The black walnut is a deciduous tree that is indigenous to North America and is found in the eastern United States. Black walnut trees grow from Vermont to the Great Plains, and south to Louisiana and Texas. They thrive in drier soils and are often found above streams and brooks. The highest quality black walnut trees are found in and around the Ohio region of the United States. The black walnut tree can grow to a height of 120 feet and usually reaches maturity between 100-150 years. Because of its dark color and working characteristics, it is highly coveted by woodworkers and is used for flooring, furniture, and cabinets. Let’s look at the characteristics of black walnut and why it is such a good choice for hardwood flooring.
Black walnut trees have a unique dark color. The heartwood, the center of the tree, ranges in color from dark chocolate brown to light greyish brown. The sapwood, the outer part of the tree trunk where the tree’s nutrients are located, is white to yellowish, gray, or tan. Because of its unique color, there is usually no need to stain or finish black walnut flooring. Most times only a clear coat sealer is applied to protect the wood and allow for the natural color to be displayed.
Unlike other types of wood, the color of black walnut can lighten over time with sunlight being the most common cause of this color change. A proper sealer can help minimize the color lightening effect. Sometimes an oil finish is used to enhance the color of black walnut considering oil saturates the grain and brings out a slight honey tint in the wood.
Black walnut is a dense wood that is also very resistant to decay. On the Janka hardness test, a test used by placing a steel ball on the wood where force is applied until the ball is embedded halfway in the wood, black walnut falls between harder wood like black locust and softer woods such as chestnut. The force of the Janka test is measured in pounds-force (lbf) with Black Walnut rating at 1,010 Janka. Its Janka ranking and resistance to decay makes black walnut a good choice for hardwood flooring.
The grain of black walnut is usually straight but may have slight curls or waves. Black walnut is usually recognized by its knots, crotches, and burls. Its unique combination of color and grain make it easily recognizable.
Black walnut’s stability makes it a perfect fit for hardwood flooring. It is usually available in thicknesses ranging from ½” to 7/8”, and 2 ¼” to 12” wide. It's available in several lengths up to 10 feet. Black walnut has strength properties, shock resistance, and dimensional stability. It has a dimensional stability factor of 5.5% radial and 7.8% tangential. It only shrinks or swells up to 7.8% of its width from when it is cut to when it is dried. It comes unfinished and finished and is available in our engineered wood flooring collection, Novara.
Daily maintenance of black walnut is similar to the maintenance required for other hardwood flooring types. It’s important to not let moisture damage the wood. Unlike other hardwoods, black walnut can be difficult to sand. If you choose to refinish your black walnut floor, you must sand it with a diagonal stroke and it is recommended that you use a multi-disc or hard plate sander.