overstuffing mattress case with foam layers
Dec 1, 2010 3:33 PM
Joined: May 22, 2008
Points: 171
i have a sleepez bed that I keep trying to soften by adding more layers of foam in the case. So I now have 4.5 layers in a case meant for 3 layers. The case still zips, but I wonder if I am compressing the foam so much that it is affecting the feel. I have talalay latex, which always felt springy to me, but I am wondering if this made it more springy? Or if this is bad for the foam? 
Re: overstuffing mattress case with foam layers
Reply #31 Dec 7, 2010 3:06 AM
Joined: Oct 3, 2010
Points: 809
I hope this is not too "charlie brown's teacher" like (a joke coming from another thread :))

If this is too long the short version is ... I believe any commonly used "layers" in a mattress can provide proper support and comfort but they do it with a different "feel" and in different ways. Incorrect layering or construction for an individual may result in problems with a certain material but it is not the material itself which is the culprit but incorrect construction (for the individual) or "incorrect" use of that material in a certain construction. Sometimes this incorrect use is so common that people believe that certain materials are not appropriate at all. Because of the different feels between different constructions as well, many people will have clear preferences for one "system" over another. So latex over innersprings in some cases may make it easier to get a correct support/comfort balance for some (other combinations with different materials may be more difficult to get right for them) and it may also create a feel (more bouncy and lively) that is preferred by some. So part of this is difficulty, part of this is preference.

 

Now the longer version for those who want to read more. This was also the subject of several long and interesting conversations with various mattress manufacturers....

Most springs have more resiliency so are stronger in their pushback than latex foams. For example if you were to drop a ball on a spring (assuming you got it dead on) it would bounce back higher than a latex foam. Different springs are also designed to have a different response curve in the same way that different kinds of latex or poly have different response curves. Many springs (like offset coils) are designed to compress more easily under lighter load (the "hinge" flexes) and then offer more resistance past a certain point (from the coiled spring) to keep you in alignment. This transition from softer to firmer can be more sudden than foam. Stearns and foster also has a coil in coil system which is another way of doing the same thing. The thinner taller coil flexes with less resistance at first but when you sink in deep enough, the thicker coil comes into play to keep you from sinking in too far. Even bonnell springs have a thinner part in the middle which flexes under lighter load and then when it's compressed past a certain point the coil becomes stiffer. Latex and other materials also tend to compress more easily at first and then offer increasing resistance with depth but they tend to do this more gradually and progressively. Materials or innersprings that increase more rapidly or more "suddenly" than others (have a different response curve) create a different feel but they are also easier to work with since the point they "bottom out" comes inside a narrower range and is easier to predict with differing body weights.

In terms of coils, probably the closest overall to latex would be pocket or marshall coils which flex more individually in the same way that latex can flex in a very small area without affecting the surrounding material as much. Marshall coil innersprings in other words have more "point elasticity" than other types of innerspring but still much less than latex. There are also varieties of pocket coils (different gauges, shapes, and number of turns) which have different response curves than others. The idea with all of this, whether you are using foam or innersprings, is to allow enough sinking in to distribute pressure and create alignment without allowing so much that you begin to hammock and go out of alignment.

The other part of this support "equation" is point elasticity and this is where there is a real difference between latex and innersprings including pocket coils to a slightly lesser degree. Most people tend to sink in more in their hips. They also have a more recessed area in the small of the back (back sleeping) or the waist (side sleeping). These two areas are so close together that without point elasticity the hips pushing down would also compress the material in the lumbar/waist area and there would be less pushback or resiliency where it was needed to support the lower spine and keep it in alignment (straight on the side and "s" shaped on the back). Any coil or firm material can be great at the kind of support that "keeps the hips up" ... but most are not so great at letting the hips sink in and keeping the lumbar/waist beside it up. This is where zoning schemes, marshall coils, and latex and even HR poly come into into play. They can be compressed in one place and yet still push back and support in an area that is very close by. This is also the reason that many people misunderstand the whole idea of support. The important question here is "how much and where?"

In terms of innersprings and even foams, there are two basic zoning methods which are used to allow or prevent sinking in and to support the lumbar/waist.

