Learn About Lumber
Making the Grade
Construction lumber is different from non-wood products in that it is "natural" and subject to characteristics such as knots, twists, and wane (missing wood on the edge). There are a number of factors that have a bearing on the quality of wood products. The first one is grade. Grading is done at the sawmill, based on standards that have been established by lumber trade associations in cooperation with the federal government.
Many of our lumber customers want a defect-free appearance, since that's how they define quality. The challenge for retailers is that many of their customers associate "quality" with "good appearance." We are passing those appearance demands along to our suppliers.
Our lumber buyers are working directly with the mills on standards and specifications to improve the appearance of the wood we buy. Due to our continual efforts, we now have "four square" lumber, meaning all four sides are square, with little or no missing wood on the corners. The material is still officially grade stamped for its structural value, but it exceeds the rules on appearance (being square and straight).
Not all lumber will be the highest possible quality, because there are those price conscious consumers who are looking for the least expensive product that will still do the job. This is why we may carry lesser grades in certain items.
Did You Know?
Lumber is graded for allowable defects – how bad it looks, not how good it looks. This is true whether the wood is being graded for appearance or strength.
In general, most boards (1-bys) are graded based on appearance and most dimension lumber (2-bys, 4-bys, 6-bys) are graded for strength. An illustrated list of the most common defects found in lumber is presented below:
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| Honeycomb |
Seasoning Check |
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| Shake |
Spike Knot |
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| Split |
Unsound Knot |
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| Unsound Wood |
Wane |
