Boyd writes from Massapequa Park, New York: "I have a house built in 1958 with 2x6, 16" on center, ceiling joist with about 3 1/2" of kraft fiberglass insulation. I want to add more loosefill insulation to give me R49 for my area in NY. I also want to put in a raised floor in the middle of the attic to add some storage space above this, so that I will not compress and loose the R-value and want to give enough clearance and airflow. How much insulation needs to be added to get me this R-value??"

Answer: Although you reported the thickness of your existing insulation, I don't really know its R-value. Owens Corning, for example, manufactures three R values at 3-1/2" (R-11, R-13 and R-15). If you have the minimum, you need an addition R-38 in most areas of the country, according to U.S. Department of Energy recommendations. This would be 15-1/2" of our blown-in Advanced ThemaCube Plus® insulation.