The choice of floorboard depends on the functionality and purpose of the floor itself. For example, for arranging a black floor, a board about 15% is perfect. When choosing such a board, pay special attention to the lack of mechanical damage and warping of the material. The number of knots does not play an important role, the main thing is that they are not rotten. If the board is used as a finish finishing coating, then the moisture content of the board should be no more than 10%. When choosing, pay attention to the accuracy of the geometric shape of individual boards and the number of knots, which should be few in the finishing board for the floor. The most popular thickness of the boards is 20-22 mm, but if a significant load is provided on the floor, then you can use boards with a larger thickness.