We’ve been memory foam fans for over 15 years now, but that’s changing. It seems that all the memory foam manufacturers these days offer only soft-to-medium memory foam. If you want firm, you can get it in the foundation layer, but not in the memory foam layer.
That sucks, because the memory foam layer is where (I think) firmness is needed most.
Further, it used to be that you could judge firmness by density, but that corollary no longer holds true. Nowadays, a 5.3 lb density memory foam layer could be soft or medium, but it’s never firm (as far as I’ve been able to find).
The only measurement worth a damn anymore is ILD (or IFD … same thing), and almost none of the manufacturers will tell you what the ILD value is of their memory foam. They’ll tell you for the latex lower layers, but not for the memory foam. Or if they do tell you, it’s only in the 10-20 range, which qualifies as soft.
This really sucks if you want true support from the memory foam layer.
I saw a post somewhere where someone said you should get an 8 lb memory foam topper. I’d do that if I could find a firm one, but there aren’t any. Toppers these days are nearly all soft.
Anyone else run into this? Our backs and hips hurt from trying the under-firm memory foam options available today.
There have always been “firm” memory foam mattresses but there has never been any particularly “firm” memory foam. Firm memory foam mattresses generally use thinner layers of memory foam so that the firmness of the layers underneath it “come through” more. This is why memory foam has never been used in support layers because it’s not firm enough to be suitable as a support material … only as a comfort or transition layer.
ILD with memory foam isn’t particularly meaningful because the ILD of memory foam changes with heat, humidity, and the length of time it is continuously compressed and there are many other factors that contribute more to the firmness level of a mattress than just the ILD of the material … particularly with memory foam (see post #4 here). There is also more about the different properties of different types of memory foam that have always been independent of density but that can affect how firm it feels in post #8 here and post #9 here.
What is true is that much of the memory foam being sold today has a faster response and is less temperature sensitive which can both affect how firm a memory foam layer feels as well.
This has never been particularly true because any density of memory foam can be made in firmer or softer versions. For example the Tempurpedic 7 lb memory foam feels softer than the Tempurpedic 5.3 lb memory foam and there are also several versions of the Tempurpedic 5.3 lb memory foam that have different firmness levels as well even though they are the same density.
Memory foam ILD’s don’t relate or compare to the ILD’s of other fast response materials because the method that is used for testing ILD produces different results with slow response materials than with fast response materials. Memory foam has always been in “soft” ILD ranges under 20 which again is why it has never been used as a support layer.
Again … memory foam can only be used as a comfort or transition layer and its strength is as a pressure relieving layer … not as a support material. It has always been too soft to use as a deeper support layer in a mattress. There is more about primary support, secondary support, and their relationship to pressure relief in post #2 here and in post #4 here that may be helpful in understanding the difference between support/alignment and comfort/pressure relief.
What you may be looking for is some of the older style memory foam that is more temperature sensitive (takes longer to soften and feels firmer because of this) and has a slower response than many (but not all) of the newer types of memory foam. Much of this was in response to the complaints about many “old style” memory foam mattresses with temperature regulation and a feeling of being “stuck in the sand” which makes it difficult to change position. There are still many “firm” memory foam mattresses available though and because there are more manufacturers that are making memory foam mattresses than there used to be … there are also more “firm” memory foam mattresses available than there used to be as well.
I’m afraid we’ll have to agree to disagree. Memory foam layers can be supportive and have been in the past. I know because we slept on such mattresses for many years. When you lay down on a mattress and don’t sink in more than 2-3" with a 4-5" memory foam top layer, that’s memory foam supporting you. That’s what the depths of the memory foam was on our earlier mattresses: 5" on a 12" mattress, then 4" on a 10" mattress.
Disagreement is “the norm” in the mattress industry so this isn’t unusual at all although some of what you are suggesting is also factually incorrect.
This would depend on how you are using the word “supportive” because it has many different meanings. Memory foam can certainly provide secondary support (see the posts I linked earlier) and can be used in comfort layers and transition layers which are an important part of good alignment on a mattress but even “firm” memory foam isn’t firm enough to be suitable for use as a primary support layer. This is why it is ever used as the base layer of a mattress.
If it was providing good support/alignment by itself then there would be no need to have a polyfoam layer under the memory foam in a mattress because the memory foam would “work” all by itself.
Again … this isn’t correct. All the layers of a mattress compress simultaneously to different degrees although upper layers or firmer layers will compress more than the deeper layers and contribute more to the “depth of cradle” of a mattress. All the layers of a mattress will have some effect how much or how deeply you sink in to a mattress.
As someone who has used a lot of memory foam over the years, I agree with you. Overly thick and overly soft memory foam seems to be in vogue right now.