The Ontario Building Code | Support of Shallow Foundations
4.2.6.2. support of Shallow foundations
(1) Where a shallow foundation is to be placed on soil or rock, the soil or rock shall be cleaned of loose and unsound material and shall be adequate to support the design load taking into account temperature, precipitation, construction activities and other factors that may lead to changes of the properties of soilor rock.
In Plain Language
Where a shallow foundation is placed on soil or rock, that bearing surface must first be cleaned of loose and unsound material, ensuring the foundation actually bears on the sound material the design assumed.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.