Oak is the most popular wood for flooring and the most harvested hardwood in North America. This flooring has a wire-brushed stained 4mm wear layer with a low gloss UV-cured oil finish. It’s suitable for above and below grade installations and additionally over water-based radiant heat systems. It can be nailed, glued or floated. Natural variations and occasional knots are allowed in this grade. Structure and finish have a limited lifetime residential warranty.