In North America, walnut flooring is made from logs of the American Black Walnut tree, or Jaglans nigra. It is also known as the Burbank Walnut, the Virginia Walnut, or as Gunwood, because the wood was traditionally used for gun stocks. The species is native to eastern North America, from Ontario, Canada south to the central United States. Its beautiful dark color makes it an attractive type of hardwood flooring.
Walnut varies in color naturally. The tree's heartwood is a deep chocolate brown with purple overtones. Younger rings have a lighter color, and the sapwood is nearly white. The highest grades of walnut flooring are cut from heartwood. The color will continue to darken naturally as the floor ages.
Walnut flooring is usually air-dried instead of kiln-dried, because the color shows up better that way. Some manufacturers steam boards to darken the pale color of the sapwood. Since the wood has a naturally rich color, it does not need to be stained. A protective finish is applied before walnut flooring is installed.
Walnut has a straight, even grain for the most part. Burl patterns may appear where a limb grew out from the trunk. This beautiful patterned wood is usually reserved for making furniture, but it can sometimes be found in walnut flooring.
Walnut is a strong wood with high dimensional stability. It is less sensitive to variation in heat and humidity than many other woods. Walnut flooring can even be installed over radiant heating systems.
Walnut has a Janka rating of 1010, meaning that it is somewhat softer than oak. The Janka scale is a way to compare the hardness of various kinds of wood. Of woods commonly used for flooring, the hardest wood is Brazilian ebony, and the softest is pine.
Walnut is used in all types of hardwood flooring installations. It is in high demand for parquet flooring because its naturally dark color provides a wonderful contrast to pale wood. It can be purchased as strip flooring, with boards about two and one-quarter inches (5.7 cm) wide; as plank flooring, with uniformly sized boards a little wider than three inches (7.6 cm), or as wide plank flooring, in varying widths.
Walnut flooring is also available as a veneer over a less expensive base. Vinyl flooring that closely imitates the look of walnut is also available. These choice give the appearance of a walnut floor, but at a reduced cost.