Understanding lumber grades will help ensure you meet design expectations. Lumber grades are divided into three basic categories: structural framing products, appearance products and industrial products.
Structural framing products are graded for their strength and other physical properties, as opposed to appearance products, which are graded for their aesthetic properties. Industrial products include a combination of both structural and non-structural properties.
The American Lumber Standard Committee lumber program, operating under the Board of Review, currently has 31 accredited independent third-party agencies headquartered throughout the United States and Canada. Each of these agencies operates under one or more of the seven sets of grading rules certified by the Board of Review as conforming to the American Softwood Lumber Standard PS 20.
Learn more about structural lumber grades with these resources.
Douglas Fir
Western Wood Products Association:
Products Graded for Structural Applications
Eastern White Pine
Northeastern Lumber Manufacturers Association: Standard Grading Rules for Northeastern Lumber
Hem Fir
Western Wood Products Association:
Ponderosa Pine
Western Wood Products Association:
Southern Pine
Southern Pine Inspection Bureau:
Southern Pine eLearning Course
Southern Forest Products Association: Southern Pine Grade Descriptions
Spruce-Pine-Fir
West Coast Lumber Inspection Bureau
Interpretations for the National Grading Rules for Dimension Lumber
WCLIB Standard No. 17 Grading Rules for West Coast Lumber 2004