What percentage of water is entraps in gypsum wall?

Gypsum board, commonly known as drywall, contains a significant amount of water that is chemically bound to the gypsum (calcium sulfate dihydrate) itself. The hydration process contributes to the overall structural integrity and fire-resistant properties of the material. Approximately 20% of the weight of gypsum board is attributed to the water contained within it. This remarkable percentage supports the notion that gypsum wallboard can help with moisture regulation in indoor environments, as the water can be released back into the air in low-humidity conditions or reabsorbed when humidity levels rise. Thus, understanding that gypsum contains around 20% inherent water is key in fields such as construction, fire safety, and material science.