Hi rh,
I switched your post to a new topic since it appears that your issues may be more connected to your mattress than to the foundation.
I have no idea what may be happening because even low quality polyfoam wouldn’t normally develop visible impressions that quickly much less latex.
I would echo hmorneau’s comments that the first place to start would be more specific information about both you and about the materials inside the mattress you are sleeping on (see this article for the specs that would be helpful).
If you know the ILD of the latex that may be helpful as well. If you are having issues that quickly then it’s more likely that the mattress is too soft for you in the first place than it is that the materials themselves are softening or impressing.
While I don’t have enough information about either you or the mattress to really make any meaningful comments or guess what may be happening … it sounds like your mattress may be too soft for you (either in the thickness/softness of the comfort layers or the firmness of the support layers).
If you can post the specifics of all the layers in your mattress from top to bottom on the forum it could certainly be helpful.
Latex doesn’t come in a specific ILD that is the same at every point across the sleeping surface but the small ILD variations in different spots across the layer aren’t something that most people would feel (see post #6 here).
There is certainly an adjustment period for any new mattress (in the range of 30 - 90 days) where the sensations you experience may feel “odd” to you at first or you may be overly sensitive to the “feel” of a new mattress that is quite different from what you are used to sleeping on but it would be highly unusual that you would have two defective latex mattresses in a row.
It’s also not unusual that a relatively small amount of flex in a foundation can have an effect on some people that are more sensitive. This wouldn’t be a loss of support which wouldn’t normally happen in a week and would be more about not having the support/alignment you need in the first place even if you didn’t notice it for the first week.
You can see my thoughts about a solid surface vs a slatted surface in post #10 here. If I was in your shoes I would first take a more detailed look at the mattress before trying to solve the issue with a different foundation … especially since you also noticed issues when the mattress was on the floor.
While I have seen the comments about innersprings being a “safety” issue … I have never seen any specific evidence that this is the case other than some very non specific anecdotal stories that don’t provide any evidence that would relate to innersprings or metal frames. Having said that … there are certainly many good quality wooden platform beds or foundations for those that don’t want to take the chance. I would personally be more cautious with “active” electromagnetic fields (such as living close to high tension wires, holding a cell phone too close to your head, or sleeping near active electrical fields or wiring as examples) … but I personally wouldn’t have any issues with sleeping on an innerspring … but that’s only my own personal opinion.
Phoenix