When I built this rack, it was perfectly square, the saddles were all tight, and it didn’t move at all. 3 months later, I guess the pressure-treated wood has shrunk and it’s sagging.
So what’s the right way to build something like this? Just let the lumber sit for several months to dry out? Don’t buy from Home Depot? Is there a way to tell when the wood is “ready”?
I don’t think wood shrinking/movement is to blame here at all. With single attachment at each joint and no bracing, there’s nothing stopping the whole thing from “racking” e.i. going from a rectangle to a parallelogram. You need diagonal bracing.