Gypsum Board Maximum Spacing of Supports

(1)  Maximum spacing of supports for gypsum board applied as a single layer shall conform to Table

Article Ontario Regulation 332/12 Building Code,   Information published by for educational purposes only.


Gypsum board is the most widely used interior finish because of its speed of installation, low cost, consistent result and fire resistance. Several types have special characteristics such as additional fire resistance or water resistance for use in humid areas such as bathrooms. Various accessories such as corner beads and coves are also available.

Gypsum board is a sheet material composed of gypsum filler between two layers of paper. Sheets are 1.22 m (4 ft.) wide and are supplied in various lengths, 2.44 m (8 ft.) and longer. The edges along the length of the sheet are tapered on one face to receive joint compound and tape. To obtain an even surface, install gypsum on studs and ceiling joists and furring strips that are straight and aligned.

Although 9.5 mm (3⁄8 in.) thick gypsum board may be used on walls with support spacings up to 400 mm (16 in.) on centre when the boards are oriented perpendicular to the framing, 12.7 mm (1⁄2 in.) gypsum board is more commonly used because of its extra stiffness and strength. Where supports are spaced at 600 mm (24 in.) on centre, the minimum thickness should be 12.7 mm (1⁄2 in.). When gypsum board supports insulation, it must be at least 12.7 mm (1⁄2 in.) thick. Some ceiling gypsum board is specially designed to resist sagging when water-based textured finishes are applied to a ceiling. A 12.7 mm (1⁄2 in.) panel can be installed perpendicular to supports at spacings up to 600 mm (24 in.).

Application of drywall finish

Source : Canada Mortgage and Housing Corporation (CMHC)

Note: Drywall is a material used for interior walls, ceilings and roofs made from gypsum plasterboard sheets. Plasterboard panels are faced with paper facer or other suitable material (referred to as “backer”), and covered by an appropriate sealant. Drywall is used in residential and commercial construction because of its strength, resistance to water, fire resistance, and durability.