I am remodeling a bathroom in a house in New Mexico. I have to replace some of the walls including the framing which sit directly on the concrete foundation. I know in a lot of areas of the country it is recommended to use pressure treated lumber and/or a moisture barrier membrane between the stud and the concrete. In the construction in this area, I do not think I have ever seen a barrier placed between the concrete foundation and the framing. It may not be necessary because this is a dry area, but better to be safe.
I would like to know what kind of barrier should I use between the concrete and the stud. I have 5 mil plastic I was going to lay down and then use concrete screws to attach regular studs to the concrete (not going to use pressure treated studs). I did not see any signs of moisture damage on the old studs I took up from the concrete, so I assume using untreated studs with the plastic would be that much better than what was there before. Any other suggestions that may work better?