Grades and Applications

Timber grades fall into three basic classifications: 1) appearance grades that address aesthetic qualities rather than strength properties; 2) industrial use and remanufacturing grades; and 3) structural grades for construction purposes. All species are available in a range of grades that identify each product for its intended end use. The symbols below which appear in the code bar to the right of each wood photograph identify the different categories of grades used for each species.

Appearance Grades

Timber products graded for appearance have many applications where aesthetic appeal is more important than strength. Any load-carrying capacity in appearance products is not considered in assigning the grades, except in a specific category for stress-rated boards. All western species are available in appearance grades and, as such, are generally shipped as individual species; however, various combinations of species may be used to simplify purchasing. Western species include varied textures and grain patterns and are available in a full range of products from high, clear, premium grades to the most economical. Some naturally durable species resist rot and weather to a natural, silver-gray patina when used in exterior installations. Applications for appearance grades include panelling, cladding, shelving, flooring, furniture and decorative installations.

Remanufacturing and Industrial Grades

The timber products in this category are milled from a variety of species but primarily Douglas fir, Hem-Fir, and the Ponderosa and Sugar pines. Timber in the Factory & Shop remanufacturing grades is intended to be re-cut into small specific sizes for use in the manufacturing of other products. These species are easily machined, have good nail and screw-holding properties, and finish well. Remanufacturing applications include cabinets, fine furniture, windows, doors, flooring, moulding, specialty items, pencils and woodenware. Applications for industrial grades include foundry patterns, crates, boxes, pallets, stakes and construction forms.

Structural Grades

Douglas fir-Larch, Hem-Fir and Spruce-Pine-Fir^S species combinations are manufactured in light framing, structural-light framing, and structural joist and plank grades and sizes. In the U.S., these products, nominal sizes 2" to 4" (38 x 89 mm) thick by 2" (38 mm) and wider, are referred to as dimension lumber. Larger sizes are known as heavy timbers. Beams & Stringers are 5" (114 mm) and thicker with width more than 2" (51mm) greater than thickness. Posts & Timbers are 5" x 5" (114 x 114 mm) and larger with width not more than 2" (51 mm) greater than thickness. All of these structural grades and sizes have assigned engineering values. Common applications include framing, engineered systems, laminated beams, concrete forming, scaffolding, beams, columns, etc.

Special structural grades and sizes, specific to the needs of destination countries, are manufactured and shipped by U.S. mills under the supervision of RIS, PLIB, WCLIB and WWPA. Products may be shipped unseasoned or kiln dried. A variety of international products commonly referred to as Baby Squares, J-Grade and Scantlings are available through buyer-seller agreements.