I NOTICED SOME TIMES IF YOU STACK A BOX ON TOP OF ANOTHER BOX AND ONE BOX IS EXTREMLY HEAVY IT WILL CRUSH THE TOP OF THE BOX IT SITS ON OVER A PERIOD OF TIME. BUT THAT WOULD STAND TO REASON UNDER THOSE CIRCUMSTANCES.
I recently moved and these boxes were my very favorite. They are easy to assemble easy to carry easy to disassemble for reuse later on; I am very satisfied.