Gypsumboard

Gypsumboard, also known as drywall or plasterboard, is a panel made of gypsum plaster bonded between two sheets of paper. It is widely used for interior walls and ceilings because of its smooth surface, fire resistance, and ease of installation.

The core is calcium sulfate dihydrate (gypsum) with minor additives. Panels are made by forming a gypsum slurry between facing papers, pressing, and drying. Standard panels measure 4 by 8 feet, with thicknesses typically ranging from ¼ to 5/8 inch; edges are prepared to accept joints.

Common varieties include regular gypsum board for general interior use, moisture-resistant boards for bathrooms and kitchens, and fire-rated Type X boards with additives or reinforcement for improved fire resistance. There are also specialty boards for impact resistance and sound control. Gypsum boards are not suitable for exterior use.

Installers fasten panels to studs with screws, then seal joints with paper tape and joint compound. Finishing involves sanding and priming before painting or applying decorative finishes. In damp environments, selecting appropriate products and detailing reduces moisture-related damage.

Gypsum is generally non-toxic and recyclable. Waste gypsum may be repurposed in cement kilns. Health considerations include dust during cutting, requiring appropriate ventilation and personal protection. Standards such as ASTM C1396 govern gypsum board products in North America.