Which Cot Mattress Should You Buy?

Cot Mattresses are made using a variety of different components. The higher the specification the longer the mattress will last, and probably the safer and more comfortable and easier to keep clean. The absolute minimum requirements for a mattress are:-

It is firm and flat, offers waterproof protection and is easy to keep clean.

Cot mattress bases

All Foam Cot Mattresses

These cot mattresses are generally made to hit a price point. They are constructed using the lowest grade of foam that will pass a British Standard test. The mattresses are in two depths 7 cm and 10 cm.

7 cm foam mattresses are really only worth buying for occasional use, for example, a few days a year at the grandparents. They will not cope with supporting a child for 12 hours a day for up to 18 months. Sometimes when you buy a cot it comes with a free mattress, this is often a 7 cm mattress.

10 cm foam mattress will last longer but the foam quality used will probably be the same rating as the 7 cm i.e. (24/130) or less.

In the UK we are conditioned to believe cot mattresses without springs are seen as inferior products, so manufacturers see no point in making cot mattresses using a high density longer lasting foam. They would be much more expensive and their value and benefits would not be appreciated.

It is very important to understand how foam is rated; it will help you choose a good quality mattress. Foam is classed using two numbers:- 24/130 the first number (24) equals the weight of foam per cubic kilo and (130) the amount of newtons it takes to compress the foam to 40% of its size. A foam rated 30 /150 would be significantly more durable than one rated 24/130.

If you see foam described as 28 CMHR it's rating will be 24/130
If you see foam described as 33 CMHR it's rating will be 30/150. This is a significantly higher grade offering more support and durability.

If you see foam described as 50 CMHR it will be 50/215. This is the highest grade you will ever find in a cot mattress and should last 7 years.It will give excellent support, comfort and durability and will last for more than one baby.

CMHR stands for is Combustion Modified High Resilient - UK fire safety standard for cot matresses

Avoid memory foam, it creates pooling, has extra chemicals, it is hot, it is not good for a baby mattress. 

Sprung Cot Mattresses

These are mattresses where the springs are encapsulated in foam. The springs are 6 cm deep the foam is 2 cm deep, (each side ) total mattress depth 10 cm.

You can now see how important the quality of 2 cm deep foam is. The foam suffers the pressure from the baby above and the springs below.

Also foam as a product does not like HEAT WEIGHT AND DAMP and that is just what a baby is!

A higher grade of foam will be more durable and cope with the everyday activity and increase the life of your mattress as well as offering more comfort and support.

Pocket Sprung Cot Mattresses

These are  pocket sprung units encapsualeted in foam. The quality of foam used to encapsulate pocket springs is critical. 

As your baby becomes heavier it puts more pressure on the foam top, The pocket springs below give more to the heavier body areas to give a more comfortable posture feel. A higher quality foam will give a more supportive comfortable sleep.


This is a relatively new component used in cot mattresses. this comes in two grades, The basic grade is a cheap component that does not have the support of foam. It will sink and dip and does not return to its former shape like foam. solid fibre mattresses are the cheapest available, a 10 cm deep fibre mattress performance will be equivalent to a 7 cm deep foam mattress.

There is a new high density fibre that can be used with pocket springs, it is more expensive and this will give the same support as 30 /150 foam and obviously a better message for the environment as the fibre is made from recycled plastic bottles.

Another advantage of fibre over foam is that it does not have any petro-chemical smell that can take 24-72 hours to  ventilate away. It is cooler and more breathable than foam. However it does not recover as well as foam unless you use a higher grade of fibre.

Coir, Lambswool

These are the main components of natural mattresses, coir is the hair on the coconut which is dried and pressed into; different matting shapes and depths. Wool is woven into large rolls so it can be easily cut to shape

Coir is available in different qualities and this does affect the firmness of the cot mattress,  A average natural mattress will have a coir block of between 6 or 8 cm deep and then 2 to 4 cm of lambswool.

The advantages of a natural mattress:-

Environmentally friendly, the coir and the lambswool will biodegrade in a few years compared to thousands of years for foam.

There is also no initial petro-chemical smell. foam may take 24- 72 hours to ventilate.

The disadvantages of coir is that it is not as comfortable as the very best pocket sprung mattresses

There is however a natural mattress available that is constructed of 200 individual coir springs, it has all the advantages of being environmentally friendly and also the comfort of a pocket sprung mattress. It is called the Nightynite® Natural Supreme, The only mattress of its kind in Europe.

Cot Mattress Covers

There are hundreds of cot mattress covers to choose from but the best cot mattress covers tick the the following boxes:-

1) Comfortable, soft, quilted.

2) Prevent any spillages getting to the foam core.

3) Easy to remove and machine washable and or wipe clean.

4) Breathable.

6) A spare cover so you have one for the wash in case of those inevitable accidents.

7) A cover that aids temperature control.

Most separate waterproof protectors are not fully breathable.

Consider putting the protector over the mattress base but under the cover. Your baby has all the advantages of sleeping on a luxury breathable mattress cover and you protect the cot mattress core. Should there be a spillage you can remove the cover for washing and if necessary wipe down thee protector. If you have a spare cover you can slip this on right away.

Some mattresses have a protective wipe clean washable base cover and on top of the base cover zips a topper. If there is an accident just unzip the soiled topper,; wipe down the protector if needed and zip on the spare topper.