Any Engineers or Architects?? | FerrariChat

Any Engineers or Architects??

Discussion in 'Other Off Topic Forum' started by darkalley, May 31, 2005.

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  1. darkalley

    darkalley Formula Junior

    Aug 17, 2004
    826
    Full Name:
    Jim
    Here is my problem. I have a very, very small lake front summer cottage in upstate NY that is leaning to one side. The building was built around 1950 and sits on concrete blocks that have cracked and sunk into the dirt. One corner of the house is sitting 12 inches to low(I ran a line level from front to back of the structure and I'm using the front of the building as the reference). I want to jack up the house and replace the footings on my own. I'm also renovating the inside. I'm trying to determine if three 20 ton hydraulic floor jacks can lift one side of the building. Can anyone do the math and tell me if it will work. Here are the specifics.

    all old lumber and totally empty

    Building is 25 feet by 25 feet.
    one main floor, with 3 rooms and an empty loft on the second floor
    Floor joists are true 2x8s, the floor joists sit on a 2x8 box with a beam running down the center
    walls are true 2x4's, no sheet rock just 1/4 inch paneling(I'm replacing)
    10 Single pane old windows.
    building has wood clapboard siding
    The building does have an 8 ft by 25 foot front porch but that is on the front of the house but I 'm only working on the back end. I only need to lift the back end. Any thoughts?? Do you need any more info? I have three really old big screw jacks that I'm going to use as backups to the hydraulics to support the building in the event the jack fails.
     
  2. LMPDesigner

    LMPDesigner F1 Rookie
    Silver Subscribed

    Nov 5, 2003
    3,208
    Atlanta Georgia
    The problem is not going to be the capacity of the jacks. 60 tons is way more than that structure will weigh.

    The issue is two fold:

    1.) What and where are you lifting?

    2.) Can the house structure stand the stress ?

    If you can expalin how you plan on doing this (maybe some pictures of house and where you are lifting) then maybe I can help you some.
     
  3. robert biscan

    robert biscan F1 Veteran
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    Jan 17, 2003
    5,082
    Nashville and Palm b
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    robert s biscan
    Don't put the jack in one spot and expect to lift it. Get a 4x4 about 4' long and put it over the top of the jack and pick up a longer section. Spread it out. It sounds like a very light structure and maybe weighs 100#/sf total. You could block up the exterior after you brace the floor temporarily. The 4' board is perpendicular to the joists. You will need to lift and brace it in different places .
     
  4. Meister

    Meister F1 Veteran
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    Apr 27, 2001
    5,516
    Duluth, MN
    Full Name:
    The Meister
    I manage a number of log homes and boat houses that were built around the turn of the century and I do a lot of jacking. I use the old time screw jacks a lot, so I'd be inclined to use those. Grease them up, get a long, strong steel bar to turn them and your good. If you can rent some house jacks/railroad jacks that would be the way to go as they tend to have a ratcheting sort of action that really saves on time and your back.

    If you have three jacks... dig out three seperate areas under the sill of the suspect area. One close to the corner and the two others 4-6 feet away depending on rocks/roots or other impesiments. Dig the holes deep and wide enough for a good size wood pad (24"x24"x6") under the jack, the jack itself and some sort of plate on top of the jacks, (4x4 or 2 or 3 2x6's nailed together, about 6 feet long).

    Try to pick up as many joists as you can at one time. Picking on one joist or even the thin sill could just compress the area you are jacking. The idea is to spread the weight as you go up.

    Go slowly until you reach the height you need... go a little higher and then pour your footing, slide in your new blocks or pressure treated timbers or whatever you plan to have the structure sit on.

    A good way to deal with the areas (space) where the jacks were after you let the structure down and remove the jacks is to install air vents...like the ones you see in an concrete block foundation wall.

    Good luck.
     
  5. darkalley

    darkalley Formula Junior

    Aug 17, 2004
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    Jim
    #5 darkalley, Jun 1, 2005
    Last edited by a moderator: Sep 7, 2017
    OH. here is a picture of the house. I am jacking the end opposite the porch. Regarding the placement of the jacks..... Let me know what you guys think based on this crude drawing.
    Image Unavailable, Please Login
     
  6. darkalley

    darkalley Formula Junior

    Aug 17, 2004
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    Jim
    #6 darkalley, Jun 1, 2005
    Last edited by a moderator: Sep 7, 2017
    i have to figure out how to resize my drawing. give me a few minutes..... here you go. do you think if I put a 6x6 block about 12 inches long on top of each jack that would work?? the box to the right represents the floor joists which sit on top of the box to the left. the key here is that the bottom box has doubled up 2x8s on each end, this is old lumber so they are really 2x8's.
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  7. Horsefly

    Horsefly F1 Veteran

    May 14, 2002
    6,929
    Agreed on the 4x4 to help distribute the lifting force across the floor joists. Even better would be an old railroad tie which you can buy at some home supply stores. They're used as landscaping timbers but are really about 10x10.

    Why does only New York have an "upstate"? I've never heard of "upstate" Arizone or "upstate" Idaho. What's "up" with that?

    Sincerely, Horsefly in "mid state" Arkansas.
     
  8. darkalley

    darkalley Formula Junior

    Aug 17, 2004
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    Jim
    Those City guys need to seperate themselves......... how about his idea. Since the wall I am jacking up sits on two 2x8's how about if I drill through them and bolt another two 2x8's 6 feet long at each of the jack points?? Remember, because of the box under the floor joists a railroad tie would sit inside the walls of the house. The two 2x8s are basically my sill plate. I know what I mean but I have no idea if this makes sense to anybody else.
     
  9. darkalley

    darkalley Formula Junior

    Aug 17, 2004
    826
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    Jim
    #9 darkalley, Jun 1, 2005
    Last edited by a moderator: Sep 7, 2017
    ok, I wasn't going to post this but why not. I'm not really going to use traditioal footings, I can't because the ground is too soft. The house was built on a sand bar that has about 28 inches of top soil over the old sand. The top soil is pretty stable but if I dig down I hit water at 24-28 inches and sand as well. The right solution would be to have pillings driven down but I'm trying to get a 5 year fix that I know I will have to shim yearly. Here is my idea. I have to float the building on top of the top soil as much as possible so what do you think about three 10x10s next to each other with six 36 inch 10x10's sitting on top of them with bolts holding the bottom ones together. below is a picture of what i mean......... I realize this solution will probably give most architects a heart attack.
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  10. robert biscan

    robert biscan F1 Veteran
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    Jan 17, 2003
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    Nashville and Palm b
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    robert s biscan
    The more contact area touching the top soil as you call it the better. Your building is exrtemely light. Why not add more piers that are 3' sq. or so and put them at 6' on center with new girders to hold up the existing floor. If you could dig holes down in the soft stuff in the bottom and fill with concrete it would make them stronger. Water doesn't really hurt after all these years. Usually after 10 years the original suff is consolidated. The top soil will settle.
     
  11. darkalley

    darkalley Formula Junior

    Aug 17, 2004
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    Jim
    problem with diggin down is the pillings will sink really, really fast...... I agree about the more area touching the ground the better. I plan on using a few more footings.
     
  12. ItalianSpeed

    ItalianSpeed Rookie

    Feb 7, 2005
    38
    CA
    Full Name:
    Sam
    Reviving this thread because I am curious about the outcome. Is the project finished? If so what did you do to re-level the place?
     

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