CSA O118.1, "Western Red Cedar Shakes and Shingles," or
CSA O118.2, "Eastern White Cedar Shingles."
Western cedar shakes shall be not less than No. 1 or Handsplit grade, and western cedar shingles not less than No. 2 grade, except that No. 3 grade may be used for undercoursing.
Eastern white cedar shingles shall be at least B (clear) grade, except that C grade may be used for the lower course of double course applications.
9.27.7.2.
Width
Shingles and shakes shall be not less than 65 mm or more than 350 mm wide.
9.27.7.3.
Fasteners
Shingles or shakes shall be fastened with nails or staples located approximately 20 mm from each edge and not less than 25 mm above the exposure line for single-course applications, or approximately 50 mm above the butt for double-course applications.
9.27.7.4.
Offsetting of Joints
In single-course application, joints in succeeding courses shall be offset not less than 40 mm so that joints in any 2 of 3 consecutive courses are staggered.
In double-course application, joints in the outer course shall be offset from joints in the under-course by not less than 40 mm, and joints in succeeding courses shall be offset not less than 40 mm.
9.27.7.5.
Fastening to Lath
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.
The butts of the under-course of the application referred to in Sentence (1) shall rest on the top edge of the lath.
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.
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).
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.
9.27.7.6.
Exposure and Thickness
The exposure and butt thickness of shingles and shakes shall conform to Table 9.27.7.6.
Table 9.27.7.6.
Exposure and Thickness of Wood Shingles and Shakes
Forming Part of Sentence 9.27.7.6.(1)
