Tim writes from Buffalo: "I have a 66-year-old house in Buffalo, NY with five inches of what I believe is vermiculite (dropped-in) insulation in the attic. The insulation is 5 inches deep and not densely-packed. It is between the joists in the ceiling of the 2nd floor and the covered floor of my unheated (and unused) attic (so the vermiculite insulation is currently completely covered by nailed down flooring). I want to upgrade and save on my natural gas bills. Can I simply lay batts of Pink (R-30) across the wood floor, or do I need to pull up the floor, and lay the Pink on top of the vermiculite? Would that cause any problems (such as moisture)? Or, should I pull up the floor, remove all the vermiculite, and lay new R-19 batts with vapor barrier between the joists and then lay batts of R-30 perpendicular on top of the new R-19 batts? Thanks for any help you can offer!"

Unfaced fiberglass can go over top of the vermiculite. It can also be placed directly on the floor in the attic. Provided your attic is properly ventilated and you have normal indoor relative humidity levels in the home, I don't expect you to have any moisture problems.