Nlga Lumber Grading Manual !FREE!
Nlga Lumber Grading Manual ->>> https://blltly.com/2trTrd
Canadian dimension lumber is manufactured in accordance with CSA O141 Softwood Lumber and must conform to the requirements of the Canadian and US lumber grading rules. Each piece of dimension lumber is inspected to determine its grade and a stamp is applied indicating the assigned grade, the mill identification number, a green (S-Grn) or dry (S-Dry) moisture content at time of surfacing, the species or species group, the grading authority having jurisdiction over the mill of origin, and the grading rule used, where applicable.
To ensure this uniform quality of dimension lumber, Canadian mills are required to have each piece of lumber graded by lumber graders who are approved by an accredited grading agency. Grading agencies are accredited by the CLSAB.
The lumber grader is an integral part of the lumber manufacturing process. Using established correlations between appearance and strength, lumber graders are trained to assign a strength grade to dimensional lumber based on the presence or absence of certain natural characteristics. Examples of such characteristics include; the presence of wane (bark remnant on the outer edge), size and location of knots, the slope of the grain relative to the long axis and the size of shakes, splits and checks. Other characteristics are limited by the grading rules for appearance reasons only. Some of these include sap and heart stain, torn grain and planer skips.
There are two groups of people that want to understand how dimension lumber is graded, those using it and those producing it. The producers of dimension lumber will be very knowledgeable of how the lumber is graded and have access to training methods that the lay person does not. For many of those using framing lumber, the grading process and application of the rules remains a mystery.
Learning to grade dimension lumber on the production line can be a time consuming and challenging task. Traditionally, grader training takes place at the mill. Potential candidates are sometimes screened based upon their level of interest, ability to deal with simple math, and the willingness and ability to study and memorize the rules. In the US, mills are primarily responsible for developing graders with help provided by the Inspection Agency staff during lumber grade audits or specially scheduled training visits. This type of training has not been standardized. In Canada, the potential grader may be required to attend off site grading classes which are provided by the regional Grading Agencies to prepare students and to award grading tickets that signify successful completion of the training course. In this way, training can be delivered in a more organized fashion and tends to be more efficient for the trainee and the instructor, but it also introduces extra expenses in term of travel time and lodging. These courses are usually only available to producing mill employees.
The Southern Pine Inspection Bureau has recently introduced a series of online courses originally designed to enhance and speed up the traditional training methods used for dimension lumber graders in all producing regions of the US and Canada. With these SPIB eLearning courses you can obtain all of the essential training materials in a very systematic manner; starting with the fundamental terminology, the definitions and illustrations of the defects, the tools for understanding fractions and how they apply to the edges and width of lumber, how to read a tape measure, how to measure different shapes of knots, how to apply each grade rule, and even how to judge the size of knots without measuring. These courses make it efficient for anyone to learn and understand grading concepts and all the grade rules for Softwood Dimension Lumber.
"Green" unseasoned lumber fresh from the mill is labeled either air-dried (AD) or surface-green (S-GRN). Its moisture content of 19 percent or more makes it inexpensive, but it can move unpredictably as it shrinks and dries. You'll get less movement