The Ontario Building Code | Fastening to Lath
220.127.116.11. Fastening to Lath
(1) When lath is used with double-course application (see Sentence 18.104.22.168.(5)), it shall be spaced according to the exposure and securely fastened to the framing.
(2) The butts of the under-course of the application referred to in Sentence (1) shall rest on the top edge of the lath.
(3) The outer course of the application referred to in Sentence (1) shall be fastened to the lath with nails of sufficient length to penetrate through the lath.
(4) The butts of the shingles or shakes shall be so located that they project not less than 12 mm below the bottom edge of the lath referred to in Sentence (1).