Cedar Shake Shingles
According to the U.S. Forest Products Laboratory, “...a good wood shingle roof will last up to thirty years under favorable conditions” (see USDA Handbook 481). Care and mainte- nance are the keys: The better care you take of your shakes and shingles, the longer you can expect your roof to last.
The simplest form of wood shingle is a rectangle about 16 inches (41 cm) long. The sides and butt of a shingle are often irregular; the sides may taper and the butt may not be square with the sides. Shingles that have been processed so that the butt is square to the sides are called rebutted and re-squared or rebutted and re-jointed shingles, often abbreviated R&R.
Shingles and shakes may be tapered, straight, split or sawn and any combination of these except straight-tapered. Different species and quality of wood are used as are different lengths and installation methods. Shakes and shingles may also be treated with wood preservatives and fire retardants before or after installation.