Gypsum board

Abstract

Described herein is a composite board and a method of producing a composite board, the board having increased fire endurance. The board comprises a sheet having a thickness greater than about 0.014 inches, and a thermal conductivity of about 0.1 w/(m.k.) or less. The composite board can be part of a wall assembly comprising two boards defining an interior cavity, the sheet facing the interior cavity.

1 - 23 . (canceled) 
     
     
         24 . A composite gypsum board comprising:
 a core comprising set gypsum formed from at least water and stucco, the core having a substantially flat shape and a generally uniform thickness, the core defining first and second board faces in opposing relation;   a sheet disposed in bonding relation along the first board face, the sheet made of a material that has a thickness greater than about 0.017 inches, possesses a thermal conductivity that is less than about 0.1 w/(m.k.), and is applied to a back side of the composite gypsum board; and   the composite gypsum board having a dry weight of less than about 1750 lbs/1000 ft 2  when at a thickness of about ⅝inch.