Notice: This site currently shows the 2012/2017 edition of the Ontario Building Code. The current legally effective code is the 2024 edition (O.Reg. 163/24), in effect since January 1, 2025. Confirm current requirements at ontario.ca.
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The Ontario Building Code | Unit Masonry Construction

9.15.2.2. Unit masonry Construction

(1) Concrete block shall conform to CAN/CSA-A165.1, "Concrete Block masonry Units", and shall have a compressive strength over the average net cross-sectional area of the block of not less than 15 MPa.

(2) mortar, grout, mortar joints, corbelling and protection for unit masonry shall conform to Section 9.20.

(3) For concrete block foundation walls required to be reinforced,

(a) mortar shall be Type S, conforming to CAN/CSA-A179, "mortar and Grout for Unit masonry",

(b) grout shall be coarse, conforming to CAN/CSA-A179, "mortar and Grout for Unit masonry", and

(c) placement of grout shall conform to CAN/CSA-A371, "masonry Construction for buildings".

In Plain Language

Unit masonry construction, such as concrete block foundations, must meet the requirements set out in this article, an alternative to poured concrete for foundation walls.

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.