we have the old insulation in our attic from 1983. it looks like cotton. we put in some rolls about 5 years ago of the pink panther stuff. the salesman told my husband to put it between the joists. unfortunately, my husband put it over the rafters. i didn't think it sounded right but he insisted. i see now by the video this was wrong. i am going to buy some more (we need it)and put it in right and rearrange what is in there. my question is, can i put plywood on top of it to use it for storage? i know what it said about air circulation near the joists. i mean right up inside of the attic. about 2 feet. we are in nc, the south.