Abstract: Disclosed is a composite gypsum board comprising a set gypsum core disposed between face (e.g., Manila) and back (e.g., Newsline) cover sheets. The set gypsum core is formed from a core slurry comprising stucco, water, and optional additives, such as foaming agent, migrating starch, accelerator, retarder, dispersant, etc. A dense layer formed from a dense layer slurry comprising stucco, water, fiber (e.g., paper fiber), and optionally, strength-enhancing starch, is disposed between the core and the face paper. The dense layer slurry contains a greater concentration of fiber, and optionally, strength-enhancing starch, than the core slurry, but the concentration of one or more other additives (e.g., accelerator, retarder, dispersant, or combinations thereof) is lower or the same in the dense slurry as compared with the core slurry. Also disclosed is a method of making board using one board mixer. In embodiments, paper fiber is added to water to form a suspension.

Abstract: A building construction product with an electroconductive surface, the building construction product comprising a core with one or more surfaces covered by an electroconductive paper comprising carbon fibers, the electroconductive paper being attached to the one or more surfaces of the core. Methods and materials for producing the building construction products with an electroconductive surface and products and methods for shielding an area from electromagnetic waves.

Abstract: A joint compound system includes a set-inhibited, pre-wetted, setting-type, ready-mix joint compound and a set initiator. The set-inhibited, pre-wetted, setting-type joint compound includes a ready-mixed, setting-type joint compound base with a calcium-free phosphate set preventing agent that impedes chemical hydration of a gypsum component of the setting-type joint compound. The joint compound base is free of calcium carbonate. The set initiator includes alum to reinitiate the chemical hydration reactions.

Abstract: The present invention is a ready-mixed, drying-type joint compound including an alkali sensitive component and a pH buffer system of a weak acid and its conjugate base to maintain pH of 8-12, typically for 120 days or more at 75° F. in a sealed container.

Abstract: An exterior sheathing cementitious panel which prevents water penetration and air leakage is provided. Methods for manufacturing exterior sheathing cementitious panels with a highly efficient integrated air/water barrier sheet are also provided. An exterior sheathing system employing the exterior sheathing cementitious panel is provided.

Abstract: A punch assembly for creating clean holes in a wallboard sheet having at least one surface with a face paper layer. The punch assembly includes a frame having a lower assembly configured to support the wallboard sheet, a plate on an upper frame assembly being reciprocable relative to the at least one surface of the wallboard sheet, at least one stripper bushing connected to the plate, where the at least one stripper bushing including a hole and a piercing edge, and at least one punch configured to move through the hole in the at least one stripper bushing. In operation, the plate is moved against the at least one surface of the wallboard sheet so that the piercing edge of the at least one stripper bushing contacts the face paper layer and at least partially cuts the face paper layer prior to the at least one punch moving through the wallboard sheet to form at least one clean hole in the wallboard sheet.

Abstract: A ready-mixed setting type joint compound in which formation of gypsum seeds has been inhibited. A method for controlling a setting reaction by mixing a ready-mixed setting type joint compound with one or more metal ion control agents comprising aminopolycarboxylic acid and/or a salt thereof, and further mixing the setting type joint compound with one or more non-calcium phosphate compounds. The method may further comprise mixing the setting type joint compound with a set activator obtained by blending together a first set activator including a cadmium compound, lead compound and/or zinc compound and a second set activator including a ferrous compound, aluminum compound and/or manganese compound.

Abstract: Method of making foamed gypsum slurry having 15 to 90 volume percent gas bubbles including: passing first slurry including water and on dry basis 50 to 98 wt. % calcium sulfate hemihydrate, 1 to 50 wt. % calcium carbonate, and 0.1 to 10 wt. % cellulose thickener via a first hose to a Wye connector conduit first inlet opening at Rate C and passing alum solution via a second hose to a second inlet opening of the conduit at Rate D to create combined mixed stream passing from the conduit to a static mixer for mixing for Time 3 to activate at least a portion of the calcium carbonate and alum to generate CO2 and create the foamed gypsum slurry; transferring the slurry from the mixer to a cavity between two wall boards via a third hose. Allowing the slurry in the cavity to expand, harden and dry.

Abstract: A gypsum slurry mixer output canister is provided, including a canister housing having an upper end, an opposite lower end and defining a canister interior, a cover secured to the upper end, a slurry inlet in operational relationship to the upper end, a spiral block associated with the upper end, and having a helical flow surface depending into the interior. A flow distributor is secured to the lower end and is in fluid communication with the interior, and a slurry outlet is defined by the lower canister housing end.

Abstract: This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.

Abstract: A modular assembly is provided and includes a modular frame to be installed at least partially below grade and at least two panels attached to the modular frame, where the at least two panels are made of a material that withstands lateral, vertical and shear forces generated by surrounding below grade materials. The modular frame and the at least two panels are joined together as a unit prior to installation.

