Often, dimension lumber users complain about the quality of the lumber. Despite the package bearing a similar grade mark, the appearance might be worse or better. Despite the correct gradation of the lumber, certain factors influence the overall appearance in specific grades. The primary reason for writing grade rules was for controlling the strength within single gradations. However, it involved only limited considerations that were related to the appearance of the lumber.

Rules for Grading

The first consideration are always grading rules, where the National Grading Rule (NGR) describes possible worst-case scenarios related to every characteristic and defect of lumber allowed within each grade. This leads to variations in individual pieces appearance within grades. Grading rules will limit defects related to every piece, but not the pieces themselves.

For example, dense, straight, very good lumber pieces containing a single edge and small knots will fail to get the number one grade. Similarly, less dense lumber with maximum allowable knots, wane, warp or skip also get the number two grade and some pieces appear different from others for this reason. Number two slot in grading goes to wane with maximum 1/2 face, 2/3 edge for maximum 1/4 of overall length. This suggests a good wane. Such generous allowance for wane is because it does not reduce published stress ratings for the number 2 slot in grade rules. Each piece in this slot may not contain the allowable maximum wane. The variation related to the pieces with same-grade wane can be much large.

Skip also influences the appearance of lumber. This refers to surface areas that are not ideal for planning because of the presence of scant width or thickness. This makes for poor appearances that nevertheless will have minimal effect on the usability and strength. Some over-drying and tolerances for tight sizes will lead to the skip. Focus of the mills on recovery will lead to reduction in rough sizes of lumber. Sawing variances that are too high lead to increased frequency of skip dressing.

When it comes to lumber marketability, the major driving force is customer satisfaction. Treated dimension lumber finds wide use in outdoor projects. It is frequently sold in big-box retailers for use by “weekend warriors” and do-it-yourself enthusiasts. For this reason, there is an increasing requirement for graded and produced lumber specifically for appearance’s sake, considerably beyond the perimeter of grading rules. For this reason, producers manufacture lumber better than what rules allow based on market demands and the customer base they cater to.

Quality of raw material

This also affects the appearance of the finished product. There are multiple forms of standing timber where trees stand, and individual trees widely vary in species, growth rate and sizes. Your quality logs will be reflected in finished products as well. Thus, at one end of the spectrum, where poor management of plantations is rife, there will be low-quality logs and the lumber will have natural defects and more knots frequency. With proper management of plantations, the number of natural defects will be less and you would naturally get better quality lumber.

Drying and manufacturing practices

The quality processes at the mills will also affect the lumber appearance within single grades. Poor sawing, bucking, drying, stacking, edging and trimming will influence the finished product’s appearance. Here, the percentage of offsets, wavy dressing, skip, warp and bites will be much higher. Even when the graders remove pieces with undesirable defects, the resulting products will have benefits in comparison to lumber produced by well-maintained facilities that use skilled operators, modern technology and strict quality control. For this reason, manufacturers improve processes constantly to enhance the quality of finished products. They will be better in appearance while conforming to the required set of rules as well.

Producer site grade separations

Appearance of specific grade will also depend upon grade combinations that the manufacturers sort and sell. Upon separation of lower and higher grades, the lumber of lower grade does not appear good. They might be usable and have an acceptable appearance, but they remain substandard, especially when seen with high-grade lumber. When grade separation is not present, the lumber pack will contain pieces with warp, skip, small knots and less wane.

Packaging practices

Lumber appearance will also depend upon the attention and care taken while packaging the goods. Such differences will be visible in lumber of the same quality and grade. In tight and square packages for example, evenly aligned strapping and accurately identified length, size, and grade on placards with an appropriate placement and readability make effective first impressions. Superior quality of lumber will be the pack with bright square ends with evenly placed, legible grade stamps upon every piece. It is interesting to note that when poor packaging of the same pieces is present, there will be a diminished perception of the quality of the dimension lumber.

Florida Lumber stocks a variety of sizes & grades of dimensional lumber that are great for any projects. To get and instant quote on all lumber products in Miami, call us via (305) 635-6412 today!!