Post on Old Concrete Floor

Discussion in 'Homestead Construction' started by Studhauler, Apr 16, 2018 at 1:33 AM.

  1. Studhauler

    Studhauler Well-Known Member

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    Among other things I am a professional handyman, one of this weeks projects is to brace a sagging floor joist in a 100+ year old house. It is just one joist in need of support, so I am going to put an adjustable steel post under it. However the little 3" by 3" steel pad that come with the post seams a bit small,l to set on an old concrete floor, of unknown depth and quality. My question to you is, should I put a wood or steel pad under the factory pad? Both have their pros & cons.


    Thanks,
     
  2. CIW

    CIW Well-Known Member

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    Have you thought about jacking the joist up and sistering another one along side it? It doesn't leave anything sticking down that way. You eliminate the chance of breaking up an old concrete pad that may not have been meant to have concentrated pressure applied to it. Sometimes/many times they didn't even use any rebar in those old slabs. As you walk on the floor above you may drive the pipe right through the concrete pad below.
    Besides, sistering the joist is probably less expensive if there isn't anything in the way of slipping it up along side.
    Just some thoughts. Good luck.
     
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  3. Fishindude

    Fishindude Well-Known Member Supporter

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    I'd place an 8" x 8" x 16" solid concrete block under it or two pieces of treated 2x12 approx. 12" long, stacked and laid flat to spread the load out a little.
     
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  4. Bearfootfarm

    Bearfootfarm Hello, hello....is there anybody in there.....? Supporter

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    Use concrete blocks instead of steel or wood.
    Concrete is forever when in contact with dirt.
    Steel and wood can last a long time but will eventually have to be replaced
    A couple of 16 X 16 X 2 pavers would spread the load over a wider area.
     
  5. melli

    melli Otiose Endomorph

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    Curious, how much is the joist sagging (deflection) and length of joist.
    Any of the above ideas could work, I'd think.
    Aesthetically, I would lean towards sistering, if one joist, and if it doesn't have mechanical/electrical in the way.
    I would wonder what kind of shape the floor is in, given it's age.
     
  6. Studhauler

    Studhauler Well-Known Member

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    the answer came to me when I entered the basement to do the work. A concrete block was sitting there like I was meant to use it...so it did. Then a piece of lumber to cover the block. The joist was already sistered. Not ever going to be a finished basement. The rest of the floor will need work also someday, this joist was ready to fail.

    Thanks for the help,
    Cody
     
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