If the mattress is only five years old, it is more than likely a one-sided product using some sort of a minimal flex foundation, so flipping the mattress and adding plywood underneath it unfortunately probably won't be viable options. The frequent rotation from head to foot is a good suggestion. Most innerspring brands allow up to 1.5" of body impression until the item is considered defective. If the measurements were very close to that tolerance, and you've exhausted your options with your local retailer, consider contacting the licensee that produced the mattress and politely state your case. Their name and address should be listed on the law tag sewn into the tape edge of the mattress. Perhaps there is an issue with the quality of the pillowtop construction with the inner flanges not being properly secured, allowing the foam to travel too much in the quilt. The licensee may allow for a one-time accommodation for you. It certainly doesn't hurt to ask. With that being said, if you do qualify for an accommodation, you may wish to avoid the brand with which you're having the bad luck, as many plush mattresses within the same product line will use the same foams found in the pillowtop version of the same mattress. Your retailer can provide that information for you. Good luck.

Hello,

If you can get the warranty approved, they will likely be able to offer a selection of replacements instead of just sending out the same exact mattress. In the mean time, if you haven't already, rotate the mattress around so new/different foam is being utilized while in use.

I don't like any of the above answers. Damn the fine print in useless 20 year warranties. That's what I say. Your not as screwed as you think. If you have some bowling balls or fire safes or an old anvil just put them onto the mattress for a week or so and don't remove them till the inspector rings the door bell again. Ask him politely to wait just a minute (while you scramble to shove all the weight into your closet) and let him measure it now!

I would try rotating from head to foot first and if that doesn't work, then I would flip the mattress over and sleep on the reverse side of the mattress. You can add blankets for comfort.

You could also try to put some Columbia brand, formaldehyde free plywood cut to the size you need from Home Depot, put that under the mattress to try and firm it up. Good luck, I hope one of these things works for him.

Flipping the mattress over is an option. But for comfort, add a 2" soft Latex Topper.