I just move to Florida from Massachusetts. The house has 3 inches of rock wool in the attic. There is no insulation over the garage space which is part of the house. Two of the garage cinder block walls are adjacent to the house making up two interior walls. One of those walls has a door to enter the house. Knowing I needed more insulation in the attic, I took advantage of Tampa Electric’s energy aduit. The energy analyst agreed that the attic needed additional insulation, and they provide you with a coupon to help defray the cost. Where we differed in opinion is that I said that the space above the garage should be insulated too. He countered and said no. His logic is that since it is not a “conditioned space” I should not insulate the garage ceiling, any heat build up in the garage needs a place to go and if I insulated the garage ceiling it would be hotter inside the garage.

My thinking is that the attic space will get much hotter than the ground, and the attic heat would reradiate into the garage space. There is a gable end fan that comes on when attic temps reach 100 degrees. Is there that much heat from the ground in a subtropic climate zone? The garage door faces due south and it gets warm. Should I insulate the garage door? Does any one have any experience with this situation? The energy analyst said my logic only applies to colder climates.

Looking for help,
Joe