I have a tri-level house that was built in the mid 40's. The problem is the main floor is extremly uneven and wavy. I've looked at the floor joist (2 x 8's), via the basement, and have found them to be notched and toe-nailed into the main beams that run the length of the house. Only the joist's are splitting at the 90 degree spot of the notch causing the floor to sag on either side of the beam. Has anyone dealt with this problem? I guess I'm looking for the fix that will keep me from having to deal with a lengthly and costly major overhaul. Any comments will be welcomed. My old house is in need of many repairs but I feel that I shouldnt tackle any of them until this floor problem is taken care of.