The Ontario Building Code | Attachment of Cladding to Sheathing
9.23.16.3. Attachment of Cladding to Sheathing
(1) gypsum sheathing, rigid insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation and fibreboard shall not be used for the attachment of siding materials.
(2) Nails used in attaching the materials listed in Sentence (1) shall be not less than 3.2 mm diam with a minimum head diameter of 11 mm.