If you feel you really, really must level out the house by jacking, hire a professional. This is no DIY project. There are very real dangers to the house and anyone doing the jacking.

This is probably much different from raising an entire quadrant of a house such a large amount, but my Dad was a DIYer and my house had a cracked joist and sagged a bit in that spot when I bought it. He put a jack under the spot and emphasized that it must be jacked up slowly.... I remember that he firmed it up and told me it shouldn't go more than a quarter of a turn to tighten it each year, as needed.

Hire a professional ... you can end up with a 125 year old pile of rubble on top of you.

And cracked chimneys, leaking pipes and a bunch of "minor" things.

Talk to a structural engineer. She/he can give you real info about this.

Diane

I've done it a few times and never had a structure implode,fireplace crumb,water line bust nor credit score change. Just use common sense while planning the job and while in the process. Just refrain from doing something dumb like removing a bunch of block/pier supports while structure sit's up on jacks. First check level of intire structure while makeing a sketch showing low spots as well as how low they are. Cut up and place approperate number & thickness of shims ( use at least 3 shims) next to respective piers before raising structure. Raise windows and leave doors open while moving structure. 4 or 5 jacks and a helper or two will make it go smoother,especially if it's a tight squeeze underneath. After lowest point is raised an 1'' or so with 2 or 3 jacks,check surounding piers to see if joists are raiseing off on them. If joists come off piers that have shims laying by them,insert all that will go in. Returning to piers where jacks are,insert as many shims as possible then lower weight onto piers. Move jacks and repeat. Alternatly,if you have enough jacks,just raise everthing at one time. Point is not raiseing one area all at once while surounding areas remain static will minimize drywall cracks and pulled frame joints. Not all inclusive instructions,only a few things to consider along with other info you geather.

" He put a jack under the spot and emphasized that it must be jacked up slowly.... I remember that he firmed it up and told me it shouldn't go more than a quarter of a turn to tighten it each year, as needed."

It may have failed slowly, but doesn't need to be fixed that way. Evenhandedness is the key here. A little bit at a time, but put it where you want it right away, support it properly, and be done.

Thanks for the warnings of be careful and hire someone, I've goggled and watched several u tubes and being a diy I'm not afraid of the house falling on my head , from what I,ve read heard is to go slowly. wish me luck I'll report my progress

I've jacked buildings a few times to replace rotted sills and repair foundations, not explicitly to level, but klem1's process is sound. Careful, go slow, and overdo redundancy in supporting the structure and you should be fine.

Fortunately I didn't find out this was a "pro only" job until after I'd done it a few times.

I think you use metal plates to distribute the pressure of the jack along the beam. One danger is one of those plates falling and hitting you in the head.

Good point,small detail that could potentialy prevent big problem.

You really need to consider if you want to jack and level it or just stop it from sinking. You will likely need to repair cracking in every interior wall once you jack it up, unless you have wood finished walls like wainscoting. Also, have you determined why it was sinking on the first place?