Insulating a pole barn question(s)
I have a 24’x34’ pole barn that I want to insulate so I can add some intermittent heat while working out there. I live in Iowa. In the winter, we park our cars in the front and my wood shop is in the back. There is a ridge vent along the entire ridge (34’). No soffit vents or gable vents. I do not want to add a ceiling. This isn’t our forever home and only need it insulated enough to trap some heat in while working out there – maybe 3-4 times per month, for a couple hours at a time, during the winter months. I can’t justify the cost of spray foam (So please no advice on spray foam). The pole barn is a wood frame, poles are 6’ on center, and steel on roof and walls. No house wrap between wood and steel.
I was going to start with the roof, since that’s where most of the heat will escape, and plan to insulate the walls later. Here’s my plan….
I was going to start by putting R-13 unfaced rolls of fiberglass insulation between the purlins, right up against the steel. I got a really good deal on some 1.5” ISO foil faced foam sheets (R10). Planned on nailing those to the purlins over top of the insulation. (So from outside in – steel, R13 between purlins, foam sheets). The foil face should act as a vapor barrier. Was going to tape the seams between the sheets and the seam between the foam and top chord of the trusses.
Any potential problems with this plan? Should I be doing it differently? Do I need an air gap between insulation and steel? Trying to avoid condensation – however is condensation even an issue since I won’t be heating it very often? Thanks!