Charles writes from Wisconsin Rapids, Wisconsin: "How can I insulate the floor and roof of a sun room with only 6" of access below and no attic. There is about 4" between the roof rafters accessible from a ridge vent."

Answer: What you describe is a very complex and difficult application. The answer with all of the possible variables is too much for my furry paws to type. Please call the nice people in the Owens Corning customer service department to discuss your situation. Their number is 1 800-438-7465.