Insulation of Pole Barn

[MiGarage]

Happy Easter, I am embarking on insulating my 40x60x14 Pole Building/Hobby Building. I have settled on using Rockwool R23 comfort batts for ease of cutting, install and rigidity. Unfortunately the barn was not house wrapped prior to steel going on. Do I need to something up or retro house wrap between the poles before installing the Rockwool or can it be placed up against the gifts and bare steel? I have seen varying opinions. Rockwool didn’t have a suggestion as they say it’s not specifically made for insulating pole buildings. I plan to hang plastic as a vapor barrier on inside and sheet with OSB. Picture of installed is from RR buildings YouTube and how I plan on installing. Any help is appreciated.

 

[MiGarage]

Forgot to mention I am in Southern Michigan

 

[ericm]

When I had my building done they would have built it without wrap but with insulation. I wanted wrap to keep the wind out.
But the insulation they used was giant fiberglass batts, with nails driven part way into the girts to keep them from sagging. Rockwool should be better at keeping wind out.

In the west coast areas I'm familiar with the wrap goes on the outside only. I don't know about putting it on both sides.

 

[jack stand]

I think the Rockwood is too dense to let the air that might leak in from the metal. Anyone who's ever opened a closed wall can see that without air sealing, fg insulation is basically an air filter
first, and what heat (or cooling) doesn't blow out is the insulating (second) portion of its effectiveness.
A good housewrap would have been beneficial for your building, but not to the same extent as one using fg.

 

[MrFuso]

OP, how did things end up going? I don't think you need a vapor barrier with Rockwool. I'm using the same thing for my new shop, just trying to figure out wall covering now... Would like to know what you're going to do.

 

[deadmanx]

Also wondering how this went? We are also considering rockwool. Second to that about vapor barrier with rockwool, I don't think it's needed. My barn has housewrap so I hope that is an added benefit on top of the rw.