Hi Mattress Facts,
The “specs” they supplied are meaningless and covers a range from lower quality polyfoam to high quality polyfoam. If the upper layers were 2.5 lbs then they would be much more durable but in a mattress in this price range I still wouldn’t like to see polyfoam layers this thick in the all important top layers of a mattress even if they were high quality polyfoam (even high quality polyfoam is a much less costly and durable material than latex).
In the lower end of this range the use of polyfoam would be completely unsuitable in a one sided mattress in this price range.
Foam softening and breakdown is only covered by warranty if it involves actual unweighted impressions which are deeper than the warranty exclusions and in most cases foam softening and the loss of comfort and support is the reason that people need to replace a mattress … not visible impressions. You can read more about warranties in post #174 here.
I don’t think that “failure” is the issue as much as durability and the likelihood that the materials will soften outside of your range of needs and preferences (whether they have specifically failed or “collapsed” completely or not). The durability of a material is relative to the person on the mattress and when the mattress has lost the comfort and support that is specific to their needs and preferences then in practical terms the mattress has “failed” whether it would still be completely suitable for someone else or not.
If a customer had a mattress that was no longer suitable for them to sleep on because of foam softening and there wasn’t a visible impression bigger than the warranty exclusion then they wouldn’t even know about it because warranty coverage would be denied even though the customer would need to replace the mattress.
Phoenix