After the lumber is sawed into whatever sizes are desired, the wood is dried. Lumber is dried for several purposes. This means that the moisture content is less than 19 percent. MC15 means that the moisture content is less than 15 percent. Species and species groups.
Dimension lumber is the principal stress-graded lumber product available at most retail lumberyards.
This lumber probably will be used where strength, stiffness and size uniformity are important. Floor joists, ceiling and roof rafters, and studs are common examples. Although there are many sizes and species of material produced, not every lumberyard stocks every item. A lumberyard usually will have only the most commonly requested items in stock in a few species groups. Hem-fir stands for western hemlock and true firs.