Since my column on vapor barriers first appeared, I’ve gotten more reader questions on this topic than on any other that I can remember. I’ve had the opportunity to talk with several experts in the field as well, and here are some questions and answers that might help clear up a few more issues about this important subject:

Q: I just purchased a house a few months ago and installed R-19 batt insulation in the attic (with paper facing up). I realized afterwards this was not ideal, but to save cost I left it as is. The house is shaded by lots of trees and is still very cold so I’d like to add a second layer of insulation to the attic, perhaps another unfaced R-19. I read in your comments that the insulation paper has to face down when installing batt insulation.

What should I do with the existing insulation? To allow the air to flow, can I just make incisions on the paper on the first batt, or can I remove the paper from the first batt? Or do I have to reverse the first batt such that the paper is facing the inside of the house?

Can I use unfaced R-19 as a second layer of insulation, or are there better choices? I am trying to save cost. –Diana N.