Sawlogs are sections of trees that are deemed acceptable for processing in a sawmill. In particular, the sawlog is that portion of the tree that is large enough to be cut into lumber or planking. Many lumber companies actively cultivate trees that are capable of yielding a significant amount of hardwood sawlogs, thus increasing the return on their investment.
In most cases, the dimensions of the tree trunk are the first indicator that a given tree is right for producing a sawlog harvest. Ideally, the trunk is both long and thick enough to produce several planks of a uniform size. In most countries, the standards for the planks created from the sawlog must measure around twelve inches (30.48 centimeters) in diameter, with a one inch (2.54 centimeter) thickness.
There are a couple of other characteristics that help identify if a given section of a tree can be used as a sawlog. One has to do with the presence of knots in the body of the stem or trunk. In general, a sawlog must be relatively free of knots in order to produce the highest grade of planks. In addition, the tree section should be as straight as possible, in order to minimize the amount of waste created during the milling process.
Different types of hardwoods can be harvested for the creation of these types of logs. Oak and elm are two examples. It is also possible to harvest lighter woods for use as well, such as pine and pecan. A heavier sawlog is ideal for making furniture and other wood products that are intended to last for generations. The lighter pecan and pine sawlogs work well for less expensive wooden pieces that are intended to last for several years, but not much beyond that limited time.
While harvesting the sawlog section of each tree is the most financially rewarding part of the lumber industry, the other portions of the tree do not go to waste. Limbs and other sections that are not deemed acceptable for sawlog creation are often reduced to chips and turned into pulpwood and pressed wood products. This allows lumber companies to maximize the profit from each tree harvested, and keep the business financially stable.
Once a sawlog has been processed, the planks resulting from the effort are normally treated with various types of chemicals and sealants. These treatments help to preserve the wood, making it able to withstand changes in temperature, humidity, and climate. This is especially important if the planking is intended for use in the construction of homes and other buildings where the wooden sections would have at least partial exposure to the elements.