MOISTURE-CONTENT VARIATION IN WHITE-PINE LUMBER DRIED AT 7 NORTHEASTERN MILLS

Sample moisture content (MC) distributions from recently dried eastern white pine lumber were measured at seven of the largest mills in the northeastern United States. In total, about 3,500 boards from 14 kiln charges were measured. Where possible, charges from two different kilns were sampled at each mill. The results show that substantial MC variation exists within a given charge of dried lumber. On average, about 22 percent of the lumber from a kiln charge was underdried and 39 percent was overdried. Only 39 percent of the sampled lumber was within the targeted MC range. In most cases, substantial MC variation was also noted between kilns at each mill. The results also suggest that a more tightly controlled equalization period under less severe drying conditions would be helpful in reducing the amount of variation. The between-kiln variation suggests that more detailed maintenance checks and calibrations or more attention to stacking and handling practices are needed.