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”?
Remove the load, square it up, and attach 2x4s like this on both sides. It will help a lot and you won’t lose any used space.
Bonus points if you fasten it to both horizontal struts.