This paper will summarize the results of ice impact tests that have been conducted by the author's firm on built-up roofs. Ice stones of various sizes were propelled at various roof samples employing a special launcher. We found that the built-up roof samples resisted being damaged by icestones up to two inches in diameter. Damage appeared as a "donut-shaped" crater in the roof where the gravel and asphalt surfacing were removed and the roofing felts were ruptured. In no instance was the gravel driven downward into the roofing felts.