Hi siegbenn,
Welcome to The Mattress Underground, and thanks for coming back to share a long-term update on your Purple.
It’s great to hear that the Hyper-Elastic Polymer grid is still intact and performing well after 7.5 years. Long-term reports like yours are relatively uncommon, so it’s always helpful for members to hear how these mattresses age in real-world use.
Sorry to hear about the support foam, though. The cupping in the sleeping positions combined with the ridge down the middle is an interesting wear pattern.
A center ridge often develops because the areas under the sleepers compress and soften over time while the middle section of the mattress receives very little weight. Since no one typically sleeps in the center, that portion doesn’t experience the same level of compression and remains closer to its original height. As the sleeping areas gradually lose support, the untouched center can begin to feel like it’s “rising,” when in reality it’s the surrounding areas that have settled.
The support system underneath the mattress can also play a role. If your king mattress has been sitting on two Twin XL foundations, where those two foundations meet creates a double-width support line running down the center of the bed. That area is typically firmer than the rest of the support surface, so the center of the mattress may compress less than the sleeping areas on either side. Combined with the fact that very few people actually sleep in the middle of the bed, it’s not uncommon for a center ridge to become more noticeable over time.
Did you ever try rotating the mattress 90 degrees? After 7.5 years it’s probably a bit late for any rotation strategy to make a meaningful difference, but members who catch a center ridge earlier have sometimes found that sleeping across the mattress for a period of time helps redistribute wear and reduce the contrast between the center and the sleeping positions.
Since you’re moving to a split-king latex component build, I’d also pay close attention to the support system you’ll be using. If your split king consists of two Twin XL mattresses, they’ll generally perform best when each has its own well-supported foundation or on a king platform that provides uniform support across both sides. A flat, rigid, and properly supported foundation will help maximize the longevity and performance of your new mattress.
Thanks again for taking the time to share your experience. Long-term durability reports like yours are a valuable resource for the community, and I hope your new latex build serves you well for many years to come.
Maverick