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dncllns 09-30-2010 12:25 AM

jack size for house levelling
 
We have a brick, single story home needs relevelling. Wondering what size bottle jacks would be best for the job. 20ton? 30 ton?

Bondo 09-30-2010 06:29 AM

Ayuh,.... I use 12 ton jacks...
They'll lift Plenty, 'n are smaller, lighter to work with...

1910NE 09-30-2010 08:50 PM

depends on the overall size of the house, and how much of it you are going to do at once. As an example, I recently jacked up my back house (approx. 180 SQf.), using three 12 ton jacks. It was probably overkill, but made the job easier.

downunder 10-01-2010 05:30 PM

I have always used screw jacks for leveling. Raise the jack about 1/4 turn every few days or once per week. You just can't get the gradual precision with any other kind of jack. Snatch it up with a bottle jack and something's going to give, probably not where you want. IMO IMO IMO

steveel 10-01-2010 05:43 PM

If you just have some dips in the middle of the floors that's one thing.... a scissors jack from a car can probably handle that ok. If you're releveling exterior walls for sill or foundation repair, that's something else. I agree with comment that screw jacks make it a lot more controllable. You can go up with a measure of control using a bottle jack, but its much harder to release the pressure GRADUALLY with that type of jack.

concretemasonry 10-01-2010 06:44 PM

You have a brick house and that opens up some additional speed and control problems. You cant afford to crack the brick, since it can be ugly and is expensive to repair.

Dick

downunder 10-02-2010 10:24 AM

Quote:

a scissors jack from a car can probably handle that ok.
:laughing::laughing::laughing:

steveel 10-02-2010 08:37 PM

why laugh? Compare the load rating of your own car jack with the weight of a sagging joist in a floor, that holds nothing but itself and the sofa. If its walls and roof that need jacking that's different.

concretemasonry 10-02-2010 09:53 PM

Are you lifting interior walls or the entire house.

If you are lifting/leveling a beam, you must do it slowly, over several days, depending on the amount to be lifted. This gives the structure a chance to distribute the loads differently due to the leveling. Any Bozo can push it up quick, but could end up with cracks everywhere.

Dick

downunder 10-03-2010 11:02 AM

Quote:

why laugh? Compare the load rating of your own car jack with the weight of a sagging joist in a floor, that holds nothing but itself and the sofa. If its walls and roof that need jacking that's different.
CM, you tell him. On second thought....

steveel 10-03-2010 02:22 PM

If you care to share, Down, I like to learn.

downunder 10-05-2010 08:17 PM

Well, to start with the original post was
Quote:

We have a brick, single story home needs relevelling. Wondering what size bottle jacks would be best for the job. 20ton? 30 ton?
This does not say only a sagging joist. The post says the house needs levelling. This is a job that requires a certain procedure. That is why construction work has so many codes. If it is not done right, more damage is caused and/or people get killed. Someone might could do this with a car jack. Frankly I don't see how you get the control you need, but maybe that's a shortcoming I have. Just like you could just use black "electrician's tape" to connect wires in a junction box instead of wire nuts. It probably would work, for a while at least. As far as that goes, why even use a junction box? Just tape 'em together and stuff 'em back in the wall. It may only be a joist, but that's not what the post says. The OP recognizes that he needs a substantial tool. Cars only weigh a couple thousand pounds, houses much more.

Getting under a house and jacking it up is not the same as raising a corner of the back porch. When you raise a joist, then you raise the floor decking. When you raise the floor decking, you push laterally to the walls or raise a wall if it is nearby. Take an 8ft board, bend it and squeeze it between two walls 7ft apart. Get enough bend and it will go. Now, push up on it and straighten it back 8ft. Watch the walls! Somethings going to move. When you start moving walls, you push up on the roof which is resting on the walls. If it's all nailed, screwed, glued, and bolted together, when you push on one you push on all.

The house will "absorb" some of this IF it is done slowly. That is why a screw jack is used. By turning a fraction of a turn periodically, the house can adjust to the pressure. It didn't get out of level overnight.

Why not a car jack? It is my policy to use whatever equipment that can handle the most I might have to put on it. You get started jacking up and something happens, you want to be able to handle it. Now if you were replacing a header over a door and just needed to take the weight off for a few minutes and only raise the ceiling maybe 1/16 inch or less, I could see it. I just use a couple of cripple studs between a top and bottom plate. Don't even need a jack for that. I guess it just depends on how much of what you need to raise, and what the worst possible outcome you are prepared to accept is.

Bottom line is, there's a lot I don't know. But I know this- I've never gotten hurt using my tools (my good tools, not the ones I loan out) doing it my way. And I will tell my boss, "That's an unacceptable risk for me." in a heartbeat. I don't get paid to get hurt.

steveel 10-05-2010 09:25 PM

Thanks for the time you took writing that, Down. We see this the same way, I just wasn't ready to assume what scope of a project was meant by the single word "releveling". A lot of folk post here about releveling their floors after all. It would help if OP's include more details or a pic or two.

Maintenance 6 10-22-2010 02:55 PM

I'm with Downunder. Any time we level houses or straighten shifted buildings we use screw jacks and screw driven rams or pullers. They're much more precise and can't bleed down. If you're gonna level a house, you need to go slow. It didn't sag in an hour, don't expect to put it back in an hour............ unless you like splinters and cracks.

Angelbuilder 07-22-2012 07:43 PM

Jack size for house leveling
 
I can appreciate the screw jack preferrence. I use a 20 ton jack when putting in new support but I need to level a three story victorian. I had someone else jack it up and replace the termite eaten sill but he did not do it right. He apparently used a beam at least three to four inches smaller than the original which was easier to get in place. Now the living room slopes to the middle of the house but the dining room is level and they are one open living area. I was considering getting four steel I- beams and after measuring and adjusting each rafter( because I notice some of these older rafters are wider than the other by at least an half inch or more) jack one at each wall and one at the center of each side of the basement. what size jack do you think I will need considering the weight of the beams and the house?


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