Incorporating a defense safety necessity allows a lot more strategies to get rejected above trivial needs. My 2 cents is exactly where the duct is uncovered it is needed to be 26 gauge. If it is roofed with sheetrock it doesn't matter what it really is made from it is https://gunnerqwcjo.ampedpages.com/a-simple-key-for-garage-attic-lift-storage-unveiled-61710073