Anyone ever have to jack up a floor before?

[amdskip]

I helped jack a 1 and 1/2 story house up not that long ago. House had a basement so we did it slowly and moved 2 foot at a time and then went back and jacked each post location more. Got it done in a night. Used wood posts and a couple metal posts to hold it all up.

How thick is that concrete under the house? If it's just going to sink more I would pour a new footing where the posts holding things up go. It may be hard though with that limited amount of workspace under there.

 

[Rastus]

I did exactly the same thing to a house once. It was an old house that a floor joist was cut to install a furnace many years before. The floor sagged. I went into the crawlspace with a concrete pier block, a 100 year old railroad screw jack, and some pressure treated lumber. I jacked that floor up about 8" in a couple hours. No drywall cracked. BTW, I dug a hole with a GI entrenching tool 3' deep to meet code to set the pier block in, so frost wouldn't heave it. As long as you do not have any wood meeting soil, you should be ok.

 

[iamwiz82]

Originally posted by: skyking
The entire crawl is concrete? Does it look like the concrete cracked out to allow this settlement?
A hydraulic jack will work fine. I have used them to move and lift houses before. If the beam is in two pieces with the joint over the post in question, you'll need two jacks.

If there is a pier block under it on dirt that appears to have settled, then consider bringing in some solid block concrete, like 4"x16"x16" and put in a couple of piers adjacent. jack the whole mess up, re shim the existing, and split the load onto those other piers also. Put the two jacks between the three piers.
A 10 ton jack is plenty, and you could easily buy rather than rent.
here is a 20 ton for 30 bucks.
You will not move the house 1.125" without cracking plaster, it does not matter how slow you go. Get it over with and fix it.

I cannot tell if the concrete is cracked because they put down plastic liner over everything, but it is definitely concrete, since I did lift the end closest to the entrance. The pier has settled, as it is lower than the other 6 piers on that joist, which is solid, btw. I have to wonder what is the issue here since this is the only spot in the entire hose with the issue, and of course it's affecting the room I wanted to lay a new floor in.