I am about to receive 15 chicks from a local supplier, they are all supposed to sexed and between 1 to 3 weeks old. They are arriving slightly sooner than I was expecting, as I'm still waiting on parts to construct the permanent coop. It could still be 3 to 4 weeks before the coop is ready for them. I built a cheapo brooder in my garage for them, as I don't plan to raise chicks regularly a more permanent brooder seemed like a waste. The problem is, the walls on the brooder are only 11 inches high, 9 inches if you subtract the two inches of pine shavings I have on the floor (Is that too much? seems very deep for little chicks) They will be unmonitored during the day when the wife and I are off working, and I have great concerns that they could be up to 7 weeks old in there before the coop is ready, and my little 11 inch walls are not going to contain them and I'll be chasing little chickens all over the garage, or worse they will get out in the morning and have no access to food or water the entire day unless they can get back in. Are my concerns valid? What would you experts suggest?