This topic includes information related to cast roof decks installed during construction. Cast roof decks are roof deck substrate systems that provide structural support to roofing materials and anticipated loads. Common types of cast roof decks include gypsum concrete and cementitious wood fiber roof decking. Gypsum concrete roof deck systems are assemblies of form boards, purlins, wire mesh and gypsum concrete. Cementitious wood fiber decking systems are tongue and groove panels.