Just found out a moving box can hold 65 pounds, so why did mine fold at 30?
I was reading the fine print on a U-Haul box at my parents' place in Rochester last weekend and it says 65 lb capacity for the medium size. Mine buckled carrying maybe 30 pounds of books and I had to double it up with a second box for bottom support. I'm wondering if the tape job was the real problem, or if I'm just stacking wrong, like heavy on top instead of bottom. What's your go to trick for reinforcing the base on a heavy box?
Did you tape the bottom seam or just the top? That bottom seam is the one that actually blows out, and one strip down the middle won't cut it, you need tape running along the seam and then a strip going up the sides. Also the 65 lb rating assumes the weight is spread out, so 30 pounds of books in one tight pile puts way more stress on one spot than the box was tested for.