Defects and Blemishes

A defect in lumber is any flaw that tends to affect the strength, durability, or utility value of the lumber. A blemish is a flaw that mars only the appearance of lumber. A blemish that affects the utility value of lumber, such as a tight knot that mars the appearance of lumber intended for fine cabinet work, is also considered a defect. Various flaws apparent in lumber are listed in Table 2.