Building a latex over polyfoam mattress

[phoenix]

Hi Drew99GT,

I’m in the process of researching/shopping for a DIY latex over foam type mattress.

If you are attracted to the idea of designing and building your own mattress out of separate components and a separate cover then the first place I would start is 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. While it can certainly be a rewarding project … the best approach to a DIY mattress is a “spirit of adventure” where what you learn and the satisfaction that comes from the process itself is more important than any cost savings you may realize (which may or may not happen).

If you decide to take on the challenge then I would either use the specs (if they are available) of a mattress that you have tested and confirmed is a good match for you in terms of PPP as a reference point (the same type and blend of latex in the same thickness and firmness levels and a very similar cover which can also make a significant difference to the feel and performance of a mattress) or use a “bottom up” approach (see post #2 here).

My main concern is what to use for the support core. I’ve been looking at Foambymail and I’d like to use the highest grade foam available so this frankenmattress will last 10+ years. I’ve had no luck with even expensive innerspring mattresses lasting 5 years…

If you are planning to order from Foambymail (FBM) then I would read this post and this post and this topic (about their polyfoam and sources) and this post (presumably from a past employee) before buying anything or considering them as a reliable supplier.

So first of all, what density/ILD polyfoam is used for support cores of other types of latex or memory foam over poly foam?

It can vary from 1.5 lb density to about 3 lb density. Higher densities will be more durable until you get to about 2.2 - 2.5 lbs at which point the relative durability benefits of higher densities would be diminished. You can see the minimum foam density guidelines I would suggest in post #4 here.

What is the ILD and density of the foam in the support core of their top of the line mattress?

They don’t provide the ILD/IFD information for their mattresses and have also stopped providing density information as well but the foam densities of their support cores would be in the range of 2.0 - 2.2 lbs although some of them can be as low as 1.5 lb density.

Foambymail has 2 premium foams I’d like to use. One is Lux-HQ foam with 2.8 lb density and 50 ILD. I’d like to use that as it seems it’d be the most resilient, but will it be way too firm??? The other is HD36-HQ foam with 2.8 lb density and 35 ILD; will this be too soft? I’d like the overall mattress to be about a 7 on a scale of 1 to 10. So of the above support core foams, which would be closest to what premium mattress manufacturers use for their support cores? Are there other resources for obtaining a super high quality support core foam with varying density/ILDs? Like I said, I’d like about a 7 on the firm side. Thanks for any help!

I would keep in mind that every layer of a mattress will affect all the other layers and the mattress “as a whole” so there isn’t a “best” firmness level for any single component of a mattress because it will depend on the person and on the specifics of the mattress. The only way to know for certain which firmness would be best for you will be based on your own personal testing or experience.

In addition to this ILD/IFD by itself is only one of several factors that can affect the softness/firmness of a material and there are several specs besides just ILD/IFD that can affect how soft or firm a material or a mattress feels. In many cases using ILD/IFD by itself as the main point of reference can be very misleading (see post #4 here and post #2 here).

There is more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress (or a mattress/topper combination) in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.

Different people can also have very different perceptions of firmness and softness compared to others as well and a mattress that is firm for one can feel like “medium” for someone else or even “soft” for someone else depending on their body type, sleeping style, physiology, their frame of reference based on what they are used to, and their individual sensitivity and perceptions. This is all relative and is as much an art as a science. There are also different types of firmness and softness that different people may be sensitive to that can affect how they “rate” a mattress as well (see post #15 here). In other words you will always need to test a mattress for you to assess how firm or soft it feels to you (hopefully using the testing guidelines in the tutorial post) regardless of whether it feels firm or soft to someone else or how anyone else may “rate” it.

While I wouldn’t particulary trust the specs from FBM … an “average” ILD/IFD for many mattresses would be in the range of the low-mid 30’s although you will often see some that are softer (high 20’s) and some that are firmer (40’s) that can also work well depending on the specifics of the mattress design and how all the layers and components work together with the body type and sleeping positions of a particular person.

Phoenix