Memory Foam, Open Cell, Closed Cell, weights etc

Discussions General Mattresses Questions
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Commentary
Today I discovered that the density of the memory foam (LBS per cubic foot) does not necessary effect how the foam behaves, or how it feels.

I could have 6 pound memory foam that feels the same as 4 pound memory foam, however the 6 pound foam would last longer.

I was also handed a block of 4 pound open cell memory foam with a blue dye (gel swirl) from vita foam, and an older 5 pound block of regular memory foam (older) from vita. They both felt the same. But I was told that the open cell would dissipate heat better, and maybe would last as long as the 5 pound closed cell foam.

Now I am totally confused.

Basically I am looking to create a bed locally (I’m in Ottawa), and I am looking for either 3 or 4 inches of foam memory foam , and a 5 or 6 inch base with a IFD of 31 to 34 (using no less than 2.5 lb foam).

I’m 6 feet tall (exactly) and weight 154 lbs.

I did lye on a mattress with 3 inches of the new open cell vita foam in 4 lbs. The IFD must be higher on this foam because you don’t get that “sinking in” feeling as much, and more of a floating feeling. It definably relieves the pressure points.

Question

Is it better to try to go for the higher LBS memory foam ? Is the LBS per cubic foot the best measure of the quality and longevity (as I had once thought), or does newer technology offer the same durability in a lighter weight?

My options

I can get Vita foam at one local store in a 3 inch layer with either (2.5 lb vitafoam base)
-4 lbs open cell (gel foam)
-5 pounds regular memory foam

  • note the beds at this store seem very well though out and designed by a very smart people.

or

I can go to a manufacturer and get 2 or 4 inches of in house memory foam made here (in Ottawa) (any base I want, and soy based)

  • 5lbs or 6lbs of a soft (over the phone description) memory foam. I’m not sure if it is open cell or not (from Les Matales Lapensee).

Id really rather get 4 inches,…Is that too much? It is better to stick with Vita foam?

Any advice or a point to some reading material would be greatly appreciated.

Cheers

2

Hi The_brooke,

[quote]Today I discovered that the density of the memory foam (LBS per cubic foot) does not necessary effect how the foam behaves, or how it feels.

I could have 6 pound memory foam that feels the same as 4 pound memory foam, however the 6 pound foam would last longer.

I was also handed a block of 4 pound open cell memory foam with a blue dye (gel swirl) from vita foam, and an older 5 pound block of regular memory foam (older) from vita. They both felt the same. But I was told that the open cell would dissipate heat better, and maybe would last as long as the 5 pound closed cell foam.

Now I am totally confused.[/quote]

You’re certainly right about this. Density is the single biggest (but not the only) factor in the durability of memory foam (see post #4 here about the different factors that can affect the relative durability and useful life of a mattress) but it has much less to do with the feel and performance of memory foam (see post #9 here and post #8 here).

As the previous links indicated … density is the single biggest factor in durability and how long memory foam will maintain its properties but it’s only part of the picture because no matter how durable a material may be if the mattress that uses it isn’t a suitable “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and you can sleep comfortably on it then it would have little value to you. Conversely … if a mattress feels great but the materials are low quality and the mattress loses its comfort or support in a year or two because the materials are low quality then it would also have little value to you. All of this and the other factors that may be important to you in a mattress purchase are all part of each person’s personal value equation and the tradeoffs involved with any mattress purchase.

[quote]My options

I can get Vita foam at one local store in a 3 inch layer with either (2.5 lb vitafoam base)
-4 lbs open cell (gel foam)
-5 pounds regular memory foam

  • note the beds at this store seem very well though out and designed by a very smart people.

or

I can go to a manufacturer and get 2 or 4 inches of in house memory foam made here (in Ottawa) (any base I want, and soy based)

  • 5lbs or 6lbs of a soft (over the phone description) memory foam. I’m not sure if it is open cell or not (from Les Matales Lapensee).

Id really rather get 4 inches,…Is that too much? It is better to stick with Vita foam?

