How to test to see if a wall is straight for laminate flooring installation?
One way to test a wall for straightness is to stretch a string from corner to corner. A good practice when doing this is to space the string out in the corners by the thickness of a board. Then the gap between the string and wall all along can be checked to see how even the wall is. The gap can even be checked with another piece of board that has the same thickness as that used in the corners.