Rotted Floor Joists, 1900 Farm House
We're buying a 1900 farm house (great price but needs LOTS of work, most of which we are confident we can do, but we've never faced this issue before...). One part of the house is currently not useable because the floor joists have never been updated (still post-type, rotting). This part has no chimney, no roof sagging, etc. – just weak main floor as far as we know. However, the stone foundation is being shored up in places in this section. We're planning to bring out an engineer or two to look over the situation once we have closed on the house.
We're considering a plan of using temporary jacks and beams to support the floor beside each existing joist, and begin very slowly jacking it back to level. Once level, replacing small sections (5-6 feet) of the foundation at each end of where the new floor joists will go with block foundation, working around until completely replacing the old foundation (new joists resting on new block). ls this a reasonable approach? How will I know when it is time to raise another click on one or more jacks?
We've considered having the house raised, foundation excavated, and having a foundation poured - however, the joists in the weak section need to be jacked and repaired first. This plan seems like overkill.
We need to have a good plan before approaching the Building Inspector, and have never used jacks. We have talked with an old home repair consultant (licensed) coming in to assist, but he does not give advise on basements.