The Ontario Building Code | Altered Subsurface Condition
4.2.2.3. Altered Subsurface Condition
(1) If during construction, the soil, rock or groundwater is found not to be of the type or in the condition used in design, and as indicated on the drawings, the design shall be reassessed by the designer.
(2) If during construction, climatic or any other conditions have changed the properties of the soil, rock or groundwater, the design shall be reassessed by the designer.
4.2.3. Materials Used in foundations
In Plain Language
If soil, rock, or groundwater conditions found during construction differ from what the design assumed, the design must be reviewed and, if necessary, revised to reflect the actual site conditions encountered.
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.