My stairs are very old and creaky, also the timber that joins them to the wll has had rot so it needs to be replaced, and just for fun the house was flooded in 1950\\\'s and to \\\'help\\\' with the damp left the floor in the hall was concreted, there seems to be no damp membrane, so the bottom step is two inches shorter than the rest . I have been told that I need a new staircase and I can see that this would be for the best. My problem is that where ever I have looked I can find how to fit the new case to the floor and the wall but NOT to the upstairs hall floor, I am very good at following descriptions but not at winging it . Help