Mattress comfort layers - latex

[phoenix]

Hi Yodwinder.

Welcome to our Mattress Forum!

Designing and building your own mattress can be a lot of fun but can also be quite frustrating and involves a lot more knowledge of how different materials, layers, and components interact than many people suspect and I woulddo some more DIY research by reading option 3 in post #15 here and the posts it links to (and option #1 and #2 as well) so that you have more realistic expectations and that you are comfortable with the learning curve, uncertainty, trial and error, or in some cases the higher costs that may be involved in the DIY process.

The more important questions is would 9" of comfort layers at 15/19-21/24 ILD be inadequate for providing the necessary spinal alignment?

This is a good question … your “design of 15” of latex would be much more than needed at your BMI and weight for your comfort/support needs and in this case excessive thickness in combination with the plushness of the top 3 Talalay layers may be totally counterproductive. . I am not sure what the reason is for going with a 15" thick mattress , but the comfort layers in your DIY come to a total of 9" of Talalay latex layers with ILDs between 15-24. This would be much too plush/soft and may compromise your posture and alignment. This renders

The compression of each layer (mainly controlled by thickness, firmness, compression modulus, hysteresis, and position along with a few other specs) are what creates the pressure relieving cradle of a mattress in the top layers which re-distributes weight and pressure on the bony prominences and pressure points of the body while the resistance to further compression of the deeper layers is what “stops” the heavier parts of the body from sinking down too far and putting the spine and joints out of their natural alignment. The balance between the opposing needs of pressure relief and spinal alignment is the main factor behind all mattress design and theory and why different mattresses match the body types and sleeping positions and preferences of different people … or don’t.

So the key is to make your best choice in terms of the latex type and properties you are looking for (I would identify the qualities that are most important to you) and to choose the thickness that would solve the specific reasons you are looking for this material in the first place … be most suitable for your body type, sleeping positions, preferences, and the layering of the mattress it is going on, … and has the best combination of and tradeoff between cost and quality that you are comfortable with. A good starting point for a comfort layer is 2" (even less in some cases depending on what you are trying to achieve) and then add thickness if you have specific reasons to do so and if your mattress design has enough “room” to add extra thickness without compromising support and alignment.

For example a 6" of base/support system and a 4-6" comfort/transition layer system could give you all you need. It is very rare that anyone would need more than 12" thickness. The example below would be a more balanced design for an average person of your weight range that desires a thicker mattress.
6" of 35 ILD Support base
2-3" of 28 ILD transition
2" of Soft Latex (24 ILD)
1" of Plush Latex (19)
Optional 1" of 15 ILD (if you really think you want the top to be ultra-soft)

I have read that a difference of more than ~5 ILD in comfort layers can lead to feeling like you are “bottoming out”, which is exaggerated in the lower ILD offerings. The Rejuvenite or second Copper Infused topper would serve as an intermediate layer to counteract that feeling. Would there be any benefit to adding a second Copper Infused topper instead of the Rejuvenite, or vice versa?

While I understand what you “mean” by “bottoming out”, I want to comment that you won’t be compressing the stacked foams to their minimum thickness. All of the foam layers of a mattress work together, not individually or sequentially, so you’re desiring something in the transition layer that matches better with the “compressed ILD” of the uppermost layer so that this transition from the comfort layers to the base foam isn’t so abrupt, if I understand this correctly.

with 9" of comfort layers on top, would there be any appreciable difference in feeling or alignment/support between the different zones? As far as felt differences go, would one even feel a difference between Dunlop or Talalay at that point?

While you wouldn’t have any reason to be concerned with “bottoming out” even for lower ILD ranges (especially for very small +_ 5 ILD variations in firmness), your intuition is correct in that generally speaking you will “feel” more of the upper layers than the deeper layers within the mattress… Unless you are the “Princess and the Pea” type it is not very likely that you would feel much difference between the Dunlop and Talalay or the zoning all the way down through the 9" of top layers. Dunlop, of course, has a different “feel” and performance than Talalay and is less lively or springy. You can see a comparison between them in post #7 here. With thinner comfort layers some people would notice more of a difference than others with transition or support layers that used each material if the top layers were the same type of latex. I am not privy to your conversation with Arizona Premium, but I agree with their response to you… and it would make sense that they would advise you to skip the third comfort layer and go for a 12’ maximum.

Good luck and I’d be curious to know what you ended up deciding. Arizona is one of our Expert members here and you can always reach out directly to them thourh the Ask an Expert feature of our forum.

Phoenix