The home that we recently moved into (Peninsula, OH 44262) has a good sized detachted garage/barn. 40' wide, 36' deep in one bay and 39' deep in the other. From the concrete floor to the bottom of the truss is 11.5'. I am thinking of adding insulation to allow for winter shop use. Current thoughts: Apply 1/2" OSB to the bottom of the truss (which are 24" on center) and blow in cellulose as we did in our attic. For the walls, I was considering sheathing with either OSB or plywood (T1-11 perhaps) on the inside of the 6"X6" poles and dense pack the cavity with cellulose. Because of how the structure is strapped with 2X6, I would have 7" of space for insulation. The garage has vinyl siding, house wrap, and OSB sheathing. Looking for comments on specific details. (do I want ploy vapor barrier on the inside? Should I have some rigid foam in contact with the cement to eliminate any wicking into the cellulose?) Thanks in advance. Ian.

I'd start by figuring out how many hours per year you are going to use it so you can get a rough idea of payback.

In my own "pole barn", now shop and office, I started with Thermax on the outside followed by blown glass then drywall for the office and shop wall. I went 4 feet up with OSB and 5/8 rock for the walls in the garage with 5/8" rock for all ceilings with R-50 cellulose over all for sound.

The 1/2" Thermax under the roof rafters eliminated the solar load. 2400 sq.ft. 10 ft ceilings in Minneapolis; less than 2 tons of air and 30 mbtuh heating.

In my own "pole barn", now shop and office, I started with Thermax on the outside followed by blown glass then drywall for the office and shop wall. I went 4 feet up with OSB and 5/8 rock for the walls in the garage with 5/8" rock for all ceilings with R-50 cellulose over all for sound.

The 1/2" Thermax under the roof rafters eliminated the solar load. 2400 sq.ft. 10 ft ceilings in Minneapolis; less than 2 tons of air and 30 mbtuh heating.

Jon - I understand where you are coming from, but right now in the winter, the space is not usable. I have some longer term projects ahead of me and taking advantage of the winter would be worthwhile. Not sure the payback would ever be positive for something that is unnecessary as this.

Badger - I will have to look at Thermax. Doubt I can take advantage of that since the building is already complete. I would not be looking at any air conditioning, but am looking at NG radiant tube heater.

The building might end up having better insulation than the house.

Ian.

With a large enough NG radiant heater, you can make it reasonably comfortable with no insulation. The numbers of heated hours will greatly effect the ROI of just doing that vs good insulation and air sealing.