The first one and more common is to put stiffer coils or material under the hips to prevent them from sinking in too far. When this method is used, you also need something which will push back and support the nearby lumbar. A material like latex or HR poly over an innerspring like this can be used. A marshall coil can also be used to push back (or increase the pushback) from a deeper part of the mattress but then this pushback has to go through the right parts of the the upper layers as well. This type of support would be a little "weaker" since the hips have been stopped and the coils or the upper layers that are pushing back are less compressed and doing so more weakly. This kind of "relatively weak" pushback feels good for most people as long as there is not too much pressure on the hips (the "bottom point" didn't happen too suddenly).

The second method results in "firmer" support under the lumbar. In this method the area under the hips (and shoulders) is made softer and the hips (and shoulders) are allowed to sink more. The area under the lumbar is made firmer so the lumbar sinks down onto the firmer area and becomes more load bearing. The body's own weight is creating the "support". Laying with a suspended piece of lumber across the small of your back and balancing there would be an extreme example of this. In a case like this there is not nearly as much need for the upper comfort layers or pocket coils underneath to "push back" since there is already weight on the lumbar and if they are too resilient in that area, the combination of their pushback and the fact that the lumbar is already bearing weight may make this pushback uncomfortable or even create pain. This type of zoning scheme is more suitable for lighter people, people with unusual weight distribution profiles (such as back sleepers with a lot of weight directly over the lumbar area), or people who are able to tolerate (or even need or enjoy) more "upwards" pressure on their lumbar without discomfort.

So too little pressure or pushback in the small of the back which allows it to sink or collapse out of alignment when relaxed (like laying on a floor) ... and too much pressure in the small of the back from load bearing and/or pushback can both create discomfort or lower back pain. The method of "keeping the hips up" and using resilient and "point elastic" materials (like latex or marshall coils) for lumbar support is more common because it results in less pressure on the lumbar which is more comfortable and tolerable for most people and body profiles. The second method of "allowing the hips to sink in" and firming up the lumbar support using body weight creates more pressure on the lumbar (especially for those that are heavier or have certain body/weight profiles) and can lead to discomfort or pain for some, especially if used in combination with certain resilient materials. For others though, especially those with lighter weight or unusual profiles, it may be preferable.

So to answer your question "would inner springs with latex over it be better for some?". My answer in terms of feel is yes. Some people may well prefer the more bouncy, lively nature of innersprings.

If they do like this feel then there is always a "perfect for them" inner spring and comfort layer combination that would provide "just the right amount" of comfort and "just the right amount" of support and "weight"  on the lumbar or other areas. This may be through layering, use of materials, or zoning. Like goldilocks ... their innerspring construction can result in "not too much" and "not too little" in all the right places.

Other people may prefer the more motion separating, less bouncy, and more cradle like "softly supportive" feel of a latex core. Here too proper construction, layering, and possibly zoning can result in "just the right amount" of comfort and "just the right amount" of  support or "weight" on the lumbar. Because latex is more "progressive" and has a wider zone of bottoming out than most springs, zoning is usually less necessary but it can be a little more difficult to "get it right" in some cases.

So in the end there isn't really a "right or wrong" material. There is "easier and more difficult" to work with and there are always many moving parts to take into account. Assuming though that someone is willing to go through the time and effort it sometimes takes to get to the perfect combination of comfort and support, then which material or method of support used is really a matter of the difference in feel and preference.

Phoenix

PS: This is why, when zoning is required at all beyond the natural zoning that is built in to certain materials, I like the 2 zone approach with softer (allowing sink in) in the shoulder area and firmer (holding up) in the hip area. This keeps the hips from sinking in so far that it produces too much pressure on the lumbar but allows the shoulders to sink in enough to relieve pressure there and also slightly firm up support for the lumbar beyond what material or layer resiliency alone would provide. My second favorite would be 3 zone with the hips firmer and using natural zoning and resiliency of materials and layers to provide support for the lumbar. My least favorite would be multiple zoning beyond 3 or "reversed zoning"  which I would only use in more extreme and unusual circumstances or with the use of low resiliency materials.

