Fastening to Lath,
(1) When lath is used with double-course application (see Sentence 9.27.5.1.(4)), 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).
(5) If wood lath is not used, the butts of the under-course shingles or shakes of the application referred to in Sentence (1) shall be located 12 mm above the butts of the outer course.
Article 9.27.7.5 Ontario Regulation 332/12 Building Code, O. Reg. 332/12: BUILDING CODE (ontario.ca) © Queen’s Printer for Ontario, 2021
