The Ontario Building Code | Depth of Foundations
220.127.116.11. Depth of foundations
(1) Except as permitted in Sentence (2), the bearing surface of afoundation shall be below the level of potential damage, including damage resulting from frost action, and the foundation shall be designed to prevent damage resulting from adfreezing and frost jacking.
(a) is designed against frost action, or
(b) overlies material not susceptible to frost action.