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 nonstructural 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.