The 10 in. Tuft & Needle Diary

Hi sheep123,

Thanks for taking the time to share such detailed and thoughtful comments and feedback … I appreciate it :slight_smile:

A flexible slat foundation is an “active” part of a sleeping system just like any of the other layers in the mattress itself that compress or flex under your weight so it can certainly affect the feel and performance of the mattress. You can see more of my thoughts about flexible slat systems (such as the one that is an option with the BE mattress) vs rigid non flexing foundations in post #13 here and post #2 here and post #2 here.

In most cases using a non flexing foundation will make the mattress feel firmer but sometimes the effect of different components can be surprising for some people. There are different types of firmness and softness that some people can be more or less sensitive to (see post #15 here) and by firming up the support system under a mattress it can also “force” more of the compression to the top layer of the mattress which for some people may “feel” what they “translate” as being softer.

There is more about the most common “symptoms” that people may experience when they sleep on a mattress and some of the possible reasons for them in post #2 here.

While it’s not possible for me to know why any specific person would experience a specific “symptom” … some of the possible reasons may include …

  1. This is just part of the normal break in and adjustment period that is part of any new mattress purchase (see post #2 here).

  2. It could be connected to the flexible foundation under your mattress which could be causing your upper back or shoulders to be in a somewhat “hunched” position which can create tension in your upper back over the course of the night.

  3. It could also be a pillow issue which is pushing your head and neck forward which can also create tension or soreness in your upper back over the course of the night.

  4. It could also be connected to the mattress pad you are using which could be interfering with the response of the comfort layer of the mattress and affecting its ability to contour to the shape of your body and perform the way it was designed to. I would consider removing it for the first few weeks while you are going through the break in and adjustment period. This is also why they are using a different and more contouring cover which can take advantage of the greater contouring or “point elasticity” of their new comfort layer material.

  5. The mattress may just be too firm for you.

Again … if it’s at all possible I would start with sleeping on the mattress as it’s designed to allow it to break in and for you to adjust to a different type of mattress so that it can perform the way it was designed to. Once your experience has “stabilized” over the course of the first few weeks then I would add any additional “fine tuning” layers that you may either need or prefer depending on your actual experience at that time.

The materials will break in more quickly in the areas where you sleep the most or where you are heavier and more slowly in the areas where you sleep less often or are lighter. There is no way to quantify how much softer it will feel or how much any particular person will be affected by it because it depends on the type and quality of the material and on the body type, sleeping style, and sensitivity of the person. If the materials are good quality then it will normally be “noticeable” but not so much that it makes a major difference in the feel and performance of the mattress although again this is all somewhat subjective so different people may have different experiences on the same mattress. If someone gets a mattress “just right” when it is new the it should still be well inside the range of being “just right” after it breaks in but if someone buys a mattress that is right “on the edge” of being too soft when it is new then even a relatively amount of softening can sometimes take them outside the comfort/support range that is suitable for them in terms of PPP (see post #2 here).

It’s always a good idea to rotate a mattress on a regular schedule (see post #2 here).