Wood shingles are cut and sawn to specific sizes and can be installed as roofing or wall siding. They are most commonly made from red cedar due to red cedar's availability and natural resistance to rot. Sometimes other rot-resistant species are used including white cedar, redwood and cypress (yellow cedar). Soft wood species such as pine require special installation and treatment to minimize weathering problems.
Wood shingles come in three lengths and have three seemingly unrelated industry names. 16" long shingles are called "5X" or "Fivex", 18" long shingles are called "perfections" and 24" long shingles are called "Royals." Thicknesses of the shingles also vary slightly. 16" 5X shingles average 0.40" thick; 18″ Perfections average 0.45″ thick and 24″ Royals are about 0.50″ thick.
Red cedar shingles come in three finish grades called (in decreasing order of quality) No. 1 Blue Label, No. 2 Red Label and No. 3 Black Label. A fourth grade is used for under-coursing and is called No. 4 Green Label. No. 1 Blue Label shingles are made from the best heartwood and are 100% clear. No. 2 Red Label are made from wood that did not make the No. 1 grade and can include some sapwood and flat grain. The exposure face however should have limited defects. No. 3 Black Label shingles can have unlimited sapwood and flat grain and should not be used on a house. No. 3 is more of a utility grade shingle.
Unlike asphalt shingles, the amount of exposed surface a wood shingle presents to the weather will vary by roof pitch, shingle length and shingle grade.
For roof pitches of 3:12 and 4:12, a 16" 5X shingle will have between 3-3/4" to 3" of exposure (lower quality shingle requires less weather exposure); an 18" Perfection will have between 4-1/4" to 3-1/2" exposure and a 24" Royal will have between 5-3/4" and 5" of exposure.
As roof pitch increases, so may the exposure of weathered surface. As a result, for roof pitches of 5:12 to 12:12, a 16" 5X shingle will have between 5" to 3-1/2" of exposure; an 18" Perfection can have between 5-1/2" to 4" exposure and a 24" Royal will have between 7-1/2" and 5-1/2" of exposure.
A cedar wood roof can cost 2.5 times the cost of a commodity 3-tab asphalt roof; 2.0 times the cost of a mid-level laminated asphalt roof or 1.5 times the cost of a premium laminated dimensional asphalt roof.
As with all sloping roof materials, it is important to have proper roof ventilation. Properly installed, wood shingles can last 20 to 40+ years depending on the quality of the wood, location of the home and the quality of the installation.