I wish to insulate an unheated garage, primarily to limit summer heat, in the Sacramento, CA area. I'd like to put fiberglass batts between the roof rafters and wall studs and drywall over the bottom eight feet on the walls, leaving the inside of the gables and rafters uncovered. I know the vapor barrier goes toward the warm side in winter but in this area we get some sunny days. So some days the roof and walls are warmer outside than inside and on other days it's opposite. My question, if anyone knows, is which way does the vapor barrier face or do I even need to be concerned about it. It's generally quite dry here but can get very foggy in the winter.
Thanks for your help.