Structural Finger-Jointing Criteria and Performance

Structural end joints are required for the production of glued laminated timbers used in engineered construction. Prior to 1962, the laminating industry used plain scarf joints meeting a strength ratio performance criterion. In 1962 the end joint qualification criterion was changed to a specific performance criterion and adopted by Commercial Standards CS 253-63. Finger joints meeting this new criterion were first commercialized in 1962 and the industry is converting to this more economical process. Research and development were required to optimize the finger joint and production equipment leading to commercialization. In addition to being more economical, the finger joint is less variable than plain scarfed joints and therefore is preferred for structural as well as nonstructural uses.