Wood Shingles and Shakes
Wood shingles or machine-grooved shakes are sometimes used for wall cladding. They are available in lengths of 400, 450 and 600 mm (16, 18 and 24 in.) and may be factory-painted or stained. Plywood, OSB or lumber sheathing should be used under shingles or shakes.
Shingles are separated into three grades. The first grade is composed of clear shingles, all heartwood, and all edge grain. The second grade consists of shingles with clear butts and permits defects in the part of the shingle that is normally covered in use. The third grade includes shingles that have defects other than those permitted in the second grade and are only suitable for under-coursing.
First grade material is made in random widths varying from 65 to 350 mm (21⁄2 to 14 in.) and only a small proportion of the narrow width is permitted. Shingles of a uniform width, known as dimension shingles, are also available in widths of 100, 125 or 150 mm (4, 5 or 6 in.). Table 37 (p. 306) shows the commonly used exposure and thickness of wood shingles and machine-grooved shakes.
Wood shingles are most commonly applied in a single course using first- and second-grade shingles. When the single-course application is used, offset the joints in succeeding courses at least 40 mm (19⁄16 in.), and ensure that joints in any two or three courses do not line up.
To obtain deep shadow lines, shingles can be laid in what is called double-coursing by using a lower grade shingle under the shingle exposed to the weather. The exposed shingle butt extends about 12 mm (1⁄2 in.) below the butt of the undercourse. Where double-coursing is used, wider exposure to the weather is possible. Offset joints in the outer course from joints in the undercourse by at least 40 mm (1 9⁄16 in.).
Oncodes.ca publishes this information for educational purposes only