Any advice or a point to some reading material would be greatly appreciated.[/quote]

This would depend entirely on which one your careful and objective testing indicated was the best match for you in terms of PPP. The most important part of the “value” of a mattress purchase is PPP. After that it would depend on whether either one had any “weak links” in the design either because it used lower quality memory foam than the general memory foam guidelines I would suggest or because the density of the memory foam wasn’t suitable for your weight or body type also using the guidelines that are included in links in the tutorial post here.

If you follow the steps in the tutorial post you will have the highest odds of a successful purchase.

Posts #2 and #3 here (in case you haven’t seen them) include the better options and possibilities I’m aware of in the Ottawa area. A forum search on Ottawa (you can just click this) will also bring up some forum posts and topics with more information and feedback about some of the options there as well.

Phoenix

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Phoenix thank you. When I come home from work I will research the guidelines you have linked too. Thank you for your help !

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Hey Phoenix, I wanted to let you know that I have read all of the guides, and all of your posts, and sub-linked posts. I especially liked your post about warranties (Every sentence I was saying “halleluiah”, “halleluiah” hahahahaha). Thank you for this knowledge, and it is power to make the correct decisions.

On to the good bits

one of the companies that I mentioned above (with the connection to Vita Foam) is 7 Futons. I asked, and they delivered a quote for me with the following specs:

My stats

  • 6 feet tall
  • 154 lbs, (of yogi)
  • side sleeper (I wake up on my side, seriously)

My future bed

-5" or 6" HD poly-foam 3lbs in IDF of 32-38 (I can have anywhere in that range) (note, the floor model they have is either soft or firm, I liked the soft, and will thus get the medium foam since I have read all of your posts about durability).

  • 3.5" of 5 pound (apparently its 5.2 pound) memory foam with an IDF of 10-18

  • A nice terry towel envelope

The price too is very good, and the foam is made in Canada (Montreal) by VitaFoam (to high standards). This is a luxury item !

The only question that I still am pondering is whether to get 5" or 6" base of 3lb poly foam?

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Hi The_brooke,

I’m glad it could help you :slight_smile:

[quote]-5" or 6" HD poly-foam 3lbs in IDF of 32-38 (I can have anywhere in that range) (note, the floor model they have is either soft or firm, I liked the soft, and will thus get the medium foam since I have read all of your posts about durability).

  • 3.5" of 5 pound (apparently its 5.2 pound) memory foam with an IDF of 10-18

  • A nice terry towel envelope

The price too is very good, and the foam is made in Canada (Montreal) by VitaFoam (to high standards). This is a luxury item ![/quote]

These are all good quality materials and there are no weak links in any of them. I would let your testing and your body decide on the “comfort specs” (the ILD/IFD)

I would also treat this as a preference choice and base the decision on your personal testing for PPP because one really isn’t any “better” than the other outside of which one is the best “match” for you or “feels” better to you.

Phoenix

6

B)

7

Just wanted to say that I ordered my mattress today from 7 Futons in Ottawa.

They went out of their way to order my the 3.0lb HD poly-foam for the base (they usually use 2.5 lb), and to give me the exact amount and type of memory foam that I wanted (3.5 inches, when they usually do 3 inches)

My final specs

  • 5 inches 3lb poly-foam base (medium feel)
  • 3.5 inches 5.2lb memory foam top (opted for the 14 IFD)
  • This very natural looking sand color terry cloth stretch top.

The price was very good. (less than I expected for such a bed), and like I said above the foam is coming from Vita Foam. They also went out of the way to accommodate my foam preferences with out any hassle. I was also never pressured to purchase anything at all. The owner (Alvin) also explained to me how a warranty on a mattress is useless (he said the same things to me that Phoenix has stated on this form).

If anyone in the Ottawa area is looking for a great mattress maker, please go check out 7 Futons. They have very good Tally Latex designs too that wont break the bank.

:slight_smile:

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Hi The_Brooke,

Thanks for the feedback … and it sounds like you did very well!

