One-sided mattresses, or no-flip mattresses start with the supportive layer on the bottom and stack the comfort layers on top. They are built from the ground up and aren't reversible. Whereas flippable mattresses have a supportive core with comfort materials on both sides, these mattresses don't need to be flipped and only have one sleeping surface.
Years ago, most mattresses had two sides and you had to flip and rotate them. But since Simmons introduced the one-sided mattress in 2000, two-sided mattresses have been phasing out. Traditional innerspring mattresses were built around a central coil system with comfort layers on both sides of the coil system. No-flip mattresses feature a coil system base with layers of comfort materials stacked on top. This allows for twice as many comfort layers stacked on top of the coil system base and more potential to create a more comfortable mattress.
There are many benefits to no-flip mattresses. A great benefit is not having to flip a heavy mattress to ensure uniform wear. Even better, you'll have twice as many comfort layers working to relieve pressure on your body and reduce motion transfer. This is especially valuable for those who share a bed with an active sleeper. For those concerned that a no-flip mattress won't last as long as a double-sided mattress, you need only look at the warranty. You'll see that one-sided mattresses are guaranteed to last just as long (if not longer). In fact, one-sided mattresses are historically less likely to have warranty claims filed against them than two-sided mattresses.