The Ontario Building Code | Joints to be Offset or Reinforced
9.20.9.1. Joints to be Offset or Reinforced
(1) Vertical joints in adjacent masonry courses shall be offset unless each wythe of masonry is reinforced with the equivalent of no fewer than two corrosion-resistant steel bars of 3.76 mm diam placed in the horizontal joints at vertical intervals not exceeding 460 mm.
(2) Where joints in the reinforcing referred to in Sentence (1) occur, the bars shall be lapped not less than 150 mm.
In Plain Language
Masonry joints must be offset (staggered) or reinforced as set out in this article, since continuous, unstaggered joints running through a wall create a weak plane.
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.