I agree with Ron. I belive Tyvek is simply a barrier to stop wind with little or no R value. I have cellulose insulation in my home & it is a better insulation than fiberglass that is in the older part of my home. I hired a professional to install my cellulose and it was not much more money than doing it myself. The competition around here is pretty decent so it is easy to find a contractor with better equipment than Lowe's to install the cellulose.