Wood on the Move

 

Wood Shrinkage II

How wood shrinks Unlike a dissolving sugar cube, a block of wood doesn't behave the same in all directions as it shrinks. As shown in the illustration, wood shrinks most in the direction of the annual growth rings (tangentially). It shrinks about half that much across the growth rings (radially). And shrinkage with the grain (longitudinal) is minimal. The result: Combined radial and tangential shrinkage distorts the shape of any piece of wood because of the difference in the two shrinkage rates and the way the annual rings curve. A number of variables affect how and to what degree wood shrinks, But in general, the denser the wood, the more it shrinks.