This message was modified Dec 7, 2010 by Phoenix
Re: overstuffing mattress case with foam layers
Reply #32 Dec 8, 2010 2:17 PM
Joined: May 22, 2008
Points: 171
OK, so my guests are gone and I can start experimenting now. Just out of curiousity tho, I took some photos of the last setup I had (which was a cuddlebed over a mem foam pad on top of mattress, upsidedown latex convo foam over soft talalay latex over med talalay latex over med dunlop latex). As you can see (I hope) from the photos, after 4 nights the cuddlebed completely hammocked around me - and thats one of my biggest beefs with mattresses - I hate sleeping in a depression. But when I peeled back the cuddlebed it also looks a little like the mem foam might be doing something similar - certainly its higher in the middle. The last 2 pictures are the mattress without any toppers and even it looks like its doing this slightly (probably the mattress cover and not the foam in the mattress)?

The above config actually felt ok for a few nights, at least until the cuddlebed hammocked. Altho my back and shoulders are both a little sore. I think tonite I will just remove the cuddlebed and try the mem foam over the mattress alone...

http://s1025.photobucket.com/albums/y311/st3v3k4hn/sleepez/

Re: overstuffing mattress case with foam layers
Reply #33 Dec 8, 2010 2:29 PM
Joined: May 3, 2008
Points: 827
removed.
This message was modified Dec 15, 2010 by Leo3
Re: overstuffing mattress case with foam layers
Reply #34 Dec 8, 2010 2:45 PM
Joined: May 22, 2008
Points: 171
Well we have an allergy cover and a "fitted" sheet but both are designed to fit up to 18" mattresses so they are loose. I usually tuck them in but don't worry about that while I am rearranging.

As I said I had a cuddlebed and a 1" memory foam topper on the mattress, just removed the cuddlebed. Thinking I'll leave the memory foam because altho I hated a thick mem foam mattress the 1" layer does seem to help with pressure points.

 

I removed some layers to reduce the compression in the mattress and now have the following layers inside the mattress cover:

  • soft conv. latex,(upsidedown)
  • soft talalay (sleepez, ~23 ILD)
  • med talalay (sleepez, ~31 ILD)
  • med dunlop (sleepez)
Re: overstuffing mattress case with foam layers
Reply #35 Dec 8, 2010 2:57 PM
Joined: May 3, 2008
Points: 827
st3v3k4hn wrote:

Well we have an allergy cover and a "fitted" sheet but both are designed to fit up to 18" mattresses so they are loose. I usually tuck them in but don't worry about that while I am rearranging.

As I said I had a cuddlebed and a 1" memory foam topper on the mattress, just removed the cuddlebed. Thinking I'll leave the memory foam because altho I hated a thick mem foam mattress the 1" layer does seem to help with pressure points.

 

I removed some layers to reduce the compression in the mattress and now have the following layers inside the mattress cover:

  • soft conv. latex,(upsidedown)
  • soft talalay (sleepez, ~23 ILD)
  • med talalay (sleepez, ~31 ILD)
  • med dunlop (sleepez)

removed.

This message was modified Dec 15, 2010 by Leo3
Re: overstuffing mattress case with foam layers
Reply #36 Dec 8, 2010 3:18 PM
Joined: Oct 3, 2010
Points: 809
OK, that's a decent place to start.

Removing the medium talalay would probably have given us a lot more information but I also understand your reluctance (given what I did to Leo :)). The reason I think it might have been OK is that it's not too likely you'd sink through 4.5" on top (probably closer to 4" because of the convoluted) and how much you were able to feel the dunlop under 4 - 4.5" would have given us a pretty good idea of the depth of your critical zone. Even if you only sank in to the Dunlop 1/2 an inch it would likely still feel pretty soft (Unlike the 2" over Leo's dunlop where she was sinking into the dunlop more ... and too much ... which made it really firm.)

I suspect this layout may allow you to sink in too far and perhaps feel too squishy. It would be more like the feel of "soft progressive latex" than an innerspring with a nice soft layer on top that would keep you pressure free and in alignment. My guess is that you need softer/thicker than "normal" over firmer than normal underneath. Lets see how this goes though and go from there.

Phoenix

This message was modified Dec 8, 2010 by Phoenix
Re: overstuffing mattress case with foam layers
Reply #37 Dec 9, 2010 2:21 PM
Joined: May 22, 2008
Points: 171
Phoenix wrote:

OK, that's a decent place to start.

