Mattress Settlement and Body Impressions.

Mattresses are primarily based on

a support unit which is then topped with comfort layers.

It is when these comfort layers start to compress that beds suffer from dips and sags; known as mattress settlement.

In a quality mattress, these will be natural fibres whereas in cheaper entry-level models this may be polyester or foam. Either way, these comfort fibres will start to settle once you’ve slept on the bed for a while as they compress into position.

What is mattress settlement?

Mattress settlement is where the fillings of a mattress compress and ‘settle’ into position. As you sleep in the same space most nights mattress settlement tends to occur quicker in that space than the rest of the mattress.

 It’s like only sitting on one side of the sofa, when you try the other side it may feel plumper or firmer. Mattresses with very soft layers such as Wool, Alpaca or Cotton, are more prone to settlement. Therefore, constant twisting and rotating of the mattress whilst new is extremely important to even out the wear pattern to reduce and prevent undue settlement.

Even Vi-Spring, one of the premier mattress manufacturers, gives this essential information advising that initial body impressions are not a fault of the mattress but an intrinsic part of the mattress bedding in period.

Guide Mattress tolerances to settlings by Fira. Settlement Measure Guide Estimates by Type of Mattress.

Months 0-6 6-12 12-24 24-36 36-48

Ordinary Pocket / Spring 2.5cm 3cm 3.5cm 4cm 4.5cm

Memory Spring/ Pocket 2.5cm 3cm 3.5cm 4cm 4.5cm

Pillowtop Spring / Pocket 3cm 3.5cm 4cm 4.5cm 5cm

In our experience "NBF". settlement can be a cause for unnecessary concern. Showing itself

more in mattresses with a bigger span area such as king size or super king sizes

There is no official industry standard for determining whether the settlement is excessive, as there are simply too many variables to consider. Some bed manufacturers, retailers and independent inspection companies use a measuring system based on the type of mattress fillings and the age.

To add further information with regard to this I have enclosed extracts from published articles from the NBF, and other sources bellow.

"The most common issue is settlement or dipping; a luxury mattress will settle quite a bit, and if it has a topper this could be even more in the first few months”. “in particular, high-end mattresses were subject to settlement. This means that initially, body impressions would be more visible as the mattress fillings directly beneath the user are compressed”

“In our experience settlement can be a cause of unnecessary concern. Showing itself more

in mattresses with a bigger span area such as king size or super king sizes “The bottom line is that settlement and indentations are going to occur in all mattresses.

If a person was five foot wide and 6 foot high the depression and settlement would be

equalised over the entire mattress. However, people are not the same size and shape of a

mattress and, therefore, body shaped impressions will occur.”

Settlement on its own is not an indication that the mattress is failing – on the contrary, a mattress with generous layers of comfort fillings should be expected to demonstrate ‘body impressions’ and is an indication that the mattress is performing correctly.

Similar to a good pair of leather shoes, a new mattress will ‘relax’ and take on the shape of the user.

There seems to be a misconception amongst some people that a mattress should look and feel as good as new even after months or years of service – despite it supporting your body for around seven to eight hours every night.

The extent to which the mattress will show signs of settlement depends on a number of factors such as the weight of the user, the number of fillings, the type of fillings, the firmness of the mattress, whether the mattress is two-sided or single-sided.

Larger size mattresses such as super king-size (180cm wide) and king size (150cm wide) will show signs of settlement more so than a smaller size mattress. This is because there is a wider area in the centre of the mattress that doesn’t get used and the fillings don’t become compacted. This ‘ridge in the middle accentuates the sleeping areas on either side of it where the fillings will have settled or compacted during the night.

Whilst these body impressions can be quite noticeable, they are not necessarily a sign that the mattress support has failed. A mattress that has collapsed or sagged will be very evident when you lie on it – there will be a distinct lack of support, almost a sensation that you can feel right through to the bottom surface of the mattress.

The NBF recommends that you follow the care instructions supplied with your mattress to prolong its life and minimise the effects of settlement. However, you should expect your mattress to show some signs of settlement and remember that it is not necessarily an indication that the mattress is failing.