Kevin,

I would agree that adding a PT block between the sleeper and the concrete block would help with any moisture transfer. The hand hewn beams that I was referencing were White Oak, and I did not see any significant signs of moisture problems. The sill beams of this barn sat directly on a mortared cap of the fieldstone walls. I often find some rot or water damage on many of the barns that I restore. These were built before the advent of pressure treated lumber. You would obviously want your barns to last as long if not longer than those that I have worked on, so I would encourage you to take the appropriate steps to ensure the future of your barn, well after both you and I are gone. My Moto is "Building on the Past for the Future to Hold."

Rooster