Structural Sawn Timber Quality Requirements

Timber quality is not only related to strength and stiffness. Contractors often are not satisfied with the quality of sawn timber because of its excessive warp (distortion). Current grading practices have been established by the manufacturers, with little consideration of end-users' needs. Lack of communication between timber producers, sellers and end-users contributes to the quality problems of structural sawn timber. The quality of a timber product should be described in a specification of requirements for each individual product. An analysis of timber studs for a typical wall is presented. Acceptance levels are proposed based on interviews with contractors and derived from the requirements set for a typical wall. Field tests are presented which support these proposed tolerance limits. A study of commercially available studs is presented which suggests that it should be possible both technically and economically to produce studs which better fulfill contractors' requirements.