CGC - Ultralight 1/2" Interior Ceiling Board 4' x 8' Ceiling Drywall or Gypsum Panels are designed for interior ceiling applications where there is a greater demand for sag resistant performance. These superior-grade panels are only 1/2" thick, but offer significantly improved sag resistance when compared to 1/2" Standard or 5/8" Type X gypsum panels. Ceiling Drywall is lighter in weight, which helps ease handling and installation. They can be attached with long edges parallel or perpendicular to framing. NOTE: Ceiling drywall is code for ceilings with framing spacing greater than 19" OC. A Product of Canada. Data Sheet