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.

The Ontario Building Code | Hollow Masonry Units

9.20.4.3. Hollow masonry Units

(1) Hollow masonry units shall be laid with mortar applied to head and bed joints of both inner and outer face shells.

(2) Vertically aligned webs of hollow masonry units shall be laid in a full bed of mortar,

(a) under the starting course,

(b) in all courses of columns, and

(c) where adjacent to cells or cavities that are to be filled with grout.

9.20.5. masonry Support

In Plain Language

Hollow masonry units have their own specific requirements set out in this article, addressing their different structural behaviour compared to solid units.

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.