I made a small mistake. I am laying 1/2 inch sub floor down over existing boards, gluing and screwing. On one of the sheets I followed the wall in our old house. So now I have a gap between that sheet of plywood and the next row. The gap goes from 0 to about 1/2 inch in 6 or 8 feet. So can I just use floor leveler in this gap? I am putting down 5/8 bamboo flooring, I believe it is 2 and 1/2 or 3 inch wide flooring.