Outdoor carpet on concrete sun room

Sun room is fully enclosed and the concrete floor of it is a bit lower than the rest of the house. The floor can get a bit damp, I live in an area with a very high water table and lots of houses have pumps etc...I'm working on improving the drainage but I know this floor will occasionally get damp. Previous owner put outdoor, astroturf like carpet which my dog liked to pee on when he was a puppy, ugh, so I need to replace it. That carpet is just laid on top of the concrete so it will be easy to remove.
What is the best way to install a new outdoor carpet here? Should I put some kind of vapor barrier down first? Any other tips?
Thanks