jacking a beam under a house

Discussion in 'Shop Talk' started by tat, Jan 13, 2005.

  1. tat

    tat Active Member

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    I just purchased a house that is sagging =<4" on 25' of the back outside wall. the beam had a water leak on it years ago. Someone placed a new 4x6 beam under it but they laid it on its side and they did not lift it up they only set it under the floor joists where they were the did not raise it where it was originally. I had a pro look at it several months back and he suggested setting the 4x6 on edge and jacking it into position and blocking it up. The house is pier and beam and is a single story with wood siding. I found a source for hydrolic jacks and I have considered doing it myself. Do any of you have suggestions for me doing this myself. Also what size jacks do I need, I have heard that 10 or 12 ton jacks are enough for single story houses.

    TAT
     
  2. John Hill

    John Hill Grand Master

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    I expect a 10 ton jack is more than adequate.

    You will need to jack it a little at a time in several places.

    If I was doing it I would get some 3x2 or bigger and cut a good supply of wedges. I dont know what the beam is supposed to rest on but around here it could be a concrete pier or a wooden 'pile' (a short post in other words). Are the original piers still there in good condition? If not you need to get a few of those. You need to set these in place with a good footing in a straight line of course where you want the beam to be, you need to leave enough room to get the beam into place then use the jack to just take up the weight and put in two wedges, one wedge reversed on top of the other so you can get fine adjustment. The jack goes under the new beam. Do the same at several other points and when you return to this one there should be less or even no pressure on your wedges. Continue on in this fashion using you wedges and additional blocks until you reach level.

    I should mention that the wedges go between the new beam and the top of each pier.

    You should put some damp proofing substance on the top of the pier, tar paper or something like that.
     

  3. Blu3duk

    Blu3duk Well-Known Member

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    generally house jacks are screw type jacks, for the simple reason that you dont want any problems from oil letting the jack down at the wrong time, and maybe too the screw jacks have been around for a few days longer than hydraulics have.

    Whne jacking it up dont forget to shut off the water and disconnect it from the incoming ground pipe, and then check the plumbing/sewer pipes after letting it back down too. watch the electrical wires if that is buried.....

    William
     
  4. norris

    norris Well-Known Member

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    I thought the screw type jacks were a thing of the past. I've used hydraulic jacks to repair sagging foundations and they work fine. Ten tons is enough. One thing you might consider beforehand is to dig out and pour a small footing or two on which to place extra blocks so the concrete can cure a few days first and not crack when you put the weight on it as has happened to me on a large two-story.
     
  5. fordy

    fordy Well-Known Member

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    ................If , the total length is only 25 feet , I would look into the possibility of renting\obtaining an I beam that would span the full length of that side of the house and ...Inset the Ibeam....a couple of feet or so , so that I could have enough room to install whatever leveling\supporting structure(s) that I felt was necessary . And , more than likely , the rest of the foundation is going to Need some leveling as well . You will probably need to address the "whole" support structure to really achieve a truly Level home that won't sink with the passage of time , fordy.. :)
     
  6. agmantoo

    agmantoo agmantoo Supporter

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    Get yourself a water level, a couple of good mechanical jacks, and a piece of steel beam. A single 10 ton jack is not adequate for the house leveling task that I have done. It took 2 each 20 ton jacks to lift the last house I leveled. Lift only a little every third day or so. In so doing the house will slowly adjust to the lift and not open up damage elsewhere. When you get level, fabricate piers and using wedges secure the house in place.
    PS.... with the water level find the highest place in the floor beams, level the entire house to that reference point.
     
  7. Darren

    Darren Still an :censored:

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    I vote for using 20T jacks too. Sam's Club usually has them in the fall or winter for around $20 which is a lot better than the $60 I've seen. Use some sort of cribbing with the wedges to support the beam while repositioning the jacks while doing the lift. You may need a small steel plate or a heavy piece of C channel on top of the jack to prevent crushing the wood beam where it bears on the jack.
     
  8. tat

    tat Active Member

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    If I use a 25' beam how many of the 20 ton jacks as opposed to the 10 ton jacks would I need? Is the new 4"x6" treated beam that is under there already strong enough if I turn it on its edge 6"


    TAT
     
  9. Darren

    Darren Still an :censored:

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    I would try one 20T to start. House movers jack from within the cribbing which is a bit more difficult for the the do-it-yourselfer. If you divide the beam into roughly three equal parts, that means you would build two new piers to support the beam about 8' in from the beam ends. I'd jack at the midpoint of the beam which would be between the new piers.

    As posted previously don't get in a hurry. Figure on taking maybe weeks to allow the house to adjust without cracking. Build the piers as you go up. The idea of using a water tube level is an excellent way to level the joist. Otherwise you could use a regular level above on the floor.

    If the crawl space is damp, wipe the exposed jack cylinder with a light oil to prevent the exposed chrome from rusting.
     
  10. Ken Scharabok

    Ken Scharabok In Remembrance

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    Guess I'm missing something. Sag is 4". You want to convert a 4" x 6" to a 6" x 4" in height. Aren't you still 2" short of level?

    Screw-type house jacks appear on eBay on a fairly regular basis. They can be sold there also after use.
     
  11. tat

    tat Active Member

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    Some time ago someone just put a treated 4"x6" treated beam under there. The did not jack it any, it was set under there laying "flat" on the 6" side. I am going to invert it where it is laying on the 4" side 6" up and then I am going to jack it up from there to the correct height.

