ASTM C920 is the standard specification for elastomeric joint sealants. The "Class" rating specifically defines . What Does the Class Rating Mean?
Movement Capabilities and Selection Criteria for Elastomeric Joint Sealants Standard Reference: ASTM C920 – Standard Specification for Elastomeric Joint Sealants astm c920 class 25 vs class 50
An engineer calculates that a specific building joint will expand and contract by a total of 0.4 inches due to thermal changes. ASTM C920 is the standard specification for elastomeric
Superior "recovery" (the ability to return to original shape). These are essential for metal buildings, as metal expands and contracts significantly more than concrete or wood. astm c920 class 25 vs class 50