Abstract: This invention provides gypsum wallboards with a unique microstructure where the walls between voids are enhanced in thickness and strength to substantially improve the strength and handling properties of the wallboards. A method of making lightweight gypsum wallboards is also provided.

Abstract: This invention provides low dust low density gypsum wallboard products having high total core void volumes, corresponding to low densities in the range of about 10 to 30 pcf. The wallboards have a set gypsum core formed between two substantially parallel cover sheets, the set gypsum core preferably having a total void volume from about 80% to about 92%, and made from a slurry including stucco, pregelatinized starch, and a naphthalenesulfonate dispersant. The combination of the pregelatinized starch and the naphthalenesulfonate dispersant also provides a glue-like effect in binding the set gypsum crystals together. The wallboard formulation, along with small air bubble voids (and water voids) provides dust control during cutting, sawing, routing, snapping, nailing or screwing down, or drilling of the gypsum-containing products.

Abstract: An exterior sheathing cementitious panel which prevents water penetration and air leakage is provided. Methods for manufacturing exterior sheathing cementitious panels with a highly efficient integrated air/water barrier membrane are provided as well.

Abstract: Disclosed is a method and system for blending a foam modifier with foaming agent on-line, e.g., as may be particularly useful for gypsum or cement slurries. The foam modifier comprises a fatty alcohol that is added to a gypsum or cement slurry that includes foaming agent, such as an alkyl sulfate surfactant. The fatty alcohol can be a C6-C16 fatty alcohol in some embodiments. The use of such a foam modifier can be used, for example, to stabilize the foam, reduce waste of foaming agent, improve void size control in the final product, and improve the gypsum board manufacturing process.

Abstract: A building construction product comprising an ionochromic dye, wherein the building construction product has a first color when the product comprises water, wherein the first color is dependent on the presence of metal ions in solution in the product; and wherein the product has a second color when the product has solidified. Methods of monitoring setting and drying reactions of building construction products, including setting-type and drying-type joint compounds and plasters.

Abstract: Mat-faced cementitious board including: (a) a cementitious core; (b) a fibrous mat having an inner first surface facing at least one face of the cementitious core, and an outer second surface, wherein the inner first surface and the outer second surface are opposed; (c) a hydrophobic, non-setting coating resulting from applying to the outer second surface of the fibrous mat a layer of hydrophobic finish composition including: (i) about 50 to about 80 weight % non-setting, inorganic filler having a mean particle diameter of about 12 microns to about 35 microns, (ii) about 20% to about 50 weight % an aqueous dispersion of a film-forming polymer, (iii) 0% to about 30 weight % additional water; (iv) an absence of fly ash, (v) an absence of pozzolanic material, (vi) an absence of hydraulic cement, (vii) an absence of calcium sulfate hemihydrate, and (viii) an absence of calcium sulfate anhydrite.

Abstract: Continuous method including mixing water and cementitous powder to form slurry; mixing the slurry and reinforcement fibers in a single pass horizontal continuous mixer to form fiber-slurry mixture, the mixer including an elongated mixing chamber having a reinforcement fiber inlet port, and upstream of the fiber inlet port is an inlet port to introduce water and cementitous powder together as one stream or at least two inlet ports to introduce water and dry cementitous powder separately as separate streams into the chamber, a rotating horizontal shaft/s within the chamber, part of the chamber for mixing the fibers and slurry and moving the fiber-slurry mixture to a mixture outlet; discharging the fiber-slurry mixture from the mixer outlet; forming and setting the fiber-slurry mixture on a moving surface; cutting the set mixture into fiber reinforced concrete panels and removing the panels from the moving surface.

Abstract: Embodiments of a system and a method for manufacturing a gypsum board can be used to produce a gypsum board having at least one perforated cover sheet via a cover sheet perforator system. The cover sheet perforator system can include a perforator roller is disposed downstream of a forming station along a machine direction, a roller support frame for rotatably supporting the perforator roller such that its rotational axis extends along the cross-machine direction, and a motor arranged with the perforator roller to rotate the perforator roller about the rotational axis. The drive motor can be adapted to rotate the perforator roller with a tangential speed substantially equal to the line speed to produce a series of perforation holes in an upwardly-facing cover sheet as the gypsum board moves past the perforator roller.

Abstract: Gypsum boards formed from synthetic gypsum and other gypsum sources having high chloride salt concentrations. Gypsum boards may include a board core including set gypsum. A total concentration of the chloride anion in the board core ranges from about 500 ppm to about 3000 ppm, typically about 1000 ppm to about 3000 ppm, based on weight of the calcium sulfate hemihydrate. An inner surface of a front paper cover sheet contacts a first face of the board core. An inner surface of a back paper cover sheet contacts a second face of the board core. A starch layer coats the inner surface of at least one of the front and back cover sheet. Methods of making the gypsum board, and a wall system for employing the gypsum boards, are also provided.