    TAT
     
  12. mtman

    mtman Well-Known Member

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    if you have a center beam that the joist attach to on both sides watch you dont pull the joist out from the center beam i jacked up a few inches i put quick tubes filled them with cement 8 inches from the beam then i took 2inch steel pipe welded a pice of flat steel on the bottom and one on the top the one on the top had a hole in it i put a pice of 1 inch threaded rod in it with a double nut on the bottomon the top of the rod i welded a pice of flat steel i turned the nut until it was tight against the beam then i locked the second nut down minture lolly column
     
  13. rambler

    rambler Well-Known Member Supporter

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    Here in Minnesota every hose has a full basement it seems. So I'll tell you how to fix it easily 'here', but I don't understand what we are dealing with either....

    Are you in a crawl space, or a basement?

    The 4x6 is laying flat on it's side. But, what is it laying 'on'? A foundation, posts, dirt - what? What is the floor of your crawl space/ basement/ wherever this is - dirt, concrete floor, ? Why did it sag to begin with - not enough supports, or the supports puch into the floor, or ?

    Here, I would buy 2 screw jack poles, put them in place, screw them up every couple days a little tiny bit, and stop when it was level. Job done. The 'jacks' become the permanent poles. They don't cost any more than the hyd jacks you are looking at. Different sizes from 3' to 8'.

    I'd never use hydraulics, they settle & leak, and will go down about as fast as you want to go up. Hard to do slow steady work that way, a screw is much better for this type of thing. Easy for me to say tho, there are 3 or so old screw jacks laying around the place...

    --->Paul
     
  14. mtman

    mtman Well-Known Member

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    what i was saying was for a crawl space not a basement
     
  15. Cosmic

    Cosmic Well-Known Member

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    The more jacks and support points you have the better. I have jacked up smaller houses just using a series of car jacks. Some hydraulic and some the screw scissor type. Instead of jacking one point and then attempt to block and brace and move the jacks is sometimes better to use many smaller jacks that stay in place. Each jack is bearing only a small portion of the total load.

    Whatever the support beam you have to plan on jacking and support at a point that allows removing the old bearing beam and replace with something adequate and rebuild of the pier or whatever support system. A series of jacks that remain in place along with soldier supporting bracing that is raised as the house is raised can allow you to get at the entire beam / support system once the house is high enough in a totally free manner. Usually you set back on the joists a few feet to give the work clearance. You are not jacking on the beam itself.

    As stated you want to be totally aware of the plumbing, electrical and anything passing thru the foundation, sill house interface that can be damaged. Plus want to jack a bit, run around and see the effect on various doors, windows, etc. Some can be jammed, some may have been altered to fit as the house settled. Some windows can fail to open any more. Trick is to only jack a bit and make a tour to see the results. You can do major plaster, flooring, etc damage if you get too frisky.

    Many car scissor jacks work well with the main lifting started by at least 2 ton hydraulic jacks at a few points. To really do a good fix, you also should understand why it sank in the first place. Maybe the pier foundations / footings are a bit lame and should be corrected at this opportunity.

    You need some method of establishing a reference or level line. A string and line level, a laser level or water level. Just using ordinary 4 foot levels on the floor above with a paper record works to give a good picture of results too. You must understand the lifting project in terms of the whole house structure and what is being effected, not just one small area or wall of the house.
     
  16. 65284

    65284 Well-Known Member Supporter

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    Don't know if this applies in your case or not, but, be very careful/aware of any chimneys/flues/fireplaces that are so common in these older homes. I can tell you from experience it doesn't take much to collapse one of them. And I guarantee it will get your attention when one falls and you are under the floor jacking. You will most assuredly make a faster exit from that crawl space than you have ever made from anywhere.
     
  17. weekend warrior

    weekend warrior New Member

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    I have a 30 x 20 cottage that I wanted to cathedral the ceiling. I tore down some bedroom and bathroom walls and decided to cut out a 8 x 20 section down the middle. I realized after doing this that the front of the house had no support. It buckled ever so slightly, probably less then an inch and basically right in the middle of the 8' section. When I put the bedroom wall back in and attach it back to the one side wall that I did leave up and the new bathroom wall on the other side I need to put up, can I assume that I can just lift the middle of the section I cut out and tie new ceiling joists back in? I also heard about using a cumalong and pulling the section in and then nailing down the ceiling joists. Any thoughts?
     
  18. Cosmic

    Cosmic Well-Known Member

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    Tough to say. You may not have just caused a bow down but warped the square of the general house structure, viewed as a top view. Which brings up the tricky question of how to check???

    When a stick built house is being framed the exterior walls are put up first and then checked for square using a diagonal measurement without any interference from internal walls. Then temporary braces are installed to hold it so. Internal walls are added, more bracing, then levels above and finally the roof and all its support structure. Once the entire building is tied together with siding, roofing sheeting materials the temporary bracing is removed. In theory everything should be plum, true and square and remain so.

    It is typical to use a come-a-long to provide pulling force in those situations to do adjustments but the prime need on your part is how to judge your point of being square or reference in a particular plane. You probably are blocked by internal walls, structure.

    Duh, you have a 3D problem. Maybe something like a laser level and try to sight various planes and decide what really did change. Do you really understand what was load bearing and what was not? Horrible problem to have, solution probably iffy. A bit like some of those houses that are warped by hurricanes. Bits and pieces solutions never seem to fully do the trick. :rolleyes:

    Guess first one tries to jack everything level, then maybe play with a problem in two planes. Best not to get into this pickle in the first place.