Length of Fasteners Gypsum Board

(1)  The length of fasteners for gypsum board shall conform to Table, except that lesser depths of penetration are permitted for assemblies required to have a fire-resistance rating provided it can be shown, on the basis of fire tests, that such depths are adequate for the required rating.

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

Application of drywall finish

Source : Canada Mortgage and Housing Corporation (CMHC)