Yeah you have the order right on installing, but I was getting mixed info... I think they said to use un-faced so I could pack as much insulation in as possible. (this seems strange to dense pack fiberglass since from all the reading I have done the air space in the insulation is what gives it an R value. I think the other thought was that you can get a better vapor barrier with the poly then faced bats stapled etc.
All that said, I happen to have a lot of kraft faced fiberglass bats so I might go that route. Tape really well then install sheetrock and seal it well also.
I was told that Bibs are the next best thing to spray foam...
Heck I called one pole barn company in our general area and the guy said to just put bats in and call it good (I did not trust this information) I personally think that Fiberglas in contact with the metal will wick and hold any moisture then the wood would start to rot, thus the use of the tyvek.
the original insulation that I pulled out and in the area that we tore out sheet rock it was just faced fiberglass insulation (Metal - Condensation blanket - 1" air gap, Faced fiberglass insulation in another framed wall - sheetrock - paint) Because the mice caused so much damage it is hard to tell if there was any issues caused by this method. I do know that the metal on the building is pretty tight when I ripped out the old Fiberglas/condensation blanket there where very few places that showed signs of wind/dirt intrusion from the siding overlaps...So I kinda question how much of a vapor barrier the metal siding is. We don't have closure strips or rat guard on the shop thus the mice found their way in and I wonder if it was done that way to let moisture out if it collected.
I think that for the most part no one knows what the right way is aside from spraying it.
If I was planning on living here for 20 years, I'd spray foam it from what I have read. I come across so many people that are happy with it and would do it again in a heart beat but its expensive!!!!!
I have learned that cellulose cant be in contact with metal if it gets wet it produces salt and then rusts
Lol I duno how much help I am

I overthink everything until I am more confused then when I started!