I live in a raised ranch that is about 25 years young. The stair squeak something aweful. I have full access to the underside of them but it seems that everything I read to be done is. They are blocked, shimmed, nailed etc. So with the help of a friend as he walked up and down .I noticed that the entire stair would bow. Some worse than others. ow can I sure up the stairs to stop the bowing, in turs stopping the squeaking?