Types of Wood

• Grading begins by identifying the type of wood. Wood is referred to as soft wood or hard wood. Each has its particular uses. Hard wood is for cabinets and furniture, and softwood is used for structural framing and construction purposes. There are always exceptions to these categories. Hardwoods may be used in construction areas where its beautiful surfaces are needed for a visual texture---stairs, fascia, doors. Softwoods can be used as a quick shelving solution or for simple repairs to base boards.
  
  

Components of Grading Lumber

• Grading happens at the sawmill and is conducted by trained and experienced lumber graders. There is a visual component to grading lumber along with a measurement. A grader will look at the lumber, take some measurements, note defects and then grade the board according to the list of possible grades for the type and species of wood. Sometimes an actual grade is stamped onto the board. The stamp is usually found on the raw ends of the lumber.
  
  

Grade Defects

• Defects can vary from knots, decay, bark, splits and warps in the wood. There are ranges of values for defects within each grade. The number of defects, their size and the location are taken into consideration. The warping or twisting in a board is acceptable in varying quantities. Premium hardwoods have fewer defects than what is graded as a "common" board.
  
  

Who Created the Grading Systems?

• Hardwood grading systems were developed by the National Hardwood Lumber Association (NHLA), which was established in 1898. American softwood lumber grading has been developed by the American Lumber Standard Committee Incorporated (ALSC). Standardization of lumber grading allows for a global language to be used during trade. Buyer and seller (national and international) use the same system to communicate a purchase request.
  
  

Grading Lumber

• Although each type of wood has its own grading system, the purpose of grading is the same. The grading process is used to identify the structural integrity of the board. Will the board hold up to the purposes for which it will be bought? By applying a grade to lumber, the buyer is being assured it will provide the structural support or hold up to the constraints of its purpose. Lumber is graded in lots and not per board. This means that while a group of boards are stamped with a particular grade, there may be some boards within the lot that don't fully qualify. They may have ends that meet qualifications but a middle that may be full of knots. This is where the knowledge of the customer comes into play.