Kermit writes again from Kansas City, Kansas: "There is a small portion of the attic that is used as a utility raceway. My HACV is also run through this space and although it is Owens Corning Thermal duct I would like to shelter it from extreme temperatures. This space also carries water line and is used for storage. I will probably have to cove the Kraft insulation with Gypsum but I would rather use a lighter material. You mentioned a 15 minute barrier; I thought it was 10 minutes and 1/4" to 3/8" would work?"

Answer: Your local building inspector should know for sure what the fire barrier requirements are in your area but I am confident the code requires a 15-minute barrier. I do not know if 1/4" or 3/8" drywall qualifies. They might. In most cases, 1/2" drywall is good for a half-hour rating so the thinner product may still be fine. If you have additional questions, I suggest you contact Lee Burlingame directly at 419-248-7149 or lee.burlingame@owenscorning.