Flat Sawn (Plain Sawn)
Flat sawn, also called plain sawn, is the most common method of sawing lumber where the log is cut with parallel passes straight through, producing boards with growth rings at less than 30 degrees to the face. This method maximizes yield and produces the familiar cathedral grain pattern. It is the most economical sawing method.
In-Depth Explanation
Flat-sawing (or through-and-through sawing) involves clamping the log and making a series of parallel cuts from one side to the other. This is the fastest and most material-efficient sawing method, producing the highest yield per log, which is why flat-sawn lumber is the least expensive. The boards in the center of the log show pronounced cathedral grain patterns, while boards near the edges may show more straight grain. The main trade-off is dimensional stability: flat-sawn boards are more prone to cupping across their width because tangential shrinkage (along the growth rings) is roughly twice radial shrinkage (across the rings). For structural framing, flat-sawing is standard and the stability trade-off is irrelevant. For furniture and millwork, flat-sawn stock is perfectly acceptable for many applications, and many people prefer its bold grain character over the more subdued look of quarter or rift-sawn wood.
Usage Example
The lumberyard stocked primarily flat-sawn red oak because it offered the best value, with quarter-sawn available by special order at a 40 percent premium.