Input on how I am considering insulating a detached 1940's garage
We are looking to buy a new home that has a detached 24x32 garage that we believe was built in 1940. We are in zone 5A. The interior walls are cinderblock, the siding is vinyl, I have not had a chance to look behind the siding, but I assume probably minimal sheathing / no vapor barrier.
I want to insulate this space and add a heat pump so I can use it as a workshop, which includes wall storage for lumber which requires studs to mount to (at least where I put lumber).
From my research I think it makes the most sense to insulate in. I am playing with the idea of adding 2" of foam with taped joints (with tyvek housewrap tape?) glued directly to the block walls and furring strips.
I am also playing with using a thinner layer (~0.5") of foam (still glued and taped) and then doing a 2x4 wall with faced (to the inside) fiberglass insulation. I can't tell if this will prevent moisture from traveling into the fiberglass or merely trap it once there?
Looking for thoughts and idea's for a simple way to make the space usable that won't cause more issues. Thank you!