I'm about 280 lbs and have a queen mattress that is maybe 4 years old. For the last couple months it feels like the whole thing slopes down toward the wall on my side. I've moved it around, flipped it once (it's not supposed to be flipped but I did), and it's still there. I don't see any cracks in the box spring but I also don't know what I'm looking for. Has anyone dealt with this? Is it the mattress, the box spring, or my floor?
Mattresses
Why does my mattress feel like it's tilting toward the wall
Could be the box spring honestly. You said you don't see cracks but the wood slats inside can sag without visibly snapping. Get someone to look under the bed while you lie down on that side.
This happened to me and it was the foundation, not the mattress. The slats had bowed. I replaced the box spring and it stopped feeling lopsided.
Four years is not that old for a mattress but for a heavier person it can be near the end depending on the quality. What brand is it?
It's some store brand, I dont remember the exact model. I think it was relatively cheap. I didn't think about checking the box spring while lying on it, that's a good idea.
Also check if the bed frame itself is level. Put a level on the rails and on the floor near the wall. Sometimes the floor slopes And you only notice it after the mattress starts breaking in.
If you flipped a mattress that isn't meant to be flipped, that can mess with the support layers and make one side feell lower. It might be that the damage is already done now.
Yeah flipping a no-flip mattress is risky. The foam on the bottom isn't designed to bear weight. But I'd still check the foundation first since that's cheaper to replace.
I weigh around 300 and I had the same tilt. Turned out my frame had a bent center support leg that was pushing the box spring up on one side. Worth crawling under there with a flashlight.
Cheap store bran plus 4 years plus heavier weight, it's probably compressed where you sleep. The tilt feeling is often just a big dip you're reading as a slope. Does it feel softer in the middle of your side too?
I'll check the frame and get someone to watch the box spring. It does feel a little softer in one spot now that you mention it. I don't want to buy a new mattress if it's just the foundation though.
If it is the mattress and you end up replacing it, look for something with a higher density foam or a firm innerspring. That's what held up better for me.
Get a cheap level from a hardware store before you buy anything. Might save you a few hundred dollars tbh.
One more thing, check if the box spring is the right size for the frame. Mine was a little too small and kept shifting so one edge was Taking all the weight. Just a thought.