Max writes from Fairport, New York: "I am building a cabin in Dansville, NY and have been told I need R-38 in my cathedral ceiling to meet code. The building inspector told me this would require using 2x12 rafters. Is this true? Seems to me that's a lot of lumber to use."

Answer: Yes, you need to use 2 x 12 rafters. Or, you can use the lumber that would meet structural requirements and then furr them out to get the 2 x 12 space you need to accommodate R-38 insulation.