We had a metal pole barn built. After the barn was framed, single bubble foil insulation was installed around the entire frame and then the metal was installed on top of the foil insulation. We are finishing the interior of the building (concrete floor, electric, heat/ac). We have finished framing with 2×4’s and now plan on insulating and finishing off the interior. We live in the Midwest. We plan to use 3 1/2″ batt insulation in the framing (that will leave several inches between the bubble foil and the fiberglass) and then finish off with drywall. We are also drywalling the ceiling. We do not have any vents in the building (30×60) so we plan to put one gable vent on each end to allow the barn to breathe. We may want to put some loose insulation in the attic. Does it sound like we are doing everything correctly? Any suggestions?
My only concern from your described application is that you have a vapor barrier on the wrong side of the wall and roof. I don’t know what you will be using the building for, but if there is a chance that moisture created inside was sufficient, it could get trapped in the mass and have nowhere to go. Your gable vent might have some mitigating effect, but you should consider putting another vapor barrier on the inside of the wall, behind the drywall. Other than that, it sounds like you’re doing a fine job.