam edges. If the fabric is whole and not frayed down to the stitch line, this repair works.
• If a strip of fabric has torn away or the allowance is frayed to nothing, use rep-tear-near-seam instead.
• Find the cause. A seam splits when the garment is a bit tight, when the thread is weaker than the fabric, or when the stitches were too long. If the garment is too small, the new stitching will split again.
• Look at the old stitches. Count the stitches per inch and copy that length. Most woven garments have about 10 to 12 stitches per inch (a stitch length of 2.5 mm).
• Choose the method. Machine is quicker and stronger over 3 in (8 cm). Hand backstitch is better under 3 in or inside a lined garment.

1. Turn the garment inside out. Use the seam ripper to remove 1/2 in (12 mm) of loose stitching past each end of the split, so you start and finish on a firm seam.
2. Brush out loose thread ends. Press the seam flat with an iron at the temperature on the care label, using a cloth on delicate fabrics.
3. Pin the two layers right sides together with the edges level. Match the fold lines, notches or old needle holes. The seam allowance, the strip of fabric between the stitching and the raw edge, is usually 5/8 in (15 mm) on dressmaking and 3/8 in (10 mm) on shirts.

4. For machine: start 1/2 in (12 mm) inside the sound stitching, backstitch (reverse) 3 stitches, then sew along the old stitch line slowly. Finish 1/2 in past the split and backstitch again.
5. For hand: use a knotted doubled thread. Backstitch along the old holes with stitches about 1/8 in (3 mm) long, overlapping the good seam by 1/2 in (12 mm) at each end.

6. Reinforce high-stress areas. Sew a second row 1/8 in (3 mm) beside the first, inside the seam allowance, or backstitch twice over the hand repair.
7. Trim the thread tails. If the edges fray, zigzag or oversew the raw edges together. Press the seam open or to one side as before.

Tips for a neat result

• Match the thread colour to the stitching you see from the right side, not to the reel.
• Test the repaired seam by pulling it gently apart with both hands before you wear the garment.
• Use polyester thread, which is stronger than cotton for a seam that carries tension.

Common mistakes and fixes

Check your result

• The seam lies flat with no puckers.
• The thread colour is hard to see from the outside.
• Both ends of the repair overlap the old stitching.

Projects that use this