As I am new here I thought I would toss this out and see if anyone has a better idea. My home was built in 1966 and we have been in it for over 10 years. Ths issue is that the structural 6"x6" basement floor post to the second floor were not attached to a floor joice, they put it on the actual floor. Now I have the floor coming up under my daughters door as the house settles more. I have found another one just like this by the furnace downstairs but does not seem to effect anything, yet.
My idea, because the support post is in-between the floor joices I was going to use a floor jack to lift slightly and take out the post. Then fasten a strong I-Beam between the joices and cut the post down and place on the I-Beam in the exact same spot.
My question is can I leave the floor jack in place and undo it a little at a time to allow the floor to sink back down. All the doors inside the house near this area are out of whack and don't close well.
any support for the posts must be solid to the foundation. If in the middle of the house this area must have at least a 12" deep 24" X 24" footing. The area between the floor joists must be blocked with material the same size and strength that was required for the post. Raising it with a jack and slowly lowering it will work fine. Move slowly, only 1/4" per day to avoid cracks.