Drying Checks

Green (wet) timber shrinks as it dries. It shrinks roughly twice as much along the growth rings as it does across the rings–which is why timber develops drying checks. These checks have almost no effect on the strength of the timber, and engineers take checking into account in their calculations. Aesthetically, we like checks, and think of them like wrinkles in a cotton shirt–it proves the timber is real (and not a box beam). Checking can be minimized to a certain extent. For example: specifying FOHC (Free of Heart Center), selecting a timber species with less shrinkage, slowing the drying process, or purchasing dry timber (reclaimed or radio frequency kiln dried) and orienting the checks in specific timbers so as to be less visible (i.e. toward an outside wall). In the timber industry, a drying check is not the same thing as a split. A check almost always stops at the heart (the center of the tree) of the timber, whereas a split breaks the timber into 2 pieces. © Carolina Timberworks