The North American Softwood Lumber Grading Rules (NLGA) are a set of standards that dictate the classification and grading of softwood lumber produced in North America. The rules were first established in 1923 and have since been revised periodically to reflect changes in the lumber industry.
The NLGA grading rules are used by lumber inspectors to determine the quality and value of softwood lumber, based on factors such as the size, appearance, and structural properties of the wood. The grading system is divided into several grades, including Select Structural, #1, #2, and #3, with additional designations for specialized applications such as boards for sheathing and decking.
The NLGA grading rules are recognized by the United States and Canadian governments, and compliance with these standards is required for softwood
lumber to be sold in these countries. The rules are also used in international trade, as many countries have adopted them as a basis for softwood lumber grading.
Overall, the NLGA grading rules help ensure that softwood lumber is consistently graded and accurately priced, providing a level of transparency and trust in the lumber market.