A Check is a separation of the wood normally occurring across or through the rings of annual growth and usually a result of seasoning.
Characteristics 102: Fiber Failures
In Characteristics 102 you will be learning about the various kinds of fiber failures that can occur in lumber.
102: Surface Checks
102: Star Check
102: Through Check
102: Check Sizes
102: Edge Break
Splits are defined as a separation of the wood through the piece to the opposite surface or to an adjoining surface due to the tearing apart of the wood cells. Splits are identified by their sizes. [Standard Grading Rules for Northeastern Lumber para. 742.0]
Very Short – is equal in length to 1/2 the width of the piece
Short – is equal in length to the width of the piece and in no case exceeds 1/6 the length.
Medium – is equal in length to twice the width of the piece and in no case exceeds 1/6 the length.
Long – is longer than a medium split.
Shake is a lengthwise separation of the wood which occurs between or through the rings of an annual growth (Standard Grading Rules for Northeastern Lumber 740.0).
Light Shake – not over 1/32″ wide
Medium Shake – not over 1/8″ wide
Surface Shake – occurs on only one surface of a piece
Through Shake – extends from one surface of a piece to the opposite or to an adjoining surface (shown)