Defects
Bow (Lumber Defect)
A warp along the length of a board's face, causing it to curve from end to end like a shallow arc.
In-Depth Explanation
Bow is one of the most common lumber defects and occurs when one face of a board dries faster than the other or when internal stresses release unevenly. A bowed board lies flat side-to-side but curves along its length. Mild bow can often be corrected with a jointer and planer, but severe bow may render the board unusable for long, flat applications. Proper stacking with evenly spaced stickers during drying helps prevent bow. When selecting lumber at the yard, sighting down the edge of the board is the quickest way to detect this defect.
Usage Example
Several of the 10-foot boards had a noticeable bow, so we set them aside for shorter cuts where the warp could be removed.
Related Terms
cup
crown
kiln-dried