Most wood shingle roofs are made from western red cedar for its durability and resistance to insect damage; some are made from preservative-treated pine or similar species. Wood shingles are smooth; more rustic, rough-hewn shingles are called shakes. Shingles and shakes come in varying lengths, usually 16, 18, or 24 inches and in random widths.
Shingles typically nailed to 1-by-6-inch boards spaced a few inches apart, a form of construction that allows air circulation under the wood to prevent the shingles from becoming soggy. Shakes, on the other hand, are laid so that each course alternates with strips of roofing felt, a method that ensures a weather-tight surface.
Shingles and shakes can be applied directly over some existing roofing materials, such as asphalt shingles or a previous layer of wood shingles.
