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  1. #1
    Tripper Guest

    Default Bracing Foundation Walls

    Hi,
    wondering if anyone has a good method of back-bracing foundation stemwalls before backfill?
    I know some parts of the country put the box on first but, for those who don't, any suggestions would be appreciated. I'd like a good method for a basement with a center footing and also for one with no center footing.
    Thanks a lot.
    Jeff Tripper

  2. #2
    Peter CGR Guest

    Default Re: Bracing Foundation Walls

    I would never backfill a basement foundation without first installing the entire floor system. It may make it harder to do the work without backfill but the cost are far less than a bent foundation because of no support and I would think far less than some temporary bracing to keep the foundation straight while backfilling.

    The diaphragm created by a properly framed floor will be more than adequate to keep the top straight, the bottom of the wall is secured to the footing and I doubt that any backfill will bend the wall in the middle, even if you backfill the day after you pour and set up the floor. Why mess with any other way to do it. Good luck.

  3. #3
    Tripper Guest

    Default Re: Bracing Foundation Walls

    Peter,
    How do you square up your foundation? It takes us minimum 2 hours to get it square and that's with our feet on solid ground. I know that for me getting a good square-up with drops, jogs, ledges and other obstacles would cost me way more in labor time without backfill than temporarily bracing the walls with material that later gets used in the framing. And it is also a regional thing because here in Michigan you almost never see the floor on before backfill. It's probably different where you are. I was just looking to improve my bracing, not change my methods.
    And yes, walls can bow in the middle. In fact, two weeks ago I visited a jobsite where the the builder was sheeting the roof when one entire basement wall completely caved in. The footing and rim joist were just fine but the wall was laying on the basement floor. Granted the situation could have been avoided but nevertheless, it happens.
    That's why we brace the wall near the high center since we only backfill to about two feet from the top.
    Anyway, for every way one guy does something, there are 2 more that do it another.
    I appreciate the response(you were the only one) and the dialog.
    Take care,
    Jeff

  4. #4
    mike pelletier Guest

    Default Re: Bracing Foundation Walls

    We always deck our block foundations before we backfill and we brace them too. placing vertical planks full hieght of the foundation at 6-8 foot intervals. A second diagonal plank runs from the ground to midway up the vertical plank. Braces are located opposing one another with a third plank lying on the ground cut to fit the space between the opposing angled braces. Everything is snugged and tacked with a few duplex nails. We leave them in place until the roof is up.

    I know it doesn't sound like much, but with careful backfilling I haven't had a failure in over 20 years, and the guy who showed me never had one for 30 years before that. The test of time is good enough for me.

    I think it is important to be careful backfilling, you have to watch the trench constantly, and the fill material needs to be free of large stones or debris that can cause damage. You need to proceed with gradual lifts. We actually get in the trench with shovels keeping a coushion of gravel between the foundation and any hidden incoming rocks. When I say in the trench, I don't mean in harms way, but where you can see whats going in, and protect the drain fabric and such.

    Lastly, you need dry fill and a careful machine operator who understands the word "stop".

  5. #5
    Tripper Guest

    Default Re: Bracing Foundation Walls

    Hey Mike,
    that sounds good(the test of time).
    I'd like to try it on the next house. Can you be more specific on the details? What size planks, what's the orientation of the planks? Any kickers? What if you have a footing down the center?
    Thanks a lot,
    Jeff

  6. #6
    mike pelletier Guest

    Default Re: Bracing Foundation Walls

    Jeff,

    we always use the form lumber from the footings, usually 2x10s or spruce scaffold planks. If there is no center footing we fill between opposing brace/planks with flat planks lying on the ground or drive 2x4 stakes in the ground. We don't usually add kickers, gravity, friction and a few nails hold everything in place.

    As to the geometry, our braces are usually 12 feet long or so, angled from the ground to midway up the foundation wall. Snugging the plank is accomoplished gently pushing down( just a little bit) in the center. This will usually cause the top edge to bite into the vertical plank on the wall. Then nail with duplex nails.

