Mattress Forum

The advantage of the convoluted upside down is that it is closer to what I would think you need for a comfort layer. With just 1" of memory foam and the soft latex, you may feel the firmer layer underneath as the memory foam won't stop the sinking in ... and as you mentioned it may also feel harder with what's on top of it even though you would eventually sink through it anyway ... but either place would be a good beginning. The feeling you have with the convo on top may just be because you have too many relatively soft progressive layers and you get that "squishy" or "sliding" feeling overall. If it's the bumps, then upside down may help.

If the feeling you are describing is what I think it is, then it's usually caused by deeper layers in a mattress. Adding a topper like the convo could still lead to this but what would be happening is the deeper layers would be responding differently and creating the feeling. It would be easy to think it was the topper (because that's when it was happening) rather than the thickness on top of the support layers changing which part of the support layers was supporting you and how they were "reacting". They would be less compressed and if they were not firm enough you would get this feeling. Whatever it is though ... it would be well worth testing.

Yes ... when I'm in the US ... I'm in Gig Harbor near Tacoma. I'm currently in Canada though ... sigh.

Phoenix

Every change in layering needs to take into account the probable effect on all the different layers in the mattress.

Phoenix.

In general terms ... you can create a construction that works for side sleeping including as you relax more and also make it work for back sleeping. Stomach / side is a little more difficult to do without zoning. Latex (and even some polyfoam) has a wide progressive range of resistance (connected to sag factor) which means it has a range of sleeping positions it can support but each layer plays a different role in each position. To do this you have to have a sense of how far into each layer each position "bottoms out". Beyond this range you would likely need zoning.

I would probably need to know other combinations you have tried and what happenned and a bit more about the springs and poly above them as well to be more specific but it looks to me in general terms like you need thinner overall layer(s) of soft on top ... possibly a thinner layer of firm below that (depending on the springs and what was already on them) or perhaps just a single softer layer directly on the mattress foam and springs.

Phoenix

If you look at the 7" layer of 1.5 density 43 ILD with nothing on top you will see that it provides more pressure relief for certain parts of the body than much softer layered constructions. This is becasue of it's lower sag factor (allows more sinking in) than some of the softer higher sag factor foams. A lot of thought can go into understanding what is happening with the different constructions illustrated here and understanding "why" there are so many counterintuitive differences in pressure relief. This chart is for back sleeping as well which is "easier" than the greater differences in profile with side sleeping. If someone was using ILD alone to make their mattress with these materials, they would almost certainly have some "issues". Sag factor, and resiliency, and layer thickness plays a major role in mattress construction.

Phoenix

I sent you a PM with long list of what I have done in terms of layering.
 

Two quick questions ...

Could you check your underlying mattress by laying or sitting on it and moving around a bit and pressing on it in different places to see if it seems like it is consistently firm throughout.

In your PM your second layout was this:

3/3/09 Firm Dunlop latex, 1" Natura pad. No hip pain, no shoulder pain, legs good, no back pain.

It didn't say what happened to cause you to change this. Can you remember why you changed this one?

Phoenix

Well I didn't have time to check this yesterday so I slept on the config I described (mf over soft over med over med, no toppers). It felt pretty firm but I fell asleep ok. However I woke at 4 feeling soreness in my shoulders from side sleeping. Got up for a while and when I went back to sleep I think I mostly slept on my back. Have a bit of a backache this morning, which is unusual (in the past thats been a sign of too many soft layers, but I dont think it means that here?). I think Leo's points are valid; I tend to sleep on my back and side, want things really soft for side sleeping but probably need things a bit firmer for back sleeping. I also have another problem - altho I've only had the foam a few years it definitely feels softer to me in the hip area and harder at the middle and edges where no one sleeps. Maybe this is because I am heavy (230-ish) but it seems to be true even on my wife's side. So I hesitate to buy more really soft foam because I don't know how well it will last.

Anyway, given that these 4 layers felt too firm, do I really want to try just 3? My wife can sleep on almost anything but she gets pretty tired of me ripping things apart all the time, and I don't know that she would sleep on a loosely filled 7" mattress.
 

Thx again...

Yes please (smiling). And preferably with the convoluted latex on top.

Since you would not be bottoming out onto your base with 4 layers, the "firmness" is coming from an inside layer. It's always best and easiest to find a simple reference point first and work from there. This more simple beginning point will do a lot to help decide where to go from there. I'm "targeting" certain layers to gain information.

Before we start, are you sure your wife will be OK with this as we will likely be making a few changes to test effects over the next week or so. I would suggest trying each layering scheme for 2 nights unless it is so uncomfortable that you can't go to sleep on it.

Phoenix