Floor Over Moist Basement Concrete

[MNP]

External foundation work has been done around my 1906 house to
eliminate the rivers in the basement after rains. But the concrete
floor is still gets moist in lots of places. The contractor wants to put
pressure treated 2x4s down with pressure treated plywood on top, and
then ceramic tile.

That sounds good to me...but will the moisture under the plywood create
serious problems like a potentially dangerous mold problem under the
floor.

Any comments on this approach would be apprectiated.

[Concretemasonry]

It sounds like a vapor barrier between the PT 2x4s and the plywood.

I just attended a class on mold and found out that some types of molds do grow very well on some types of PT wood.

I don't know what the books say, but a vapor barrier certainly can't hurt if air can circulate between the 2x4s and under the vapor barrier.

Dick