Recommended weight for HD foam used as Core

First, thank you for this informative website. Like so many others I, too, was taken with how the iComfort Revolution felt in the showroom. But that $1999 non-negotiable price was a bit of a sticking point especially with the uncertainty of what we could expect from the mattress over its life. Thankfully, my aching back and I walked away to do more research!

We have a Denver Mattress store here in Tulsa. Since the Aspen and the Snowmass “mostly latex mattresses” have been receiving recommendations, I plan on checking these out. But, after trying to read as much as I can on this site, I have gotten a bit confused about the proper weight for the hd foam in the core.

For example, in the “Mattress support cores - Polyurethane” section, it says “High Resiliency polyfoam (HR): This is the highest grade of polyfoam and weighs 2.5 lbs per cubic foot or more. It also must have a support factor (progressive resistance) of 2.4 or higher to qualify for this grade.”

The info on the foam in the core of both of these mattresses is that it is “1.8 lb HR foam”. So, is this really HD foam? Does this number (1.8) affect the durability of this foam and if so, does it really matter? Or am I totally misunderstanding the density discussion?


I am no expert but the HR foam is of better quallity than HD foam and is a form of HD foam. Whenever you see the use or HR foam you can know that, that is the highest quallity of poly (not memory) foam and a 1.8 HR foam core is good quallity if i am wrong someone please correct me but, that is my understanding of it i hope this helps.

Hi Searchin,

Immortal has it exactly right. the lowest quality HD foam I would consider as a support base is 1.8 lb polyfoam in the firmness that was most suitable. Higher would be better. There are some mattresses that use firmer 1.5 lb foam in the base layers (and I’ve seen some that are lower yet at 1.2) but I would not consider this except in the very lowest budget range if at all.

HR polyfoam on the other hand is a high performance material and both higher quality and more expensive. It is rarely found in mattresses outside of local manufacturing. It starts at 2.5 lbs density and also needs to have a compression modulus (also called support factor and tells how quickly it gets firmer with deeper compression) of 2.4 or higher and a resilience of 60%. Foam of this quality is getting close to latex in many aspects of its performance but it is also more expensive than conventional polyfoam.


Thanks you both for the answers. I think my confusion is that the product info for the mattresses states that the core is made of “1.8 lb High Resilient” foam, but the definition/discussions is that HR foam starts at a weight of 2.5 lb. If this is so, how can a foam that has a 1.8 lb weight be called HD? This is a bit of a truth in advertising issue for me.

Hi searchin,

HR (high resilience) polyfoam is an actual classification of foam that has certain criteria attached to it before it can be included on a law tag as HR polyurethane foam. It is made with high performance chemicals and has many of the characteristics of latex. The problem though … as you noted … is that way to many people don’t have a clue about what HR foam really is and for them it is more of a marketing term which means “this foam is more highly resilient (springy) than other lower density foams”. I completely agree with you that this is very misleading. I think that many places actually use this term on purpose trying to create the impression that their foam is better than it really is. As you mention … there is no such thing as 1.8 lb HR foam although there is 1.8 lb foam that has a higher resilience (the percentage of it’s original height a ball bounces back when it is dropped on the foam) than other foams. Very confusing … and many manufacturers and outlets do much better in an atmosphere of confusion where meaningful comparisons based on accurate information is more difficult. Lower density polyfoams that use high performance chemical systems are usually called either high performance or high comfort foams but these are also not “legal” or specifically defined terms like in the case of HR polyfoam. There is ongoing debate about what each type of foam should be called and little consistency.

There are also some outlets … including some manufacturers I have talked with … that may be very knowledgeable about foams and mattress components but don’t get into technical specs as much. They just “know” better quality foam because they have worked with it for decades and know which foams will last and which will be returned with issues a few years later. In these cases they may call certain foams “high resilient” foams just because everyone else seems to use the term (including some foam reps) when technically they are not but this is more because they tend towards more experiential knowledge than detailed technical knowledge and there is not the same “intent” to mislead (and normally quite the opposite in these cases).

HD (high density) polyfoam is made with conventional polyols (one of the two main chemicals used in polyfoam manufacturing) and is just a descriptive term (rather than an actual legal term) meaning that the foam is higher density (and better quality). This too can also be misleading because many places use HD to describe 1.5 lb foam and I have even seen it used to describe 1.2 lb foam which IMO is ridiculous. In most places … 1.8 lbs is the lower end of HD and this is the density of conventional foam I would use as a minimum for a support layer unless I was in an extremely low budget range.

“Truth in advertising” or high levels of either practical or technical knowledge is certainly not the “norm” in this industry … at least in the more mainstream outlets that most people are drawn to. The one thing places like these do have lots of knowledge about (reinforced by ongoing training) is the techniques to use and how to sell specific mattresses based on the latest “story” or “endorsement” and that have the highest profit margins. They are very good at this.


Thank you for the explanation! :cheer: I think your comparison of descriptive term vs legal term is helpful in understanding why HD is used in describing this layer of foam. Now I don’t feel so much like someone is trying to pull something over on me!