When the Framing Shrinks Detail for wood shrinkage, and avoid callbacks for cracked plaster, stuck doors, and popped nails. by Henry Spies Wood is the most common building material in the U.S., but it is also one of the most unstable. Wood shrinkage (and expansion) has been the bane of builders since Noah. Basically, wood shrinks dimensionally as it loses moisture. Most of the shrinkage is across the grain, but there is some along the grain as well. The amount of shrinkage varies with the species of wood and with the specific moisture-content range. For instance, as Douglas fir dries, the cells close and lock the opening, making it difficult for moisture to be reabsorbed. At the other end