Lumber Grading

  • Balsam Fir

    Balsam Fir Grade #2 or Better

  • Pine

    Pine Grade #2 or Better

    Pine Grade # 2 or Better

    Pine Grade #3 Utility

    Pine Grade #3 Utility
  • White Spruce

    White Spruce Grade #2 or Better

    White Spruce Grade # 2 or Better

    White Spruce Grade #3 Utility

    White Spruce Grade #3 Utility

Lumber grading identifies products according to quality, strength and intended use. A lumber grade is a minimum standard describing the characteristics of a piece of lumber as it relates to its end use.

Alberta lumber is graded according to the rules governed by the National Lumber Grades Authority (NLGA). These rules establish strict limits for quality characteristics lumber products must achieve.

Every piece of lumber is inspected and a stamp is applied indicating the assigned grade, the mill of origin, a green or dry moisture content at time of manufacture, the species or species group, and the grading authority having jurisdiction over the mill of origin.

Independent certified lumber graders assess strength characteristics (e.g. grain, knots, checks, decay, splits, etc) and appearance characteristics (e.g. dressing defects, pitch pockets, streaks, stained wood, wane, etc) before grade stamping each piece of lumber. This grade stamp provides consumers with a clear indication of the quality of product they are buying.

Overview of the most common lumber grades in Alberta:

Grading relates to the end use of a piece of lumber, a specific grade requires a certain level of strength and appearance.

Dimension lumber (2-4” thick & 2”or more wide)

Dimension Lumber Usage & General Descriptions Grades
Light Framing (2-4” wide lumber) – for general construction where high strength values are not needed
  • Construction
  • Standard
  • Utility
  • Economy
Structural light framing (2-4” wide lumber) – for applications where higher bending strength ratios are important (e.g. roof trusses)

Select structural

  • No.1
  • No.2
  • No.3
Minimum defects, straight, high visual quality lumber J-Grade
Applications requiring high performance strength characteristics Machine Stress Rated (MSR)
Structural Joists and Planks (5”and wider lumber) – where high strength value is needed (e.g. floor joists)

Select structural

  • No.1
  • No.2
  • No.3
Studs – for applications where strength is important such as vertical use in load bearing walls Stud

To minimize sorting cost grades may be marketed as a group, rather than individually. For example, there is an appearance difference between No.1 and No.2 Canadian dimension lumber but not a strength difference. Therefore the product mix No.2 and better (or #2 & BTR) is commonly used where the appearance characteristics of No.1 grade lumber is not required.

As well, many lumber mills produce customer grades to meet end user specific needs (e.g, Home Centre grade, Appearance grade). These grades vary by mill and are often proprietary, and are not identified here.

Source: AFPA Making the Grade, Lumber Grading Theory Training, Learner’s Workbook