Shake (shingle)
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A shake is a wooden shingle that is made from split logs. When these are used for covering the top of a house, the result is a shake roof.
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[edit] Wood selection
In North America shakes are typically made from Western Redcedar (Thuja plicata), while in Scandinavia and Central Europe they are more commonly made from pine (Pinus sylvestris). There are various types of shakes, the main differentiating feature between shakes and other types of shingles is that shakes are split while most shingles are sawn on all sides. Shakes can be made in 24-inch lengths - the most common, 18-inch barn shake, or even 48-inch shakes, which are typically used for siding. Likewise wooden shingles are manufactured in differing lengths, 15-inch, 18-inch - common, and 24" which are known as heavy.
Both shakes and wooden shingles are typically cut from salvage logs, dead trees which were left from previous logging operations, or selective logging of dead and down, or dead and standing trees, this depends on area licensing.
[edit] Log handling and transportation
Logs are typically cut into appropriate lengths using a chainsaw, then the "ringers" or cuts are split with an axe into cubes which are small enough to handle, usually 100 to 450 pounds, then stacked on a rope. The rope is looped around the stacked wood and the ends passed through an eye spliced in the end. When the running end is pulled it tightens the "sling" rope around the blocks preventing them from falling out. The slings are then flown to a central location where they can be loaded on pallets for transport. Previously swede saws, crosscut saws and hand saws may have been used to cut the logs, and a froe, a heavy blade 24 inches long and three inches wide, with a handle at one end, perpendicular to the blade) was used to split the ringers. This blade was driven into the wood using a mallet, then the wood could be pried apart by pulling on the handle if it would not split by driving the blade in alone.
Before helicopters came into common use for transporting the slings they were sometimes processed in the bush and finished, hand-split, shakes were carried out in a pack frame. In steep areas cables were strung along the slope to form a tight-line or tyrolean. Staples were driven into a block, straddling the cable, and the block was slid down the cable to a landing accessible to a boat or truck.
[edit] Cutting
Both shakes and shingles must be edge grain cut, to prevent warping and splitting as the wood dries. When splitting blocks and manufacturing shakes or shingles particular care must be taken to consider the orientation of the grain in the wood. Like-wise when bucking, care must be taken to ensure cuts are precisely perpendicular to the grain, to minimize waste and maintain product quality. When bucking, the log must be cleared off well, so the grain can be seen clearly, allowing straight cuts perpendicular to the grain. When splitting, the ringers are typically split from the bark to the heart, perpendicular to the grain. The heart wood is removed by splitting parallel to the grain, and the bark and sap-wood is removed, as well as any imperfections such as rot or bug holes. The initial split is always made on a knot, burl, check or other imperfection, to allow the blocks to made as large as possible while disposing of any waste. The blocks should never be split where there is clear wood, or imperfections will be left in the block; or the block will have to be split too small in the process of removing flaws.
When cutting large logs or severely twisted pieces, it is often necessary to "cant", or split the entire log into "slabs". To split a log a ringer is removed at each end of the tree, exposing the interior. Wedges are driven into the face to split off a slab, usually on a natural check or imperfection which runs the entire length of the log. After the face begins to separate, wedges are driven into the resultant opening, starting very near the face and progressively working toward the other end of the log in small steps.
[edit] Manufacture of shakes and shingles from block form
Shake blocks are split into 1 inch thick slats called blanks, using either a hydraulic press with a blade attached, called a cuber, or split by hand using a froe and mallet. These blanks are uniform in thickness throughout if split from the same edge without flipping the block. Alternatively, the splitter may flip the block after a blank is taken off each edge, which results in a tapered split from end to end, called tapers or hand-split. The blanks which are not tapered require further processing before application to create this taper, and are run through a large band saw, pushed by hand to cut them from corner to corner forming a tapered shake, sawn on one face.
Shingles are cut from the blocks using a circular saw, typically 42-48" in diameter. The blocks are clamped in a carriage which slides back and forth across the blade, tilting and moving the block closer to the blade with each pass to automatically form a tapered cut of the correct thickness. The edges of the shingle are then cut with another circular saw called a "trim saw", to remove irregular edges. The result is a tapered shingle sawn on all six sides. The thickness of the butt, or thicker end of the tapered cut, is usually 3/8" thick, but is also commonly made to be 5/8", and can be made to any custom specifications.
