Wood - Lumber Stress Grade & Design

Course Summary

This course briefly discusses the U.S. Department of Commerce American Softwood Lumber Standard PS20 (1994) sorting criteria for two stress-grading methods, and the philosophy of how properties for engineering design are derived. The derived properties are then used in one of two design formats: (a) the load and resistance factor design (LRFD), which is based on a reference strength at the 5th percentile 5-min bending stress (AF&PA 1996), or (b) the allowable stress design (ASD), which is based on a design stress at the lower 5th percentile 10-year bending stress. The properties depend on the particular sorting criteria and on additional factors that are independent of the sorting criteria.

Learning Objectives

• Responsibilities and Standards for Stress Grading
• National Grading Rule
• Visually Graded Structural Lumber
• Visual Sorting Criteria
• Procedures for Deriving Design Properties
• Machine-Graded Structural Lumber
• Machine Sorting Criteria
• Procedures for Deriving Design Properties
• Quality Control
• Adjustment of Properties for Design Use
• Shrinkage
• Moisture Adjustments
• Treatment Effects
• Temperature Effects

Course Author

US Forest Service

Review the quiz before studying the course.

Certificate of completion of the course

This course comes with a multiple-choice quiz. You can view the quiz and take the quiz if you are logged in your account. You can take the quiz for this online PDH course as many times until passed. The passing grade is 70% and above. After you pass the quiz simply follow the page, to pay for the course and print your certificate instantly. A copy of the certificate and receipt for this course will always be in your account.

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This online PDH course can also be used as a continuing education course for the following.

Architects

Civil Engineering

Structural Engineering

Mechanical Engineering

Contractors