Originally Posted by
Walter Mooney
I have to agree with Mr. Wilson -- start by lowering the temp in the attic and separating it thermally from the garage. And IMHO, you can't beat radiant barrier materials for that. Google "foam insulation boards with radiant barrier" and you'll find a link to a Johns-Manville product. Buy a few sheets of that and apply them to the attic wall and maybe even to the underside of the roof rafters. Just make sure the radiant barrier side faces out or away from you. Measure the temp in the attic before you install it and the day after you install it. I'll bet you'll see at least a 20-degree drop in the temp in the attic.
My $0.02