Hi Jeremy,

Many thanks for your question about John Lewis mattresses, in particular, if they should sag and become uneven after a months use.

The quick answer is no they shouldn't be so uneven and saggy so quickly. Let's delve a bit deeper into mattress settlement and how to fix or prevent an even mattress.

Mattress Settlement Explained:
All mattresses will settle over the first 3- 6 months of use. This is because the fibres compress and will reach their final resting point. This is natural will all upholstery whether a mattress, bed base, sofa or recliner.
The way to prevent this becoming an issue, as it may have for you, is by following two top tips with a new mattress.

1. Choose a two sided mattress
2. Turn and flip the mattress each month

It really is important when choosing a new mattress that you pick a two-sided model. This then means you have two sides of the mattress that you can use. Meaning twice the sleeping surface to play with to even out mattress settlement.
This also means that you can turn and flip the mattress. This helps even out the settlement and prevent you from sleeping in the same position each night which over time leads to settlement/dips on those very spots where you frequently sleep.

We are creatures of habit when we sleep so rotating and turning the mattress helps even out this natural settlement. It's particularly important during the first year of mattress ownership. After this all settlements should have occurred. By turning the two sided mattress you help spread this out over the whole mattress surface and not just one part.

Given the issues you're having with your John Lewis mattress it may be that either the spring tension is incorrect for your body weight. It's important when buying a quality mattress that you choose the spring tension based on the weight tolerances of the spring gauges. Spring tensions don't relate to the feel of the mattress but the support they provide. So a medium gauge pocket spring doesn't actually mean a medium feel mattress. A lot of people get confused by this.

The feel of the John Lewis mattress is always provided by the upholstery layers and not spring tension. Have a look below at the different fibres and how each feels. The way they are layered results in the feel.

What to expect based on your mattress budget:

We can appreciate Jeremy that you may have spent a considerable amount on your John Lewis mattress. If it has sagged its worthwhile getting in touch with them directly to discuss how to remedy the solution. We have also provided below a solid idea of what to expect for your budget and how what may feel like an expensive mattress may actually still only be entry-level once all the marketing and advertising costs have been taken off them.

Our advice would be to get in touch directly with John Lewis and ask for an inspection of the mattress as it shouldn't be sagging so quickly. Also, check that the spring tension is suitable for your body weight.

We hope that helps and gives you further mattress buying guidance. If you have any more mattress related questions please get back in touch on info@localhost or 0161 437 4419.

Sleep well!
John & Ryan