Even in the modern construction world, dimensional lumber is still one of the industry’s most common structural components. And given that wood is a renewable material, that situation isn’t going to change anytime soon. As one of the world’s most sustainable building products, lumber, including framing studs, roofing trusses, flooring systems and solid timbers, is found throughout residential, commercial, industrial, institutional and recreational construction projects worldwide.

Machine Stress Rating

Machine stress-rated and machine-evaluated lumber is readily available for building needs where great strength is critical, such as truss rafters, laminating stock, I-beams and web joints. Machine grading measures a characteristic like stiffness or density that correlates with the structural properties of interest, such as bending strength. The result is a more precise understanding of the strength of each piece of lumber than is possible with visually grading.

Kiln Drying

The moisture content of freshly sawn timber is higher than desired for manufacture into raw materials, so kiln drying is usually employed before lumber is shipped to users. The process increases the wood’s structural integrity, reduces swelling and/or shrinkage and enhances its appearance and workability. Virtually all lumber is kiln-dried to moisture content of 19% or less.

Delivering Consistent Quality

Wood is an organic, natural resource. Therefore, lumber varies in appearance, natural characteristics and quality. Canada employs standardized grading rules among mills manufacturing similar woods for the industry-wide purpose of ensuring uniform quality at several different levels.

The National Lumber Grades Authority (NLGA) is responsible for writing, interpreting and maintaining Canadian lumber grading rules and standards. The Canadian Lumber Standards Accreditation Board (CLSAB) monitors the quality of Canada’s lumber grading and identification system.