Walnut is America’s premium hardwood … popular for many high-end architectural applications. This gorgeous example is an engineered floor with a thermally-treated wear layer … this process unifies the color variation normally found in a “character” grade, and also simplifies spot-repair of scratches. The factory finish is a hard wax oil, providing a low-gloss/matte luster. It’s suitable for above-grade and below grade installations, and additionally over water-based radiant heat systems. It can be nailed, glued or floated. Occasional knots are allowed in this grade. The finish wear-through warranty is 30 years for residential applications/5 years commercial. The structural warranty is lifetime.