You are in Pittsburgh. You have to find what the level of the frost zone is. Down south here you only need to go down 12 inches to pour your concrete.
Up in Minnesota it is more like 5 feet, or more.
Y'all boys with 40 year old PT posts that are buried: Those were the good old days. They put arsenic in PT wood back then. About 15 years ago they removed the arsenic from PT wood, and today's PT wood won't last nearly as long, if it is under ground.
