Wood Grades / Cuts
To coincide with the unique characteristics of wood species, the appearance of a wood floor is greatly determined by the grade and cut of the wood.
The grading system is based on the amount of natural characteristics (knot holes, mineral streaks, tone variation, etc.) present in a particular piece of lumber. The grading scale ranges from a Clear Grade uniform lumber with the least amount of variation to a Rustic Grade that has fascinating array of character and variation.
The next determining factor in the appearance and performance of your wood floors is the cut. Depending on the angle and process in which the wood is cut, grain variation can differ drastically. The types of cuts are broken down into four categories: Live/Flat Sawn, Plain Sawn, Quarter Sawn, and Rift Sawn.
Plain Sawn: The most common way lumber is cut for wood flooring. In this process, wood is cut parallel to the annular growth rings of the log which reveals the tangential grain. This tangential grain is what produces the beautiful “cathedral arch” pattern on the face of the boards.
Quarter Sawn: This cut of wood produces a beautiful, consistent, linear grain pattern. The wood is cut radially and the annular growth rings intersect the board’s face at a 60 to 90 degree angle. A unique characteristic to quarter sawn wood is the presence of ray flecks. This occurs when cuts are made across the wood’s ray cells and it produces the shimmering flake appearance throughout the board.
Rift Sawn: This cut of wood is done within the same process as quarter sawn but the boards come from the outer part of the log. The annular rings cross the board face at a 30 to 60 degree angle with 45 degrees being ideal. This produces the tightest grain formation and results in the absence of ray flecks. Rift sawn wood can be bundled/produced as either a compliment to quarter sawn wood or it can be cut specifically as rift sawn.
Live Sawn/Flat Sawn: The most efficient and least labor intensive way that lumber is cut. This style of cutting leads to the most variation of grain patterns as it is a combination of Plain, Quarter, and Rift patterns.
The following video from the Frank Miller Lumber Co. provides a great explanation of the Quarter Sawing process that produces both Rift and Quartered boards.