Spruce lumber is made from one of the more than 30 varieties of tree in the genus Picea. A strong and relatively light wood, spruce lumber has many uses in a variety of industries. It is perfectly possible to have a box, a piano, and a full-sized boat all made from spruce.
Spruce lumber is made by refining raw spruce logs into more uniform and usable forms. Generally, spruce logs arrive at a lumber factory or mill just after felling, and still retain their original shape. Most commercial lumber is refined by machine, using a variety of high powered saws and shapers to create uniform boards. Boards may be treated with chemicals to be made more durable or fire-resistant. Spruce is either sold by the mill or shipped to lumber suppliers for public sale.
Most spruce lumber is light in color, with a even and fine grain to the wood. Even though there are many different types of spruce trees, many varieties will appear nearly identical when milled into lumber. Spruce is noted for having a very high strength-to-weight proportion, making it ideal for situations where the wood required is both lightweight and load-bearing.
One of the most interesting uses of spruce lumber is in the building of wooden airplanes. The sitka spruce tree in particularly is noted for airplane use, thanks to its fine grain, light weight, and wide availability. Some lumber mills set premium spruce wood aside specifically for airplane use, since only a small amount of lumber will have the requisite strength to withstand aircraft forces and pressures. Ironically, one of the most famous wooden airplanes in history, Howard Hughes' “Spruce Goose” relied heavily on birch wood, having only a few spruce parts.
Sitka spruce is also a frequent part of boat building, particularly when the primary concern is keeping weight low. It is important to note that very few varieties are good for outdoor use at all, since many types of spruce does not stand up well to weathering and is subject to a relatively fast decay. Sitka spruce is used to build masts and spars, thanks to the tree's durability and natural height.
For furniture, crates, barrels, and musical instruments, some spruce lumber may be ideal. Common types of spruce used for indoor furnishings include Eastern spruce, red spruce, black spruce, and Engelmann spruce. These types of lumber are also frequently used for house construction as interior timbers, but are generally not placed in areas that would expose them directly to the elements.