All the materials are good quality and there are no weak links in any of them and it’s good to see such good service and that they worked with you to make sure that what you purchased was exactly what you wanted.

Congratulations on your new mattress :slight_smile:

Phoenix

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Phoenix, I have one more question. I have combed the forum first of course.

Also, I promise to not hold you responsible for any of my decisions.

I still have one day left to alter my order before it goes out. I will try to organize this as best as I can to make it easy to understand.

The foam that I am ordering is not foam that the store usually carries. Therefore, the core IFDs on the demo bed are not exactly like what I could order in 3.0lb (demo bed uses 2.5 lb)

Please also note that the demo beds are topped with the memory foam that I will be getting (roughly)

What Ive tested

  • (what they call firm and vita calls medium) - 32-38 IFD 2.5 lb ( I find it a bit firm but not uncomfortable)
  • (what they call light and vita calls soft) 25-31 IDF 2.5 lbs (its very comfortable, after 15 mins my side starts to be supported by the memory foam, which feels a little strange (I’m not use to that feeling)

In not sure how my alignment is in either one. The softer one feels more comfortable but a little bit too soft (just a tad), therefore my choice for the medium.

What I can order in 3.0lb

-What vita calls medium HR (32-38 IFD could turn out anywhere in that range) I assume this will feel exactly the same as the 2.5 lb with the same, IFD

  • What vita calls soft HR (28-32) the is a different IFD than the 2.5 LB foam (its a little bit firmer)

I’m trying to decide if I should stick with my selection of medium HR 3.0 foam in my base layer (that could end up anywhere from 32-38 IFD), or opt for the softer one (28-32 IFD) since I did find the medium or (as they call it firm) pretty firm.

the 32-38 idf foam doesn’t give or “indent” very much with me and this causes less of my body to sink in (i float on top). I find it a bit less comfortable. But I decided to choose it in case the soft was too soft (only to find out that the soft in the 3lb foam is "not as soft 28-32 IDF).

Since I am a side sleeper do you think that IDF of (28-32) is to little and maybe its still better to stick with the if of the medium foam (32-38) even though it feels a little firm?

Sorry if that was confusing!

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Hi The_brooke,

There are too many unknowns, variables, and preferences involved for me to answer specific questions about PPP outside of more generic or conceptual information (see mattress firmness/comfort levels in post #2 here) because I can’t see you on the mattress or feel what you feel and your own careful and objective personal testing in combination with the “real life” guidance of a knowledgeable and experienced manufacturer or retailer is much more reliable than any “theory at a distance” based on specs or body type. Your ability to test for alignment is also much more reliable than any guesses based on information about body type or mattress specs.

It would also depend on the compression modulus of each foam (which is the rate that a foam becomes firmer with deeper compression) which along with some of the other foam specs can be just as important as ILD in terms of the compression properties of the foam. Higher density foams tend to have a higher compression modulus (get firmer faster with compression) than lower density foams.

Since I don’t know all the specs of each type of foam and have no personal experience with these specific combinations I would tend to go with the guidance of the manufacturer who will have more knowledge than I do about how the different foam combinations will perform together in “real life” not just based on ILD alone.

I would tend to choose the version of the 3 lb foam that was the closest to the 2.5 lb foam you tested that was most suitable for you (assuming it has the same memory foam thickness and type as you tested on top) or was a small increment in the direction of slightly softer or firmer that your testing indicated was suitable for you. To know this you would need to have more specific ILD’s for what you tested because the range you mentioned is rather wide.

I would also keep in mind that any changes to a mattress that you have tested can sometimes have a surprising effect but again the manufacturer will have more insights into whether the two foams are comparable or how they may be different.

Other than this … the most useful piece of advice I can share is that if you are truly undecided between two different firmness levels that are close together and otherwise seem to be “equal” then I would lean towards the firmer of the two because first of all mattresses tend to soften over time and it’s also easier to “fine tune” a mattress that is too firm by adding a topper than it is to make a mattress that is to soft any firmer which would require the removal and replacement of some of the foam.

