Predicting the Effect of Moisture Content on the Flexural Properties of Southern Pine Dimension Lumber


  • David W. Green
  • Carol L. Link
  • A. Louis DeBonis
  • Thomas E. McLain


Analytical models, mechanical properties, bending, moisture content, dimension lumber


Current procedures for adjusting lumber properties for changes in moisture content are based on trends observed with the mean properties. This study was initiated to develop analytical procedures for adjusting the flexural properties of 2-inch-thick southern pine dimension lumber applicable to all grades and sizes as well as all levels of the cumulative frequency distribution. Equations are derived for adjusting modulus of rupture (MOR), modulus of elasticity (MOE), moment capacity (RS), and flexural stiffness (EI) for changes in moisture content. The best of these equations are significantly more accurate than current procedures for adjusting strength properties (MOR and RS). Because MOE and EI are less affected by changes in moisture content, most of the equations, including the current American Society for Testing and Materials procedure, work well for these properties.


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Research Contributions