What are the extreme temperatures?
Matt writes from Erie, Pennsylvania: “I am remodeling our home. My father in law is an Owens Corning preferred contractor. He wants to blow in your Atticat insulation. I have read articles & spoke with the cellulose green fiber people that state fiberglass loses its r factor under extreme cold or hot conditions. If this is true, what are the extreme temperatures?” Answer: Attached are a few documents that should be helpful in comparing fiberglass and cellulose insulation. The first is a document that addresses the claims and facts about both types of insulation. The second is a letter that addresses the specific question you asked about thermal performance. The third is a table referenced in the letter. Bottom line: The effect is minimal, but if this is truly a concern you should use batts, not loosefill and not cellulose. A few things have changed since the brochure was published. For one, the U.S. Department of Energy now recommends up to R-60 in many parts of the country. The weight
