Insulating non-wrapped structure

[Wild Turkey]

Spray foam then OSB as mentioned is what I used in my new shop and I like it so far. I'd suggest a gloss latex paint sprayed on the OSB to fill some of the surface roughness that will hold dust. My BIL used sprayed on cellulose in his shop and the dust problem is huge. So far I've had no problem with the foam on my ceiling.

What you really want to control is humidity. Not just to protect tools from rust but wood moves as it changes moisture levels and can cause some real headaches. Spray foam will do a lot to help.

I put several big windows in my shop. They take up wall space that could hold shelving, but I love the natural light.

[Tim in Indiana]

They do have a liquid, spray applied air & vapor barrier that can be applied to the interior. A coating is sprayed into the stud bays from floor to ceiling. There are also roll-on coatings that will do the same thing, just a bit more work to apply.

If you want it more airtight, you can then apply it with the building under positive pressure. This is done with a blower door which pressurizes the building causing air to leak at any openings or cracks. The building is setup with a spray system that looks like sprinklers, but they produce a very fine mist which is carried on the air to the remaining openings.

You can really tighten up a building this way. 

And the OSB wall covering is a good suggestion. I have done this a couple times. Pick the smooth side of the panel, prime it first with an oil-based primer to avoid blistering or raising the wood flakes.  Then roll or spray on a coat or two of a good gloss or semi-gloss paint. You'll be surprised how well it covers doing it this way.

[MKepke]

Y'all are gonna make a 'two story barn/shed' air infiltration proof by spray foaming the walls? <insert raised eyebrow>

Unless the OP plans for weatherproof barn doors and windows and addresses that bare concrete slab wicking moisture up, that seems not very cost-effective.

Foil faced fiberglass insulation..check local codes for whether the barrier should be inside or outside..and call it a day.

Put a radiant barrier in the roof and insulate with foil batts. Remember to allow air movement under the roof deck. Bare barn/shed may not have any provision for roof ventilation..

Spend the $bajjillion dollars you save on a decent AC unit.

-Mark

[jppierson]

Thanks all for your advice. The barn/shed isn't a real barn, there are a set of french doors on the west side, and a man door on the north, windows on the north and south on both stories. I am not following what I could do about the concrete slab wicking moisture except to but a vapor barrier down and install finish flooring. I intend on leaving the floor as is and use horse mats (cheap at Tractor Supply) where my workbench will be for cushioning my feet. The floor was previously painted battleship grey and is of course peeling due to water infiltration around the perimeter. It going to be a shop so I am not too concerned about that particular cosmetic. I have some work to do on the trim around the entire structure before insulating. There is a 2x2 or so wood trim at the bottom of the t-11 on the exterior that wraps around the base of the building. These are basically all rotted out, so I intend on replacing and using a Z (?) shaped metal flashing that would tuck up behind the T-11 and over the new trim. Currently, I can see light at the bottom of the T-11 where it meets the base plate in some places, so first things first to at least make the structure weather tight. When I had the roof replaced last year a ridge vent was installed. I have a call in to a local gutter company to install gutters along the length of the building to resolve the water splash when it rains.