Garage Ceiling Insulation/vapor barrier Question: Should I insulate between the floors and do I use a vapor barrier? Iâ€™m a homeowner not a contractor seeking some advice/opinions. I have 1 Â½ story,over sized 2 car garage. The garage itself has 11-Â½ foot ceiling. The second floor is accessed by a full set of stair within the garage. The garage I will be finishing soon, the second floor is a long way off, 5-10 years maybe never. I will be heating the garage a max of 20 days during the winter via a gas heater. A 6-mil poly is under the concrete slab. There are times I have noticed, on days when it warming up much fast outside, and colder inside, moisture is high in the garage. I have already installed R38 with a paper barrier facing down between the floors. Before I have it sheet rock, was this a mistake? If so, do I need to remove the paper completely or just punch a lot of holes it? Thanks in advance.