A friend of mine just finished the restoration/relocation of an old barn and he replaced the entire floor system with oak. Red oak for the joists, which were peeled logs with one sawn face, and white oak for the sills. The foundation is condrete wall with feildstone veneer on both sides, about two feet thick. The white oak sills rest directly on the foundation. The restoration was done by highly reputable company. I have seen the old PT rot away that was only five to ten years old. I have noticed that the "new" PT has a no ground contact warning on the label now. That kind of defeats the purpose of using it for the sills if you ask me. Hopefully someone with more PT experience will be able to post.
Dave
