Hi ohnoadrummer,
[quote]I also went to literie provinciale and bought a mattress. I got a memory foam though. Serge (the VP and presumably the same person chanpou talked to) told me that they have a 25 year warranty covering any sagging. In my amazement over this he told me that since he uses good quality foam (the memory foam is a 5lb density) that it will not sag or compress over time.
Does it seem like a reasonable claim that a higher density foam will last significantly longer, something like 25 years? (15 full, 10 prorated) I’m only about 135lbs so maybe that’s also a factor.[/quote]
Even the most durable foam materials will soften over longer periods of time (even if they don’t sag) which leads to the gradual loss of comfort and support and the need to replace a mattress but with higher quality/density and more durable materials such as 5 lb memory foam it will take much longer. There is more about the many factors that can affect the durability and useful life of a mattress relative to each person in post #4 here and the posts it links to.
I would also keep in mind that warranties only cover manufacturing defects in a mattress and not the gradual loss of comfort and support that is the most common reason that people will need to buy a new mattress so they really don’t predict how long you will sleep well on a mattress (see post #174 here).
While there is no way to quantify how long any mattress will last for any particular person, if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new and meets the minimum quality specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or even longer.
It’s always more realistic to think of about 10 years as a maximum reasonable expectation for any mattress no matter what the quality or durability of the materials and then treat any additional time after that as “bonus time” because after about 10 years the limiting factor in the useful life of a mattress will often be the changing needs and preferences of the person sleeping on the mattress and even if a mattress is still in good condition after a decade … a mattress that was suitable for someone 10 years earlier may not be the best “match” any longer.
Having said that … with higher quality materials throughout a mattress and/or for people whose needs and preferences or physical condition or body type hasn’t changed much over 10 years then “bonus time” or even “extended bonus time” with higher quality/density and more durable materials like latex or higher density memory foam or polyfoam or natural fibers is much more likely than with less durable materials.
Phoenix