Effect Of Low Relative Humidity On Properties Of Structural Lumber Products

Wood used in industrial settings, and in some arid parts of the United States, may be subjected to very low relative humidity (RH). Analytical models available for predicting the effect of moisture content (MC) on the properties of solid-sawn lumber imply significant strength loss at very low MC. However, these models are generally valid only for MC above about 10%. The objective of this study was to evaluate the flexural and tensile properties of standard 38- by 89-mm (nominal 2- by 4-in.) dimension lumber equilibrated at 15% RH compared with lumber at 65% RH. Testing was done on solid-sawn lumber, laminated veneer lumber (LVL), and laminated strand lumber (LSL). The results of this study indicate that modulus of elasticity (MOE) in…