Definitions may include
- Softwood Lumber:
- Stress-graded (lumber graded for structural strength and durability)
- Nonstress-graded (lumber graded based on both appearance and strength)
- Appearance-graded (lumber graded primarily for visual quality)
- Hardwood Lumber:
- Firsts and Seconds (the highest grade, characterized by the fewest defects and a high percentage of clear lumber)
- Selects (a grade between FAS and Number 1 Common, often used for furniture and cabinet making)
- Number 1 Common (a commonly used grade for cabinets, millwork, and general construction)
- Number 2 Common (a lower grade often used for less critical applications or for cutting into smaller pieces)
- Number 3 Common (the lowest grade, often used for less demanding applications or for basic construction)
- Defects:
- Checks (cracks that occur along the wood's growth rings, often due to rapid drying)
- Knots (natural imperfections formed where branches have grown on a tree)
- Wane (missing wood or an untrimmed edge along the side or corner of a board)
- Shakes (separations that occur between the wood's growth rings, often before the tree is felled).
Process/Skill Questions:
- Why is lumber grading important?
- What are the differences between hardwood grading and softwood grading?
- How much training is required before becoming a lumber grader?