The Ontario Building Code | Swelling and Shrinking Soils
4.2.4.11. Swelling and Shrinking soils
(1) Where swelling or shrinking soils, in which movements resulting from moisture content changes may be sufficient to cause damage to a structure, are encountered or known to exist, such a condition shall be fully investigated and provided for in the design.
In Plain Language
Where swelling or shrinking soils, whose volume changes significantly with moisture content, could cause enough movement to damage the building, the foundation design must specifically account for that soil behaviour.
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.