The Installation of a Wood Roof

Shingles

• A wood shingle is thinner than a shake, and is tapered and sawn smooth on both faces to present a more finished appearance. It can be installed on solid or spaced sheathing, but the latter requires boards measuring more than 1-by-4 inches, and spaced on centers that account for placement of fasteners. The slope of the roof deck must rise at least three units for every 12 inches of horizontal movement. This is equal to a minimum 25-percent slope or 3:12 grade. The material requires an underlayment. In areas where ice forms along the eaves to back water up into the roof, the underlayment must consist of two layers cemented together to form an ice barrier. An alternative for this barrier is self-adhering polymer modified bitumen that must extend at least 24 inches inside the exterior wall line of the structure.

Shakes

• A wood shake is thicker than a shingle and split across the natural face of the wood to show a textured surface on the exposed face. Shakes can be installed using the same standards as shingles. However, when 1-by-4 boards are installed on sheathing spaced at 10 inches on center, additional 1-by-4 boards are needed between the sheathing boards. The deck slope must also be a minimum of 3:12 grade or 25-percent slope. An underlayment is required with the same standards as shingles. Interlayment is also needed, which are sheets of building material placed between courses of shakes, rather than directly on the deck.

Fasteners

• Wood roofs can be attached to the roof deck with nails of galvanized or stainless steel, or non-corroding metal staples. Each shake or shingle needs a minimum of two fasteners that are long enough to penetrate through all roofing material layers. The fasteners must extend through the underside of the roof deck, and penetrate the wood planks or boards to a depth of at least 0.75 inches.

Cost

• The price of installing a wood roof primarily depends on the square footage, since that dictates the amount of material used. According to Cost Owl, with prices accurate at the time of publication, wood shake roofs run from $2 to $3.25 per square foot, including materials and installation. This puts the total price of a 2,000-square-foot surface at between $4,000 and $6,500. Factors that affect price include steepness of slope and the accessibility of the roof.