Todd writes from Caledonia, Michigan: "I have a bonus room (playroom) above the garage, and I would like to add another layer of insulation. Currently it has 3.5" of insulation between the studs. I would like to add another layer of unfaced (correct?) insulation going horizontally but how do I keep it from falling or to what do I attach it? I don't have much room to maneuver in the crawl space above the garage."

Answer: Unfaced fiberglass insulation is appropriate for this application. You can use nylon banding or metal insulation supports to hold it in place.