The Ontario Building Code | Protection of Interior Finish
22.214.171.124. Protection of interior Finish
(1) Except as provided in Sentence (3), where the interior finish of the exterior walls of a building is a type that may be damaged by moisture, exterior masonry walls, other than cavity wallsor walls that are protected for their full height by a roof of a carport or porch, shall be,
(a) parged on the interior surface, and
(3) Where the insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation effectively limits the passage of water vapour and is applied by a waterproof adhesive or by mortar directly to the masonry, the requirements for sheathing paper do not apply.