Abstract: Composite roofing structures can include mineral fiber roof cover boards with high concentration of mineral wool or mineral wool and perlite. The roofing structure may include: a roof cover board including a dried base mat including: 8-25% mineral wool, 40-65% perlite, 9-15% binder, 9-15% cellulosic fiber, and 0.25-2% sizing agent, all % by weight; an insulation layer; and a roofing membrane. The roof cover board is over the insulation layer, the roofing membrane is over the roof cover board. The roof cover board is attached to the insulation layer. The roofing membrane is attached to the roof cover board. Alternatively dried base mat may include: 30-70% mineral wool, 10-50% perlite, 5-15% binder, 2-20% cellulosic fiber, and 0.25-2% sizing agent. Alternatively the dried base mat may include: 60-90% mineral wool, 0-10% fiber, 0-10% perlite, 4-10% binder, 0-5% gypsum, and 0.25-2% sizing agent.

Abstract: A gypsum fiber roofing panel with an angled edge for accommodating environmentally-induced expansion is provided, including a homogeneous body formed from a slurry of gypsum and reinforcing fibers having a face panel, a back panel, and a plurality of side edges, each side edge having an angle relative to a plane defined by the adjacent face panel in the range of 81-87° for accommodating environmentally-induced expansion relative to adjacent panels upon installation on a roof.

Abstract: Composite roofing structures can include mineral fiber roof cover boards with high concentration of mineral wool or mineral wool and perlite. The roofing structure may include: a roof cover board including a dried base mat including: 8-25% mineral wool, 40-65% perlite, 9-15% binder, 9-15% cellulosic fiber, and 0.25-2% sizing agent, all % by weight; an insulation layer; and a roofing membrane. The roof cover board is over the insulation layer, the roofing membrane is over the roof cover board. The roof cover board is attached to the insulation layer. The roofing membrane is attached to the roof cover board. Alternatively dried base mat may include: 30-70% mineral wool, 10-50% perlite, 5-15% binder, 2-20% cellulosic fiber, and 0.25-2% sizing agent. Alternatively the dried base mat may include: 60-90% mineral wool, 0-10% fiber, 0-10% perlite, 4-10% binder, 0-5% gypsum, and 0.25-2% sizing agent.

Abstract: A gypsum fiber roofing panel with an angled edge for accommodating environmentally-induced expansion is provided, including a homogeneous body formed from a slurry of gypsum and reinforcing fibers having a face panel, a back panel, and a plurality of side edges, each side edge having an angle relative to a plane defined by the adjacent face panel in the range of 81-87° for accommodating environmentally-induced expansion relative to adjacent panels upon installation on a roof.