Asphalt shingles are rated for impact resistance with class 4 having the highest resistance. What class has the lowest?

Asphalt shingles are evaluated for impact resistance by using a classification system where Class 1 indicates the lowest resistance to impact among the available classifications. This means that Class 1 shingles are more susceptible to damage from hail and other forms of impact compared to shingles rated in higher classes.

The classifications range from Class 1 through Class 4, with Class 4 providing the highest level of protection against impact. Thus, the significance of Class 1 as the lowest rating is that it serves as a benchmark for the minimum acceptable level of impact resistance in roofing materials. Home inspectors should be aware of these classifications as they influence the suitability and longevity of roofing materials in various weather conditions.