Yes, there is poly under the floor, and insulation too. It's been dry as a bone, we don't get any water coming up (the house is on the top of a hill). The only moisture we get on the floor is condensation if I leave the doors open during a hot summer day.
I've convinced my finance department (aka wife) to allocate a recent budgetary surplus (aka tax return) to improving our flooring in our Garage and Basement. I'm educating myself on the different options, which has led me here. I am sure there's lots to learn in the existing discussion so I've...