Chipped Shingles is the best quality shingles, because of its surface has a integral unbroken wood fibers unlike sawn shingles. Chipped shingles are more durable (lifetime is more than 50 years) and have excllent waterproof properties.
Sawn Shingles are produced by sawing woodblocks on the right tiles. Compared with chipped shingles they are less durable due to the broken structure of wood fibers (lifetime is about 20 years) and have good waterproof properties.
Grade 1: face side is practically free of wood defects; most of the wood fibers are parallel to the tile edge;
Grade 2: small number of cracks, sapwood, wormholes at face side are allowed; the inclination angle of the wood fibers to the tile edge shall not exceed 30%