Set Up: Simply take your mattress out of the box and enjoy watching it decompress; Jumping, walking, and sleeping on your mattress can speed up the process. 4″ Standard Mattress Topper. How long does it take for the mattress to fully expand after unboxing?.

Set Up: Simply take your mattress out of the box and enjoy watching it decompress; Jumping, walking, and sleeping on your mattress can speed up the process. 4″ Standard Mattress Topper. How long does it take for the mattress to fully expand after unboxing?.