While all our domestic lumber species here at J Gibson McIlvain Lumber are graded according to NHLA (National Hardwood Lumber Association) guidelines, Walnut is, in some ways, in a league of its own. Many customers don’t understand the unique distinctions that set Walnut apart from other North American species.
The first step toward better appreciating the unique beauties of Walnut lumber is to compare and contrast the NHLA guidelines for Walnut with those of other domestic lumber species.
First and Seconds (FAS) Walnut
For most species, those boards allowed into this elite grouping must meet the highest set of expectations, as set forth by the NHLA, including the following:
• Minimum board size is 6” by 8’.
• Minimum clear cutting size is 3” by 7’ or 4” by 5’.
• 83.3% of the board is defect free, on both faces.
However, for Walnut, those guidelines are appended in order to allow more boards into this grading category. The differences are as follows:
• Minimum board size is 5” by 6’ (as long as 80% of the pack yields 8’ and longer)
• Pieces measuring 5” by 6-7’ are permitted some wane along the edges, as well as splits 6” or shorter on 1 end, and 1 defect.
• Pieces that are 8” or wider are allowed 2 defects.
Select Walnut
This grading category is similar to FAS, except that only one face is required to meet the grading requirements. As such, for most species the general qualifications for boards to be considered “Select” must meet these criteria:
• Minimum board size is 4” by 6’.
• Minimum clear cutting size is 3” by 7’ or 4” by 5’ (the same as for FAS, but only on one side).
• 83.3% of the board is clear and defect free on 1 face (with the other face meeting qualifications for #2 Common grade).
For Walnut, the above qualifications must be met, with one alteration:
• Minimum clear cutting size is 4″ by 3′ or 3″ by 6′.
#1 Common Walnut
Less in demand, Common grade lumber still provides a good amount of usable lumber on each board. For jobs that allow you to work with or around knots, Common lumber is ideal. #1 Common lumber for most species must meet these standards:
• Minimum board size is 3” by 4’.
• Minimum clear cutting size is 3” by 3’ or 4” by 2’.
• 66.6% of both faces must be clear.
Walnut lumber must meet those same guidelines, with this one exception:
• Minimum clear cutting size is 3″ by 2′.
#2 Common Walnut
To meet the qualifications for #2 Common Grade, a board of most species must be described as follows:
• Minimum board size is 3” by 4’.
• Minimum clear cutting size is 3” by 2’.
• 50% of the board is clear on the better face.
Hardwood flooring manufacturers often use common grades, because narrow boards provide stability, and only one face is seen.
With Walnut, #2 Common isn’t much different with one exception:
• Minimum clear cutting is 2″, with no length restriction.
The minimal amount of clear cutting makes this grade of Walnut suitable only for projects requiring very small pieces or rustic applications.
Continue reading with Part 2.
