radio63
Member
Been lurking here a while and this is my first post. I have a new 20x30 garage completed earlier this year. It was a pre-fab Tuff-Shed product. I'm still slowly fitting it out. It has a second story on it, due to a 12/12 pitched roof, attic trusses, and a sub floor that was installed at time of construction. It came with OSB roof sheeting with integral radiant barrier. I am planning on using the upstairs for storage and had hoped to do some light work up there as well. I was interested in insulating the second floor area by applying insulation under the roof sheeting and was looking at Roxul Mineral Wool, although fiberglass was still an option. I had an insulation contractor come out to give an estimate on insulating, and they said it was not possible because of the radiant barrier. The radiant barrier could develop moisture if the insulation was in contact with it, as well as rendering the blocking of the radiated heat useless due to conduction. I understand that the radiant barrier is beneficial, but it still gets very hot up there. My question is has anyone else encountered this situation, and come up with any remedies? Also, would putting in some spacing between the radiant barrier and the insulation help with condensation issues? I'm in El Cajon, CA where it gets plenty hot in summer. Thanks!