Phoenix

11

I see, then I need to find out the compression modulus.

If it is higher (gets firmer faster), then the 28-32 range would be better actually because it would mean that the firm one that I tried would be even “firmer” with the 3lb foam.

Thank you for all the time that you take to answer everyone questions. I don’t know how you do it.

Cheers

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Hi The_brooke,

I doubt you will be able to find this out and they may not even know it (and it’s not really important that they know it anyway).

I would avoid going by these kind of complex specs because there are even more specs than just ILD and compression modulus which will affect firmness and softness and the “feel” of a foam and which would have little practical meaning to you anyway.

I would go by the results of your own personal testing along with the guidance and experience of the manufacturer who will be more familiar with the “end result” of how the foam feels and performs.

Getting too involved with foam specs can lead to “paralysis by analysis” and you likely won’t be any closer to knowing how the mattress will feel for you in real life.

Phoenix

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“paralysis by analysis” This made me cackle (because upon self-analysis you are correct).

Understood, thank you.

14

FYI all done, and I feel completely comfortable with my decision : )

I chose for the 28-32 ILD base from instead (3lb). I will be perfect.

15

Hi The_brooke,

I think your rationale and “gut feel” is sound especially given your tall thin frame.

I hope you have the chance to share your feedback when you’ve had the chance to sleep on it for a while.

Congratulations once again :slight_smile:

Phoenix

16

I got it today !!!

Its just to spec, 8.5 inches total.

and I’m sure it weights 90 pounds at least.

I will update after Ive slept on it, but I had a little nap already and it felt amazing. After the memory foam heated up I sank just the right amount into the bed, and there is virtually no smell. I can only smell a hint of chemicals if I place my nose directly onto the foam, and its such a slight odor (difficult yo detect, but detectable).

You can tell that they had a seamstress make the cover too.

I cant wait to get a good nights sleep.

:woohoo:

17

Hi The_brooke,

Thanks for the update … it sounds like things are looking good :slight_smile:

Phoenix

18

Update after sleeping on the mattress for 4 nights

The polyfoam is exactly the correct firmness. I can say that with certiany

What I have noticed (and am unpleased with), is that the memory foam is much softer than in the store. It’s really strange. Its 5lb memory foam but for some reason it is very soft and squishes in quickly, and rebounds almost imediatley. So basically it offers less in the way of pressure point removal.

What I am saying is that it reacts more like a lower density memory foam would (on average).

This is totally the opposite of the memory foam layer of the bed in the store (that I was using to guage my preferance).

The end result, is that it doesnt function with the the base layer that I had selected (as planned). Good thing the base layer is amazing because that is basically what I am sleeping on (and I only weight 150lbs a 6feet tall).

I may fo back to the store and talk to the owner about it. Wish me luck, Ive had so many problems, and spent so much money in the past 2 months on bed failures. I really thought this would be the last time.

19

Hi The_brooke,

Have you tried weighing the memory foam layer to determine its density or otherwise confirmed that the foam is identical to what you tested?

I’m guessing you’ve considered the other common variables, like the store was cooler than your home or your clothes played a difference while testing.

Strictly speaking, according to Phoenix there’s nothing that says higher density memory foam is firmer or slower response.

Thanks,

20

The termperature is the same. My foam just came out softer (less force to compress).

The one in the store did not compress as much and supported better.

I guess its all in the varience. I was told that the 5lb foam had an IFD of 10-18. So I guess that means that it could turn out anywhere in that specturm. The memory foam layer in the store must have been much harder, and mine must be closer to the 10 IFD.

It’s easily felt by just squishing the foam with your fingers. It feels totally different. Also to note is that my condo is not a warm place, but cool (big windows).

The memory foam on my bed does not seem to be tremendiously affected by temperature (Im sure it is affected, but not like others Ive seen). It seems to feel the same whether or not I have warmed it up or not (just a little difference).