That's why building code requires pressure treated wood at any place it's to come in contact with the ground of concrete in most (all?) places pressure treated

That's why building code requires pressure treated wood at any place it's to come in contact with the ground of concrete in most (all?) places pressure treated (if I'm remembering my high-school drafting class correctly). That's why concrete piers you can buy generally have a pressure treated wood cap they come with, and why the posts used on top of them under a house to hold the floor joists are also generally pressure treated.