Kiln-dried lumber is used for many purposes, but the variety of trees that can be dried in a kiln can make it difficult to choose the right type of lumber. Kiln drying allows operators to adjust the moisture content of wood, so you should choose wood that is dry enough for your needs. Both softwood and hardwood can be used for kiln-dried lumber, and choosing between the two often is important. You also are likely to need to choose a specific type of wood. The chosen kiln-dried lumber then should be usable for your project.
One of the benefits of kiln-dried lumber is that the kiln can be set to varying levels to control the amount of moisture that is removed from the wood. This means the wood can be made very dry or just slightly dry, and both serve different purposes. You should decide whether you want a wood with more bend and moisture or a drier wood that is sturdier but more likely to splinter and crack from use.
Softwood and hardwood come from different species of trees. Despite their names being misnomers, because some softwoods are hard and some hardwoods are soft, hardwoods often are harder and more durable. This does not apply to softer hardwoods such as balsa, but it does apply for most of the other hardwoods. Softwoods are commonly used and, thus, may be cheaper; there also are many softwoods that are hard and durable enough for construction and other projects.
After choosing between hardwood and softwood, you will need to choose a specific type of kiln-dried lumber. Hardness often is important, but there are other aspects to look at, too. For example, you may need a certain color of wood, light or heavy wood, or a wood that has specific properties, such as rot resistance and weathering resistance.
Another aspect to consider when choosing kiln-dried lumber is your specific project. Some kiln-dried wood sellers can dry wood to your exact specifications for your project and, if you are dealing with the kiln operators directly, this could be useful. The lumber also may be cut in certain shapes to make it easier for your project, such as planks for general construction, fencing materials and shapes or decking wood. Most kiln-dried wood is in plank form, but not all of it.