Fire resistance is an important attribute of any loose-fill insulation. Current requirements only test these characteristics prior to installation in the house. The effects of aging on these characteristics have just recently been investigated. This paper reports the results of fire resistance testing on loose-fill insulation samples that have been installed in attics for a minimum of two years. Cellulose, fiberglass and rockwool insulations were sampled from attics in different areas of the country. Smoldering combustion and critical radiant flux testing were performed on all samples. Results are presented and compared to similar published papers in vestigating the effects of aging on loose-fill insulation.