Replacing the Elastic in Trousers or a Skirt – Step by Step

Replacing the elastic in trousers or a skirt starts with checking how the old one was inserted: loose in a casing or sewn to the fabric. If it is in a casing, a small opening is unpicked, the old elastic is pulled out and the new one is threaded through with a safety pin. If it is sewn in, the waistband is opened completely, the old elastic is removed and the new one is sewn in again or threaded into a newly formed casing.

When the elastic needs replacing

• the elastic has slackened and the garment slips down from the waist;
• the elastic is wrinkled or rolled inside the casing;
• you hear snapping when it is stretched – the elastic threads are breaking;
• the elastic is too tight and leaves marks;
• the garment is being repaired or altered in an atelier.

Slack elastic is the normal result of ageing, heat in the tumble dryer and frequent stretching. In many cases the garment itself is in good condition, and replacing the elastic gives it a second life.

How to tell how the elastic was inserted

Feel the top edge. If the elastic moves freely inside and the fabric slides over it, it is in a casing. If the fabric is gathered and stitched together with the elastic – with one or more rows of stitching through it – the elastic is sewn in. On factory-made joggers and leggings the elastic is often sewn in with a coverstitch; on pyjamas and light trousers it is usually in a casing.

Replacing elastic in a casing

1. Find a suitable spot. The most convenient is on the inside, at the side seam or the centre back.
2. Unpick 2–3 cm of the casing's inner seam.
3. Pull out the old elastic and cut it. Keep it – you will use it to check the width.
4. Attach the new elastic to the old one with a safety pin or a few stitches if the old one is still in the casing – by pulling the old one, you draw in the new one.
5. Thread the elastic through with a safety pin, holding the other end so it does not disappear into the casing.
6. Try the garment on before finally joining the ends.
7. Join the ends with an overlap of about 2 cm and a flat seam in a box shape or several rows of zigzag.
8. Close the opening with a straight stitch or by hand.

Replacing sewn-in elastic

1. Unpick the stitching holding the elastic. With a coverstitch, pull the bottom thread – it unravels more easily.
2. Remove the old elastic and clean away the thread remnants.
3. Decide whether the new elastic will be sewn on directly or a casing will be formed. If the fabric is deep enough, a casing is the easier repair solution.
4. For direct sewing, divide the elastic and the waist into four equal parts, mark them and sew while stretching the elastic, with a stretch stitch.
5. Fold inwards and topstitch if the style requires it.

How to choose new elastic

The width of the new elastic should be equal to or slightly less than the casing. Elastic that is too wide will not pass through and wrinkles, while elastic that is too narrow twists. If the elastic used to roll, choose a firmer woven elastic. For soft lounge and children's textiles, knitted elastic is suitable.

What length to cut

Do not copy the length of the old elastic – it has probably stretched. Measure the waist circumference where the garment will sit and cut the elastic slightly shorter – check how much to shorten it for the type of elastic with a stretch test. Add about 2 cm for the overlap. Before joining the ends, hold them with a safety pin and try the garment on.

Common mistakes when replacing elastic

• The elastic was cut to the length of the old, stretched elastic – it is loose again.
• The elastic has twisted in the casing – check it along its whole length before closing.
• The ends were joined right sides together – a hard lump forms.
• The elastic is not anchored in the casing – it twists after washing. Stitch vertically through the casing at the side seams.
• Too soft an elastic was chosen for a heavy fabric – the waist slips down again.

How to extend the life of the new elastic

• wash at the temperature on the label, avoiding very high temperatures;
• avoid tumble drying at high heat;
• do not leave the garment to dry on a radiator;
• do not iron directly over the elastic part with a hot iron.

Repairs in ateliers and garment factories

For clothing repair ateliers, replacing elastic is one of the most frequent jobs. It is convenient to keep rolls of elastic in a few basic widths in white and black, as well as soft knitted elastic for childrenswear. This way most repairs can be done straight away. All types are collected in the elastics category.

Replacing elastic in a lined skirt

In lined skirts the elastic is often in a casing formed between the shell fabric and the lining. Unpick a small section of the lining seam, not the face fabric – this way the repair stays invisible. Thread through the new elastic, check that the lining has not twisted relative to the shell fabric, and close the opening by hand with a blind stitch.

Elastics wholesale from Polkom

Polkom is a Bulgarian manufacturer and wholesaler of clothing haberdashery based in Sofia. We supply knitted, woven and round elastics in various widths and colours to ateliers, garment factories and brands across the EU. Minimum quantities depend on the article. Write to us via our contact page for samples and a quote.