 

Removing the medium talalay would probably have given us a lot more information but I also understand your reluctance (given what I did to Leo :)). The reason I think it might have been OK is that it's not too likely you'd sink through 4.5" on top (probably closer to 4" because of the convoluted) and how much you were able to feel the dunlop under 4 - 4.5" would have given us a pretty good idea of the depth of your critical zone. Even if you only sank in to the Dunlop 1/2 an inch it would likely still feel pretty soft (Unlike the 2" over Leo's dunlop where she was sinking into the dunlop more ... and too much ... which made it really firm.)

I suspect this layout may allow you to sink in too far and perhaps feel too squishy. It would be more like the feel of "soft progressive latex" than an innerspring with a nice soft layer on top that would keep you pressure free and in alignment. My guess is that you need softer/thicker than "normal" over firmer than normal underneath. Lets see how this goes though and go from there.

Phoenix

OK, well I forgot how much I hate sleeping directly on memory foam (its ok under a layer, like under my wool topper). Slept for an hour or 2 and woke up stiff and uncomfortable and sunk thru the foam. Removed it and spent the rest of the night on just the mattress. Slept ok the rest of the night. Stiff this morning but willing to try again. Or would you prefer I remove the middle medium talalay and try that tonite?
 

Re: overstuffing mattress case with foam layers
Reply #38 Dec 9, 2010 3:03 PM
Joined: Oct 3, 2010
Points: 809
If I had the preference, I would remove the medium Talalay. We could get a lot more information that way and it would be a litttle less "random". The first thing I am trying to determine is how thick and soft the comfort layer needs to be and with the medium talalay under the soft it will be much harder to tell the effects of just the top two (3" + convo) layers themselves (the medium talalay would feel soft under them and it would be easy to assume that the softness was coming from only the softer upper layers). With the firmer denser Dunlop under these, it will be easier to tell if you are "going through" the softer upper layers. Typically. a 3" soft layer and a 1.5" convoluted would be plenty of thickness for almost everyone and the only question for a layer this thick would be how far you sink into it and it's ILD.

The absolutely greatest amount of information we could get about the comfort layers would be the 4.5" on wood ... but I wouldn't want to do that to you (laughing).

Phoenix

This message was modified Dec 9, 2010 by Phoenix
Re: overstuffing mattress case with foam layers
Reply #39 Dec 9, 2010 5:47 PM
Joined: May 22, 2008
Points: 171
Phoenix, I'm loathe to totally remove the med talalay layer just because the mattress cover wouldn't be full and i think it would be very uncomfortable trying to sleep in the collapsed cover. Wouldn't it be pretty much the same if I swapped the 2 mediums? ie put the med tatalay on bottom and the medium dunlop on top of that? Then the soft talalay and the convo foma on top of that? That way mattress is still "full" but the 2 softs are on the medium dunlop. If you really think thats not as useful I'll try it your way tho....

By the way, I wouldn't want to sleep all night on the floor but as a test I wouldnt mind pulling the 2 soft layers out and putting them on the floor to see how it felt. I could maybe nap on it for an hour? Would that actually be useful? I don't have a cover for the foam layers tho, I thought you're not supposed to lay them directly on the floor or sleep on them or handle them alot without a cover...

Re: overstuffing mattress case with foam layers
Reply #40 Dec 9, 2010 6:02 PM
Joined: Oct 3, 2010
Points: 809
Part of the problem with just swapping out the medium layers is that the "critical zone" I've been talking about is about finding out the suitability of the comfort layers. All the layers in a mattress compress to some degree when you lay on it but the compression is not as "point specific" in the deeper layers and a medium Talalay under a medium dunlop would be very different from the Dunlop on a firm surface. It would be much more difficult to tell where any specific effects were coming from.

Latex layers should definitely be covered for normal use but having them out for a short time would be fine. If you are game, then putting the two top layers on a blanket over and under on the floor could tell us a lot. If you lay on it in all your sleeping positions and sort of "bounce" just a little, especially with those parts that may have pressure issues (hips and shoulders), then "how much" you feel the hard floor underneath in different positions can tell us a lot. Take your time  and give yourself time to relax and be still in all positions. Do the "bouncing" gently while you are laying down on your side and back (rather than "all at once" or jumping on or turning over suddenly or propping up on your knees or elbow).

This could really help.

Phoenix

This message was modified Dec 9, 2010 by Phoenix

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