John writes from Steele, Missouri: "I would like to blow some kind of insulation under my house. The house is so close to the ground no one can crawl under to put down vapor barrier. My under-house duct work is not insulated. The heated air is cool by the time it gets to the north end of the house. Is there some kind of special insulation I can use?"

Answer: While we have loosefill Fiberglas insulation that can be blown into a cavity, it is not generally used under a floor. I have two questions: How will the insulation be held in place? And, is it possible to install a vapor retarder?