Anisur Rahman Zuall

Gypsum is approximately 21 percent by weight chemically combined water which greatly contributes to its effectiveness as a fire resistive barrier. When gypsum drywall is exposed to fire, the water is slowly released as steam, effectively retarding heat transmission. Fire rated gypsum drywall is more fire resistant because it contains glass fiber reinforcement and other additives within its specially formulated gypsum core to help it hold up longer to a fire exposure. Fire  rated drywall is referred to as “Type X” and must be third-party certified by an independent testing and listing agency such as UL (Underwriters Laboratories Inc.) and ULC (Underwriters’ Laboratories of Canada) to meet the fire performance requirements prescribed in the ASTM C1396 (CAN/CSA-A82.27) Standard Specification for Gypsum Board. Types of Fire Rated Gypsum: Type X fire rated gypsum drywall that is 5/8 -inch (15.9mm) thick and installed on each side of nominal 2-inch x 4-inch (38x89mm) wood