How Long Is The Expected Life Of A Memory Foam Mattress -- Will It Last?
This isn't an easy question to answer, since it the durability of a memory foam mattress is dependent on a few factors.
The first is the density and quality of the core foam. The core foam is the base foam that sits below the memory foam, and is typically 5" - 7" thick.
Unfortunately most inexpensive memory foam mattresses and even some of the more expensive ones go with fairly low density core foam. So in terms of density, these mattresses typically are having core foam with densities of 1.6 lb/cu ft to 1.8 lb/cu ft, or perhaps lower.
Why does this matter? Because over time the core foam, which provides the support layer of the mattress, will tend to break down over time if it is of this lower density foam. To make sure a foam mattress is durable, and last 10+ years, I liked our mattresses to have core foam densities of 2.2 lb/cu ft or higher.
But it is a lot more expensive to put together a foam mattress with these higher density core foams, so just be aware that a fairly inexpensive memory foam mattress is very likely to have low density core foam and may well not be that durable over time.
Beyond the core foam, there is the memory foam layers which sit on top of the core foam.
And for the memory foam layers, I liked to see a density of 4 lb/cu ft and higher -- both in order for the memory foam mattress to be durable, but also because memory foam of 4 lb/cu ft and 5 lb/cu ft densities is the sweet spot in terms of comfort and conforming nature.
In my experience, if you put together a memory foam bed with this sort of quality foams, it can last over time in a way that inexpensive memory foams can't match.
What sort of useful life should you expect out of a memory foam mattress using these sort of higher quality core and memory foams? I found that manufacturers were comfortable giving a 10 year warranty for a memory foam mattress meeting these specs, and I had a very low rate of warranty issues with these mattresses.