They are stronger than they look. keep in mind that all joints in a lack have no cross brace so the leg-surface joint is actually pretty strong. The big thing

They are stronger than they look. keep in mind that all joints in a lack have no cross brace so the leg-surface joint is actually pretty strong. The big thing is that a tight install of the legs and adding tension and mounting the hardware helps cross re-enforce them. The examples where people use a second lack top as the bottom are WAY more reenforced than one would expect, you probably could use it as a chair.