Why Does My Laundry Shrink In The Wash?

If you have ever used a washing machine, it’s likely you have shrunk some of your clothes. Usually it’ll be your favourite t-shirt or one of your best sweaters.

The thing is, you’re not on your own, shrinking clothes in the washing machine and/or tumble dryer is all too common. There can’t be many people that have not pulled shrunken clothes out of the machine after they’ve been washed.

Why Do Clothes Shrink?

The reason clothes shrink in the wash is because they have been washed incorrectly. Different materials react in different ways when subjected to heat, liquid and agitation.

The average shrinkage that is considered to be normal is anywhere between 2 to 3% for items that have not been prewashed.

There are several reasons why fabrics shrink with many happening during the manufacturing stages when synthetic or natural fibres are made into clothing materials.

Once the clothes have been made and sold there are 4 processes that cause clothes to shrink, which are;

1. Felting
   Felting is found mostly in clothes made from animal hair like wool or cashmere. The fibres of these hairs have miniscule scales along their surface which collapse and web together when subjected to heat and moisture which causes the fibres to shorten. This is the most common cause of wool sweater shrinkage.
2. Relaxation
   Relaxation shrinkage is what happens to organic materials like cotton or hessian. When the yarns or threads that make the material are stretched during the weaving process. Which makes the fibres longer and when washed in warm water, the fibres return to their original shape and size. This is less likely to occur in pre washed clothes as the bulk of the shrinkage happens during the garments first wash.
3. Consolidation
   This tends to happen during the washing and drying process and is a result of the fibres becoming softened and compressed due to the bashing together of the clothes in the drum of the machine.
4. Contraction
   Contraction is caused by the materials having all of their moisture content removed. The moisture content of cotton for example is around 5% and wool has a moisture content of around 17%. The drying action of the tumble dryer removes too much moisture which causes the fabrics to shrink. This is often the reason for wool and cotton clothes to shrink. Not so much synthetic fibres as they have a very minute moisture content.

Certain materials are often more prone to one type of shrinkage. However, it is often 2 or more of these that cause your clothes to shrink.

Different Fabrics Shrink In Different Ways

Natural fibres typically shrink more than synthetic fibres especially if exposed to high temperatures. However, synthetic fabrics can also shrink at high levels of heat but it’s more common for natural fibres to shrink.

Wool, Mohair & Cashmere Clothing

Fabrics made from animal hair have a scale-like structure which is likely to be susceptible to felting. But these fabrics are also likely to suffer from the other 3 types of shrinkage too. Which makes wool especially likely to shrink in the washing machine.

Cotton Clothes

Cotton fabrics are likely to suffer from shrinkage due to relaxation. The fibres which were stretched during manufacture become relaxed in warm water. Loosely woven cotton fabrics can also suffer from consolidation and if cotton clothes are tumble dried they can shrink due to contraction if they are over dried.

Silk Clothes

Silk is likely to shrink due to contraction if it is exposed to heat and water for long periods. If the silk has been loosely woven, the garment can have a shrinkage rate of as much as 15% if washed in hot water and dried on high heat in a tumble dryer.

Linen Clothes

Linen garments, made from flax fibre can shrink due to relaxation and contraction if they’re washed and tumble dried at high temperatures.

Synthetic Fabrics

Clothes made from polyester, nylon or one of the other man made fibres produced from the waste products of the petroleum industry, tend to not shrink as they don’t undergo any rigorous stretching during manufacture. However, if they’re exposed to intense heat either in the tumble dryer or through ironing or even steaming, they can shrink.

Clothes Made From Knitted Fabrics

Any type of fabric that is knitted as opposed to woven will be more likely to shrink. This is due to the fabrics having more space between the strands of yarn. This allows more consolidation to occur as the garments are washed over and again.

Ways To Prevent Clothes From Shrinking In The Wash

There are several ways you can help to prevent clothes from shrinking in the wash. They include;

• Always Follow The Advice From The Care Label
  Clothes manufacturers add care labels to help you keep your clothes looking good for longer. Always follow the advice on the care label for your clothes. 
• Wash Clothes In Cold water Whenever Possible
  Unless your clothes are extremely dirty or need to be disinfected, use a cold or 30 degree wash cycle. You will find clothes are more likely to shrink in hot water.
• Always Use Wash Cycles Designed For Specific Fabrics When Possible
  Check your washing machine’s user manual, you could find specific programs for items such as silk, wool, cotton etc. If you’re not sure which setting to select, choose a delicate wash.
• Always Select A Low Heat Drying Cycle
  If you’re drying your clothes in a tumble dryer, always select the lowest heat setting possible and always remove the clothes from the dryer as soon as the cycle ends. If you’re not sure which setting is the lowest heat, choose the delicates setting.

You could always buy preshrunk clothes that will usually maintain their shape even after washing. Or you could try wearing mainly synthetic or blended clothes.

Synthetic clothes are less likely to shrink due to the material used to make them and the way they are made. Blended clothes are usually a mixture of cotton and synthetic materials which are also more likely to maintain their shape.

Plus, blended clothes are often more comfortable than fully synthetic clothes.

Is It Possible To Restretch Clothes That Have Shrunk?

In most cases, once the garment has shrunk, it cannot be restretched back to its original size. However, some woollen or cotton garments can sometimes be returned to their original size by mixing ¼ of a cup of baby shampoo or hair conditioner in a bucket of lukewarm water and soaking the garment for 15 to 30 minutes.

Then roll the garment in a towel to remove excess water and then gently stretch the cloth in sections from side to side and then from top to bottom.

Keep repeating this process until the garment gets back to its original size. Then leave it to dry naturally. This doesn’t always work, but what do you have to lose? You can’t wear the clothes in their shrunken state anyway.

Frequently Asked Questions