The size hail necessary to damage property was the subject of a recent NOAA task force committee meeting on re-evaluating the national severe thunderstorm warning criteria. The lead author served on this committee. The authors' firm conducted ice impact tests on common roofing and siding materials to determine threshold sizes needed to inflict damage. A device had been invented to launch solid ice stones at desired velocities. This paper will present the results of our ice impact tests along with the methodology utilized to conduct such tests.