2.2.1 Shakes: The shakes
are manufactured with a blend of poly resins, fire-retardant, viscosity modifier,
plasticizer, isocyanate and mineral solids, and are shaped to simulate wood shakes. The
products are nominally 5½ inches (140 mm), 9½ inches (241 mm) or 13¼ inches (336 mm)
wide; 21½ inches (546 mm) long; and 5/16 inch to ¾ inch (7.9 mm to 19.1 mm) thick at the
butt end and 1/8 inch (3.2 mm) thick at the tapered end. The
installed weight of the shakes is 3 pounds per square foot (14.6 kg/m2) when installed with 10-inch (254 mm) exposure. See Figure 1 for
additional details.
2.2.2 Fasteners: Fasteners
are 5d, galvanized steel, aluminum or stainless steel box nails with a 7/32-inch-diameter head; or No. 16 gage
[0.062 inch (1.57 mm)], 7/16-inch-crown (11.1 mm), anti-backout-style
galvanized steel staples.
2.2.3 Underlayment: Roof underlayment and interlayment shall be manufactured under the
listing program of an agency having an lCBO ES or NES report.
2.3 Installation:
2.3.1 Class A Assembly:
Shakes are installed on code-complying, minimum 15/32-inch-thick
(11.9 mm) solid sheathing or minimum ¾-inch-thick (19.1 mm), filled-in
spaced sheathing with a maximum spacing of ½ inch (12.7 mm) between boards. A layer of
Type 30 roofing felt underlayment over the sheathing, and a layer of Type 30 roofing felt
interlayment installed between courses, shall be applied in such a manner that no felt is
exposed to weather. Minimum roof slope is 3:12 and maximum roof slope is 21:12.
Class B Assembly: The
shakes are installed on code-complying spaced sheathing. Where shakes are required
to be fastened, spaces between sheathing boards must be filled. The interlayment,
underlayment and roof slope are as noted in Section 2.3.1.
2.3.2 Severe Climate Areas:
In areas subject to wind-driven snow, ice buildup, or wind-driven dust or sand (or in
other areas, as designated by Everlast Systems, Inc., or the building official), in
addition to one layer of Type 30 felt installed over solid sheathing, two layers of Type
15 felt are applied shingle-fashion, and solid-cemented together with approved cementing
material between the plies. The two layers extend from the eave up the roof to a point 36
inches (914 mm) inside the exterior wall line of the building.
2.3.3 Application: A
36-inch-wide (914 mm), Type 30 roofing felt is laid over the deck. The starter course must
be doubled at the eave line. The butts of the first course should project 1 to 1½ inches
(25.4 to 38 mm) from the sheathing. After each subsequent course, an 18-inch-wide (457 mm)
strip of Type 30 felt is laid over the top portion of the shakes extending onto the
sheathing, with the bottom edge of the felt positioned at a distance above the butt equal
to twice the weather exposure.
Individual shakes are
spaced between 3/8 and ½ inch (9.5 and 12.7 mm) apart. Spaces must be
offset at least 1½ inches (38 mm) in adjacent courses and out of direct alignment in
alternate courses. Two fasteners are used for all three sizes of shakes. Fasteners are
placed 10½ to 11 inches (267 to 279 mm) from the butt end and 1½ to 2 inches (38 to 51
mm) in from each edge. Fasteners must be long enough to penetrate the sheathing at least
¾ inch (19.1 mm) or through its thickness, whichever is less. If stapling, crowns must be
parallel to the shake butt. Installation of shakes must be at ambient temperatures above
45°F (7.2°C). See Figure 2 for typical installation details.
2.3.4 Shake Repair: Broken
or damaged shakes are removed by sawing off the fasteners on each edge of the broken
shake, and on the shake above it, with a shake saw. Existing fasteners must be removed and
the nail hole sealed with an approved sealant. Any damage to existing underlayment must be
repaired prior to installation of the replacement shake. A new shake of the same size is
inserted into the open space, maintaining head and side laps. The shake is secured with
approved plastic cement or adhesive, or a fastener noted in Section 2.2.2 of this report.
