A fire-resistant gypsum panel comprises: a gypsum core layer comprising set gypsum and a high temperature sag-resistant material including mineral wool in an amount between 0.2% and 3.0% by weight of gypsum.

Systems and methods for making gypsum board using a liquid gypsum set accelerator. Stucco and water are mixed to form a gypsum slurry, such as in a pin mixer. A gypsum set accelerator is mixed with a liquid medium to form a liquid gypsum set accelerator, such as in an eductor. The liquid gypsum set accelerator is added to the gypsum slurry, which is shaped to form the gypsum board.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

An impact resistant exterior sheathing gypsum building panel with an integrated impact resistant woven mesh which protects against impact from projectiles such as those conveyed by hurricane force winds is provided. Methods for manufacturing these exterior sheathing gypsum building panels with an integrated impact resistant woven mesh are also provided. An exterior sheathing system employing the exterior sheathing cementitious building panel is provided.

In general, the present invention is directed to a gypsum board comprising a gypsum core and a glass mat facing material including a coating. The coating comprises a resin including an acrylic resin, a siloxane rubber, or a mixture thereof and hydrophobic additive comprising an organosilane. The gypsum board passes at least one of the three air and water barrier tests specified in AC-212 wherein the tests comprise a water penetration barrier test as conducted in accordance with ASTM E331-00, a hydrostatic head test as conducted in accordance with AATCC 127-2008, or an air barrier test as conducted in accordance with ASTM E2357-11.

Gypsum panels and methods for their manufacture are provided herein. The gypsum panels include a gypsum core having a first surface and a second opposed surface and a first fiberglass mat associated with the first surface of the gypsum core, such that gypsum from the gypsum core penetrates at least a portion of the first fiberglass mat.

An uncoated nonwoven fibrous mat having a reduced air porosity is disclosed comprising a first plurality of fibers having a length between about 10 mm and 20 mm and an average diameter between about 9 μm and 15 μm; a second plurality of fibers having a length between about 3 mm and 8 mm and an average diameter between about 5 μm and 8 μm; and a binder composition. The uncoated nonwoven fibrous mat has an air porosity less than about 550 CFM.

In general, the present invention is directed to the use of particular phosphorus containing compounds for making a glass mat faced gypsum board. The phosphorus containing compound may be a phosphite or a phosphate having a certain formula. In this regard, the present invention is directed to a glass mat faced gypsum board including a gypsum core that is formed from a gypsum slurry comprising such phosphorus containing compound. The present invention is also directed to a method of making a glass mat faced gypsum board.

The invention refers to a fungicide mixture comprising the biocides TBZ and PYM in the weight ratio of 20:1 to 1.1:1, in particular 10:1 to 1.1:1, preferably 5:1 to 1.1:1, wherein the total amount of TBZ and PYM based on the entire amount of biocidal actives is greater than 99 wt. % and its use for protecting wallboards.

A high temperature sag resistant lightweight wallboard. The addition of a small amount of urea (about 0.1%) significantly improves the high-temperature sag resistance on Type X gypsum wallboards. These gypsum wallboards may have a board weight of less than 2100 lbs/msf when cast to have an overall 5.8 inch thickness, and may include glass fibers and/or mineral wool. Also, methods of making the gypsum wallboard and a wall system for employing the gypsum wallboard.