Hello DIY'ers quick question i could use some help with, I Live in California my home is a 1 story home, im remodeling the home, when i removed the ceiling drywall there is no vapot barrior between the insulation and the drywall. Im replacing the insuraltion with R-30 Bats Unfaced. Once finish the whole home im going to put blow in insulation over that. Do i need to install a Vapor Barrior between my drywall and bats insulation. My Attic has good ventalation, ive installed a few attic fans previously.