I am currently redoing floorboards in my bedroom approx size 2.2 by 3.2m. Some of the joists have twisted so there is some work to be done on getting them level for the flooring. Any tips on how to find the high point and to check a level over the long run as the joists are running parallel to the short edge. If i had something approx 3 meters with a straight edge i would be able to tell which joists are higher or lower. Any tips?