I built one too, but getting birds out is difficult. Had a sick bird and crawling through poop and stuff to get to it....nasty. Moving them to a hoop house and using this as a puppy playpen instead.
I just got a trampoline for this very purpose (to the kids' disgust)! I'm planning to use it as a day pen for young birds....the predators seem to leave my adult birds alone, but the youngsters, not so much. Hubby picks it up this evening. Got it free from a family nearby.