Even though variations in the dimensions of a board seem minimal, they are multiplied by the number of rows for boards need to cover the surface area of the flooring. 48 rows of boards 2.5" wide are needed for a 10-foot width of floor (3 m), under ideal conditions, at a temperature of 21 degrees C and a relative humidity rate between 36% and 42%. Boards of red oak have a moisture content rating between 7% and 8%, and their size will remain stable as long as ambient conditions remain unchanged.