Astm: C920

: How much a joint can expand or contract without the sealant failing.

: Defines the percentage of joint expansion or contraction a sealant can handle without failure. Class 100/50 : 100% expansion and 50% contraction. astm c920

ASTM C920 is more than a line item on a submittal; it is a performance contract. By understanding the classifications, architects and contractors can ensure they select a product that will not just fill a gap, but maintain the building envelope for years to come. : How much a joint can expand or