For new ways to update this look,
see http://www.hometalk.com/28485487/how-to-take-a-simple-bench-to-a-whole-new-level
OKAY!!!! The lumber dept guys at Home Depot took the time to analyze my bench and give me their opinions of how sturdy it is and how much weight it will support. The following is how I interpreted their analysis. They said up / down weight is not the issue. The stair treads on top of the wood crates supported like my picture would hold a great deal of weight. Possibly, even as much as 800 lbs to 900 lbs. Stair treads are specifically made to withstand a great deal of weight. They told me the boards are not going to break. The weakest part of this bench is when there is side to side movement aka horsin’ around. Two adults scooting back and forth side to side is when it would be at its weakest point. To make this super strong, they suggested lag bolts for a secure hold.