Definition
Drywall (also known as gypsum board, sheetrock, or plasterboard) is a panel made of gypsum plaster pressed between two thick sheets of paper. It is used to create interior walls and ceilings. Standard drywall sheets are 4 feet wide and come in lengths of 8, 10, 12, and 14 feet. Thickness options include 1/4 inch (curved surfaces), 3/8 inch (repair), 1/2 inch (standard walls), and 5/8 inch (fire-rated and ceilings).
Formula
Standard 4x8 sheets cover 32 sq ft, 4x10 sheets cover 40 sq ft, and 4x12 sheets cover 48 sq ft. Add 10-15% for waste. For ceilings, use 5/8 inch thick panels. For wet areas like bathrooms, use moisture-resistant (green board) or cement board.
Example
Drywall Calculation Example
A 12x12 room with 8-foot ceilings has approximately 384 sq ft of wall area (12+12+12+12 x 8). Subtracting 48 sq ft for windows and 21 sq ft for doors leaves 315 sq ft. Using 4x8 sheets (32 sq ft each), you need 10 sheets plus 10-15% waste = 11-12 sheets. Consider 4x12 sheets for fewer seams.