I know now that I should have put a vapor barrier in the ceiling when I redid it a couple years ago, but hindsight is always 20/20. That is what happens when you ask the question to the wrong people. Now I have the dilemma of frost buildup on the roof decking when it gets below zero. What are some of my options? Will a couple coats of oil based paint help retard this, or that vapor primer I have read about help. Should I blow in some more fiberglass insulation or cellulose? How about laying some unfaced R19 on top? What is the best route to take. I spent a lot of time making a race track ceiling and do not want to redo it.