Abstract: A process for making a thin, sealant-coated, fire and indentation resistant gypsum panel. A layer of a mixture of cellulosic fibers moistened with water and an additive to restrict the adhesion of cellulosic fibers to one another, is deposited on at least two separate conveyors to form a fibrous matt on each conveyor. A layer of dry calcined gypsum containing set accelerator is deposited on the fibrous matt on each conveyor which contains, by weight on a dry weight basis, about 70-90% gypsum, about 10%-19% cellulosic fiber and about 1%-9% of combined additive and set accelerator. Each layer on each conveyor is directed to a mixing station to form a homogeneous layer, and the formed homogeneous layers on separate conveyors are placed atop one another on a single conveyor to form a combined homogeneous layer. Water is added to the layer or layers to rehydrate calcined gypsum. The combined homogeneous layer is subjected to pressure to form a pressed, homogeneous fiber-reinforced gypsum panel, and dried.

Abstract: The invention is directed to a tongue and groove product which comprises a first and second major surface and a first and second longitudinal edge. The first longitudinally edge includes a longitudinally-extending groove. The second longitudinal edge includes a longitudinally-extending protruding tongue for interlockingly engaging a complimentary grooved longitudinal edge of an adjacent tongue and groove board. The protruding tongue has an upper and a lower longitudinally-extending surface. The major design feature of this invention is that the protruding tongue has at least one substantially vertically-extending opening formed therein. Each of the openings extends through the protruding tongue from said longitudinally-extending upper surface to said longitudinally-extending lower surface for providing at least one drain path for water to drain by gravity from said first major surface downwardly through each said vertically-extending opening.

Abstract: The invention is directed to a tongue and groove product which comprises a first and second major surface and a first and second longitudinal edge. The first longitudinally edge including means defines a longitudinally-extending groove. The second longitudinal edge includes a longitudinally-extending protruding tongue for interlockingly engaging a complimentary grooved longitudinal edge of an adjacent tongue and groove board. The protruding tongue has an upper and a lower longitudinally-extending surface. The major design feature of this invention is that the protruding tongue has at least one substantially vertically-extending opening formed therein. Each of the openings extends through the protruding tongue from said longitudinally-extending upper surface to said longitudinally-extending lower surface for providing at least one drain path for water to drain by gravity from said first major surface downwardly through each said vertically-extending opening.