If you have sealed the ceiling from the attic and have enough insulation up there You can consider it unconditioned space and storing some tyvac up there should not hurt anything but i doubt there is a problem that tyvac will fix.My problem with articles like it is that it talks a lot about the walls which is a different install from attic insulation installs. It's all about how vapor may travel but attic is different from air sealing the walls. I know that if I left the face paper on top it can trap the moisture in the air and condense into water, but air flowing over the insulation seems to be a problem too. It's like we're giving up on attic air problem because drying out is more important?
I still have to add some insulation in my attic. How about if I added unfaced insulation and loosely cover the insulation with something like tyvek? Would tyvek allow drying out? I'm not looking for the absolutes, btw.:smile: I also plan to run the attic vent fan which increases the air movement.