Wood Shingle Installation

Wood shingles are sawn, tapered pieces of wood, usually western red cedar in North America and other durable species elsewhere. Unlike shakes, they are smooth and lie close together, so they are normally installed without felt interlay and give roughly three layers of coverage at any point.

Deck

Wood shingles can be laid on solid sheathing or on spaced (skip) sheathing. With spaced boards, Canadian guidance sets the board spacing equal to the shingle exposure so that each course has a board to nail into.

Spacing and edges

• A gap of about 6.4 mm (1/4 in) between shingles allows them to swell when wet without buckling.
• Side laps between successive courses are at least 38 mm (1 1/2 in), and joints separated by only one course should not line up.
• Eave overhang is about 32-38 mm (1 1/4-1 1/2 in) and rake overhang about 19-25 mm (3/4-1 in).
• The first course is doubled (or tripled) at the eave.

Exposure

Canadian guidance, drawing on Cedar Shake and Shingle Bureau grades, gives maximum exposures for No. 1 grade shingles:

Length	Pitch 4:12 or steeper	Pitch 3:12 to under 4:12
400 mm (16 in)	125 mm (5 in)	95 mm (3 4/5 in)
450 mm (18 in)	140 mm (5 1/2 in)	100 mm (4 in)
600 mm (24 in)	189 mm (7 1/2 in)	146 mm (5 4/5 in)

Lower grades require less exposure.

Nailing

• Two nails per shingle regardless of width, within about 19 mm (3/4 in) of each edge.
• Nails placed high enough to be covered by the next course; nailing too high or too far from the edges encourages curling.
• Corrosion-resistant nails only: hot-dip galvanized, aluminium or stainless steel. Plain steel nails stain and fail.
• Typical sizes are 3d for 16 and 18 in shingles and 4d for 24 in shingles, with longer nails for re-roofs and ridges.

Ridge and hips

Ridges are formed from pairs of shingles with alternating overlaps, fastened with two nails per side and laid at the same exposure as the field.