OK I will adjust my numbers. My old house has the stairs for the upstairs room over top of the basememnt stairs and they are too narrow and steep. I am replaceing and reversing both stairways. The current ones are 10" rise and 6" treads. LOL Has a landing and they are only 32" wide. We have to take furniture up on the roof of the rear of the house and into a window to get them upstairs. One last question. The new stairs are going to be 42" wide, 1" red oak. Do I need a center stringer for them or will just the 2 outside stringers be enough?