The Ontario Building Code | Intersection of Shingle Roofs and Walls Other Than Masonry
9.26.4.5. Intersection of Shingle Roofs and walls Other Than masonry
(1) The intersection of shingle roofs and walls clad with other than masonry shall be protected with flashing.
(2) Flashing required in Sentence (1) shall be installed so that it extends up the wall not less than 75 mm behind the sheathing paper, and extends not less than 75 mm horizontally.
(3) Along the slope of the roof, the flashing required in Sentence (1) shall be stepped with not less than a 75 mm head lap.