I started simple on my DIY build with the idea that I’d be able to add layers to adjust once i tried it out. This is just for a guest bed so it doesn’t need to be perfect, just middle of the road to be relatively comfortable for the majority of guests. To start i have: 5" HD-36 poly foam base 3" 5lb memory foam
I think where this went wrong to start is that the 36 ild base is really quite soft. The customer support assured me i received the correct foam, but i thought it was supposed to be a very firm base layer when in reality it’s soft enough to be used on its own. By comparison, my Tempur-pedic pro-adapt medium is substantially firmer, and that’s even with layers of memory foam (obviously).
The 5lb memory foam has a really nice feel, but it’s also what i would describe as very plush instead of “medium”, though they do not provide an ild that i could find. Again this feels dramatically softer than our Tempur, although that feel could be skewed by what I’m assuming it’s a much firmer support layer in the tempur mattresses. I don’t see any issue with the memory foam on its own, it feels great, but combined with the poly base, you end up sinking a bit into the poly instead of getting the proper support from the base layer.
Any thoughts on how to increase firmness? Any reason we can’t add a layer of more firm poly in between the base and memory foam? Or a layer of firm latex (this was the original plan)? Foam By Mail suggested a layer of their firmest foam at the very bottom, but I’m struggling to see how that would help.
Foambymail is not a particularly good place to get foam and many have had issues with getting what they actually ordered…I’d be surpised if you really got a 36 ILD foam at all which is why it likely feels so soft compared to the foam on your Tempurpedic.
Any idea of a reasonable way to confirm ild? I have some various weights but per the proper spec of measuring i can’t do that. I contacted the company but they simply told me it must be correct per the weight of the package, which obviously is irrelevant to the actual ild of the material.
If i can’t get an exchange, and regardless of whether the reported ild is correct or not, any suggestions on if i can add an additional firmer layer somewhere to help? I can always replace the base or memory foam layer entirely if needed, though I’d prefer not to.
Yes, I’ve done a fair bit of testing at home for ILD and while this doesn’t really reproduce the real test I’ve found this empirically to approximate the results. The real ILD test obviously requires expensive equipment but I’ve found you can at least get close if you are careful. What I did was to cut an 8" circle out of 3/4" plywood and then stacked known weights (digital scale is helpful here) on it until it reaches 40% compression (roughly 2" height change on a 5" layer). I lay another piece of 3/4" plywood right next to the circle and measure the difference in height (helps to use the depth end on a cheap set of digital dial calipers to do this). Once again keep adding weight until you get the required height difference. Also use a level to make sure the weights aren’t tilted or alternatively you can just take an average hight reading from opposite sides of the circle. The amount of weight you added to reach 40% compression will be your ILD number (which as you pointed out has absolutely nothing to do with density). This should get you what you need to quantify the ILD on any foam layers you want to test at home so you can compare them relatively accurately. Let us know what you find out.