DIY Mattress design theories - when to put a firm layer on top of soft layer?

[phoenix]

Hi amnj,

Typing this out I’m remembering that I had an idea to try 2" of 75kg/m3 with 1" of N2 Talalay on top to see if that helped fill in that lumbar gap. I also remember wondering if our planned wool mattress protector (St Dormier) would be enough cushion to provide the needed lumbar support. I didn’t order the protector yet. Could 1" of cushioning (Talalay or wool) even help enough with lumbar support?

I’m doubting that there is an actual “gap” in your lumbar region with the configurations you’re describing. And I don’t think that what you’re describing as a lack of lumbar support is necessarily that. This would be you sinking in as if you were in a hammock, but you even state that with a firmer layer on top you had “no lumbar support”, so you are obviously describing a bit of a different sensation here, but I can’t “feel what you feel” so this description leaves me a little puzzled as to what you’re attempting to convey. Perhaps that things don’t feel “substantial enough” under your lumbar region?

I wouldn’t know if the configuration with the extra 1" of latex you’re thinking of trying out would work or not – that can only be determined through your own careful personal testing. I can tell from what you’ve been describing that the only configuration that moved you closer to comfort was with a firmer layer on top, and it is common that people choose too soft upper comfort layers and you may have specific needs for something more substantial in the uppermost layer. Plus, you’ve mentioned numerous times you don’t like a squishy feel on top of the mattress.

I feel very torn about Talalay vs Dunlop on top because I love the feeling of how Talalay relieves pressure but at the same time think that it contributes to that dreaded quicksand feeling and having a hard time changing positions. I thought that the N3 Talalay would have a very similar firmness to the 75kg/m3 Dunlop, so it was surprising to me that it seemed to be too soft when the 75 Dunlop seemed too hard

If you like the more buoyant feel of Talalay latex, you may wish to try a Talalay topper in the upper 20s/lower 30s ILD range.

Am I correct in thinking that if I’m waking up with hip flexor soreness that means my hips are sinking in too far so my body is no longer lying straight but is instead in a slightly bent/seated position?

I can’t diagnose what may be causing your hip pain on an online forum. You could be pressure sensitive in your hip area because you are sinking in too much. You could be pressure sensitive because you are sinking in too little and the surface area is too hard (this doesn’t seem to be the case). It could be an issue that you are not very flexible in either your hip flexors or your iliotibial band, and this combined with sinking in too much could be an issue when the two add together to the problem. I also have no idea how long you’ve tried each configuration to give your body a chance to adjust and lose some of its “false firmness”.

Then for Dunlop there is one density I haven’t tested and that’s the 70kg/m3. I also considered going up to a 10" mattress design by doing the 6" core plus two 2" layers on top, which opens up a giant can of worms as far as possibilities.

I wouldn’t go softer on top, as you had a positive result moving to a firmer upper layer. And if you’re complaining about “no lumbar support” it doesn’t necessarily make sense to soften up the upper layers.

You may wish to try a firmer Talalay on top, and perhaps the medium Dunlop beneath that to provide a more supportive transition layer. And whatever configuration you test, give it at least two weeks before changing, as it will take some time for your body to adjust. You can be surprised as to what feels too firm in one week becomes more comfortable in the second week as your body adapts. All of this is part of the trial an error of creating your own DIY mattress. Hopefully some of this information helps you out and points you in a better direction.

As far as topper that can be returned, here is a list of a few of which I am aware.

Phoenix