Stack of lumber having low resistance to airflow therethrough and associated method

A stack of lumber that can be efficiently dried includes a plurality of layers of lumber that are arranged one above the other and extend longitudinally and laterally. Each layer of lumber includes a first edge that extends in the longitudinal direction and at least partially defines a side of the stack of lumber. Many of the first edges of adjacent layers of lumber are laterally spaced apart by at least a predetermined separation distance so that the first edges define a staggered arrangement. Also, the layers of lumber that are adjacent are vertically spaced apart from one another so that each of the adjacent layers of lumber define a laterally extending passage therebetween. Each of the passages includes an inlet and an opposed outlet defined between two of the adjacent first edges that are vertically and laterally spaced apart from one another. The flow of air through the stack of lumber is distributed through the passages such that within each passage oppositely oriented boundary layers are formed. Each of those boundary layers includes a generally planar portion, which is proximate to the outlet of the respective passage, and a protruding portion, which is proximate to an inlet of the respective passage. For each passage, a peak of one of the protruding portions is downstream from a peak of the other of the protruding portions by at least the predetermined separation distance so as to reduce the restriction to airflow therethrough and thereby increase the size of the effective opening through which air can enter the passage.