The Ontario Building Code | Reduction in Thickness
220.127.116.11. Reduction in Thickness
(1) Where the top of a foundation wall is reduced in thickness to permit the installation of floor joists, the reduced section shall be not more than 350 mm high and not less than 90 mm thick.
(2) Where the top of a foundation wall is reduced in thickness to permit the installation of a masonry exterior facing, the reduced section shall be,
(a) not less than 90 mm thick, and
(b) tied to the facing material with metal ties conforming to Sentence 18.104.22.168.(3) spaced not more than,
(i) 200 mm o.c. vertically, and
(ii) 900 mm o.c. horizontally.
(3) The space between wall and facing described in Sentence (2) shall be filled with mortar.