Latex Mattress Construction Questions

Hi Phoenix

Thanks for all the info provided here. I’ve read most of it, and it’s been very helpful.
I do have a few questions.

First, I’m female, 5’7” and weight 235. I shattered 3 lumbar vertebrae about 20 years ago, so my back needs to be babied. I’ve slept on firm to extra firm tight top mattresses for most of my adult life, and due to the back issue, I’m more than 90% a back sleeper. I will sometimes roll over onto my side early morning, but that’s occasional and not too comfortable for my shoulders and neck. But I’m finding as I add years and lots of pounds, the current mattress is a) hitting all my pressure points, and b) my lumbar spine isn’t getting the support it needs anymore.

I’ve read all your posts about PPP and the advantages of latex, and have decided on latex.
My questions aren’t about comfort, they are more about physics. :unsure:

I’ve been doing a lot of research on manufactures and mattresses in my area, but so far have only tried one bed in person. I was only on it for 5 minutes or so, and need to go back and test for a longer period, but it was super comfortable. My lumbar is very sensitive to support, or the lack thereof, and the mattress was firm like I prefer, wonderfully supportive, and there was still some give for my shoulders when I side sleeper tested.

Finally, my concerns about construction. Since the owners have the display bed on a platform with slats about 5 inches apart, and are telling me they’ll make me a foundation (I’ll need a foundation as well) with a solid plywood surface, I hesitate when it comes to mattress composition.

• Latex is Talalay from Latex International. The store says it’s natural latex and quotes ILD, but I’m not sure if it’s Classic or Natural as per LI.
• 6 inch, ILD 36 core and 2 Inch ILD 36 comfort layer.

Again, the bed was super comfortable for me, so I’m not asking comfort questions, not that you could answer them anyway.

Is it weird/ wrong from a purely technical standpoint to have matching core and comfort layers? Given my weight, is a two inch comfort layer enough, or does that even matter when the core is the same ILD? I’ve also read on another site that in my weight range I should be looking at a mattress that is 9 inches minimum. Is that a concern given the makeup of this mattress? The store only builds up in 2 inch increments, so I don’t want to jump to 10 inches if 8 is enough.

Hi EC512,

Comfort layers are normally a softer than the deeper layers in a mattress and your top 2" are firmer than most people would normally choose but it’s not “weird” at all to have the same firmness for both layers if your testing confirms that combination is the best “match” for you in terms of “comfort”, firmness, and PPP.

While I can certainly help with “how” to choose … It’s not possible to make specific suggestions or recommendations for either a mattress, manufacturers/retailers, or combinations of materials or components because the first “rule” of mattress shopping is to always remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort”, firmness, or PPP or how a mattress will “feel” to you or compare to another mattress based on specs (either yours or a mattress), sleeping positions, health conditions, or “theory at a distance” that can possibly be more reliable than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).

The thickness of a mattress or the number of layers or the thickness of any individual layers inside it is really just a side effect of the design and the design goals of a mattress and the thickness of any individual layers or the complete mattress is also only one of many variables that can affect the feel and performance of a mattress relative to any particular person (see post #2 here) and by itself isn’t particularly meaningful (see post #2 here). In some cases higher weight ranges (or a higher BMI) will sometimes do better with a mattress that is thicker than lower weight ranges or a lower BMI (see post #14 here for more about the effect of thickness) but even this depends more on the specific design and combination of materials in the mattress and on how well your testing or personal experience indicates the mattress “as a whole” matches your specific needs and preferences in terms of comfort, firmness, and PPP than it does on just the thickness itself.

Because of the effect of thickness … a 6" 36 ILD support core with a 2" 36 ILD comfort layer on top of it will feel different than just a 6" core by itself because thickness is one of the factors that can affect the feel and performance of a mattress so the combination may be suitable for some people that are in your weight range and have a similar sleeping style but may be unsuitable for others that are also in your weight range and have a similar sleeping style as well.

Every layer and component of a mattress (including the cover and any quilting materials) will affect the feel and performance of every other layer above and below it and the mattress “as a whole” but the only way to know which combination of layers one would be “best” for you (regardless of whether it would be “best” for someone else) in terms of “comfort”, firmness, and PPP will be based on your own careful testing and/or your own personal experience.