We have a 3 storey 100 yr+ house. The floor joists on the first floor are 2"X 8' 2' on center with a 1" diagonal subfloor on top of them. They span approx. 18' with no center beam. There has been some deflection of the joists. All of the stairwell openings have been framed with single headers etc. The joists rest directly on the the foundation walls and are cemented in place. There are no cross bracing between joists or doubling of joists under parrell walls. Some of the joists appear to be split. 1. If we attached a new 2"x8' to the exsisting joist should we have the new one resting on the foundation wall? 2. Should we be reinforcing the stairwell openings? 3. We are planning to put a 2"x12" center beam down the middle of the basement, with a plan to try and level the foor somewhat, is this a good idea?
Answer:
I would not bother with the sister joists as they'll not do a whole lot for you on that kind of a span. I would though, install the beam and jack it into place before placing the tele-posts under it. Be very sure to do the lifting with the appropriate jacks and not the try doing with the tele-posts.
