SPF Square Edge Lumber. Every piece meets the highest grading standards for strength and appearance. Dimensional lumber is ideal for a wide range of structural and non-structural applications including framing of houses, barns, sheds, and commercial construction. It can also be used for projects such as furniture and hobbies, and comes in a variety of widths and lengths. Dimensional lumber can also be used in exterior applications as long as it is properly primed and painted or sealed and stained.