    I should stress be careful that workers don't climb on the inclined planks. I've never done it, but there is tremendous leverage capability here and I suppose you could push a wall out! Once you are backfilled I wouldn't worry about it.

    Everybody does things differently, but we usually bring in item four and grade the floor area after we have a few courses of block up. It is still easy to get the machine in and it provides a nicer work area for the masons. I don't get all the block delivered at once. Just enough cubes to get us up four or five courses. I always leave a clear shot for pulling diagonals and checking square on the way up.

  7. #7
    Guest

    Default Re: Bracing Foundation Walls

    Thanks a lot Mike for the info.
    One more thing if you don't mind.
    It seems like without a kicker or some kind of cross brace at the center of your diagonal brace it would be pretty easy to bend that thing. If I'm understanding you correctly, the long side(9 1/4") of the 2x10 angle brace matches up with the long side of the verticle on the wall?
    Or do you put the angle braces rafter style with strapping across the back of all of them?
    Either way it seems like I could bend a 2x10 by pushing on an end with a little force unless it had significant cross bracing.
    Your test of time testimony is more what I'm interested in. I must be missing the physics of the system. We've done almost those exact braces before but we also run 2x4 from the center of the angle brace back down to the bottom of verticle.
    Sounds like we're on the same page if I understood you correctly.
    Ive also wondered about running that verticle 2x10 horizontally instead and running the diagonals rafter style with strapping across the back. Which do you think would disperse the wall weight better?
    Thanks for the responses.
    Take care,
    jeff

  8. #8
    Tripper Guest

    Default Re: Bracing Foundation Walls

    Thanks a lot Mike for the info.
    One more thing if you don't mind.
    It seems like without a kicker or some kind of cross brace at the center of your diagonal brace it would be pretty easy to bend that thing. If I'm understanding you correctly, the long side(9 1/4") of the 2x10 angle brace matches up with the long side of the verticle on the wall?
    Or do you put the angle braces rafter style with strapping across the back of all of them?
    Either way it seems like I could bend a 2x10 by pushing on an end with a little force unless it had significant cross bracing.
    Your test of time testimony is more what I'm interested in. I must be missing the physics of the system. We've done almost those exact braces before but we also run 2x4 from the center of the angle brace back down to the bottom of verticle.
    Sounds like we're on the same page if I understood you correctly.
    Ive also wondered about running that verticle 2x10 horizontally instead and running the diagonals rafter style with strapping across the back. Which do you think would disperse the wall weight better?
    Thanks for the responses.
    Take care,
    jeff

  9. #9
    mike pelletier Guest

    Default Re: Bracing Foundation Walls

    Your right you can bend it easily, that is the function that makes it easy to snug-up. Like I said you have to be careful not to climb on them and stuff.

    We use 2x4 flat to line walls all the time, in that instance we use a kicker to spring the 2x4 effectively pulling the wall in where needed, the kicker is then tacked in place.

    I am a real ***** about braces, I leave them up until the roof is framed and shingled and I watch them like a hawk. Give it a try, I think it will make more sense as you actually do it.

  10. #10
    Ted Guest

    Default Re: Bracing Foundation Walls

    Hi guys,

    A couple years ago at the World of Concrete show I saw this "Footlock" system. You cast a heavy ring bolt, or like a loop of rebar, into the footing, and put a shoe up against the wall and one on the floor of the foundation hole. Then you put a 4x4 from one shoe to the other, run a chain from the shoe on the wall, down to the footing, and out to the shoe on the floor, then lock the chain down with a load binder-type lever. It's pretty heavy duty. Looked to me like a real sound brace -- reliable because it doesn't count on a stake into the earth or anything -- but I can't speak to the costs vs. benefits -- they claim it saves money, but don't say how. Of course one foundation collapse less would more than pay for it, ha ha... You re-use the shoes and the chain -- that's the product -- but you leave the ring in the footing and cast it into the slab. Here's the link to their site:




    Footlock foundation bracing gizmo

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