Because domestic hardwood is an organic product, you can usually expect to find at least some defects. It’s the rare piece of lumber that has absolutely no defects on it whatsoever. That’s what makes Firsts and Seconds grade lumber so valuable (see Parts 1 & 2 for lumber grading information). The clarity of FAS lumber sets it apart from lower grade lumber. Thankfully, there are plenty of applications that don’t require FAS grade quality lumber. It’s also important to note that what may make a piece of lumber defective for one particular application wouldn’t necessarily make it less useful in a different type of application.
What Elements Would Qualify as Defects in Lumber?
The National Hardwood Lumber Association (NHLA) has come up with a list of different features that they consider to be defects. These defects will detract from the clarity of a lumber board’s face and can end up lowering the grade. Their list of defects would include:
1. Bark Pockets
4. Any Type of Knots
5. Wane or Pith
6. Holes Left by Grubs or Worms
7. Stains Left from Sticks Used During the Drying Process
8. Bird Peck Marks
9. Evidence of Decay or Rot
Any one of these negative features will potentially disrupt the clarity of the board’s face. This will lower the cutting size and, typically, the NHLA grade of that particular board of lumber.
What Features Do Not Qualify as Defects in Lumber?
Not every mark or variation on a piece of lumber would be considered a defect by NHLA standards. The following list of features wouldn’t lower the grade standard or impact the cutting size of a piece of lumber:
1. Gum Streaks
2. Removable Sticker Marks Left Over From the Drying Process
3. Heartwood/Sapwood Transition Areas
5. Mineral Tracks or Streaks
Because the structural integrity of the wood is still intact even when these features are present, they’re not considered a major problem. In fact, in some situations they may even be considered highly desirable depending on the lumber’s designated application. Each individual purchaser will have their own set of preferences when it comes to these elements that aren’t regulated by the NHLA.
This type of variation in what is or is not considered a sought after feature for wood highlights the limitations of the NHLA grading system. In these instances, beauty truly is in the eye of the beholder. Much of the differences of opinion on this topic have to do with different applications favoring different features.
For example, flooring or cabinet makers probably won’t appreciate wood with too many knots, soft spots, and variations in color and grain. They would be more interested in more uniform, stable lumber boards that would be suitable for their intended purposes. But those same idiosyncrasies may be just what a specialty furniture maker is hoping to find to give their woodwork charm and character.
In our final article in this four part series, we’ll take a closer look at some of the limitations of the NHLA grading standards along with some closing thoughts on the topics we’ve already discussed.