Ed, I did not make it clear but the reason I asked whether it was a mistake to use the 3/4 inch pressure treated plywood above the plastic is that I already have the plywood. I can't return it. Do you know if there will be problems if I use it? Just how bad is it if I put the plastic above the plywood sub-floor and below the plywood floor?

Ed and Rob, I will check into what types of housewrap are available here starting with Tyvek (which I have never heard of). I am definitely going to put something solid at the bottom of the joists.

Rob, I am planning to put 1/2" plywood over the 3/4" plywood sub-floor and I going to place it so that the joints are in different places.

Gary, I will see if I can find fabric of the type you mention.

Andy, I am relieved to hear from you that "you do not require air movement under a floor like you do in an attic where there is drastic temp changes". That is what I suspected but it is good the hear it from someone else.

Andy, I spoke to the inspector assigned to my building and he did not seem to know much (in fact, he did not seem to know anything) about floor insulation under open spaces. Everything I suggested he seemed to go along with and say that I should try it and see how it works out.

Rob, thanks for letting me know about the DC schematics. I hope that you are not just doing the symbols for me and that you will be able to use them elsewhere. I really really appreciate the electrical advise that you have given to me.