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 | Lateral Support Required

9.20.10.1. Lateral support Required

(1) masonry walls shall be laterally supported by floor or roof construction or by intersecting masonry walls or buttresses.

(2) The spacing of supports required in Sentence (1) shall be not more than,

(a) 20 times the wall thickness for all loadbearing walls and exterior non-loadbearing walls, and

(b) 36 times the wall thickness for interior non-loadbearing walls.

(3) In applying Sentence (2), the thickness of cavity wallsshall be taken as the greater of,

(a) two-thirds of the sum of the thicknesses of the wythes, or

(b) the thickness of the thicker wythe.

(4) floor and roof structural elements providing lateral support for walls as required in Sentence (1) shall be constructed to transfer lateral loads to walls or buttresses approximately at right angles to the laterally supported walls.

9.20.11. Anchorage of Roofs, floors and Intersecting walls

In Plain Language

Masonry walls need lateral support at intervals set out in this article, preventing the wall from buckling or toppling sideways.

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.