What is ASTM C 1396?
ASTM C 1396 is the new “Standard Specification for Gypsum Board.” Instead of having a different designation for each type of gypsum board as before, C 1396 is the Standard that includes Gypsum Sheathing, Water Resistant Gypsum Backing Board, Gypsum Soffit Board, and other types of gypsum board. For example, ASTM C 79 which was the Standard Specification for Gypsum Sheathing is now incorporated into ASTM C 1396.