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  1. #1
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    Oct 2008
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    Question Concrete Driveway Rebar placement?

    I am concerned that my elderly friend has made an error hiring a contractor without the necessary skills to pour her a new driveway. He has done a great job doing all kinds of interior renovations, but I don't think he knows what he is doing with this and I need some professional advice before I mention this to my friend. He removed all the old concrete and then he drilled into the house foundation and insterted rebar into the holes. In the next day or two he will be filling the driveway with concrete. I worry that the driveway will shift and pull the foundation apart. She lives in British Columbia, Canada (similar climate to Seattle).

    Anybody out there have an thoughts on this?

  2. #2
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    Default Re: Concrete Driveway Rebar placement?

    I do this all the time to prevent the slab from heaving or settling at the garage door or house door. I use smooth dowel with one end greased so that the slab can contract freely. Ideally the rod should go into solid or filled block at the house.

  3. #3
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    Default Re: Concrete Driveway Rebar placement?

    Marge ... out here on the prairies we would never pin the driveway slab to a foundation mainly because of our extreme winters and severe frost heaves.
    I'm not not sure what the common practise in your area is ..... doesn't sound like you live in the interior..... if you live in Van . or the sourrounding areas or even on the Island this may be a common practise.

    You could call a local concrete contractor or the building department to make an inquiry if this is common in your area.

    Just a thought.
    "" an ounce of perception -- a pound of obscure "
    - Rush

  4. #4
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    Default Re: Concrete Driveway Rebar placement?

    Quote Originally Posted by ed21 View Post
    I do this all the time to prevent the slab from heaving or settling at the garage door or house door. I use smooth dowel with one end greased so that the slab can contract freely. Ideally the rod should go into solid or filled block at the house.
    Thanks for this, Ed. I feel slightly better, although I just came back from inspecting the job myself and there are other concerns as well.

    When removing the old driveway, he damaged a drain pipe that runs out from beneath the garge floor-it now has a hole. The question is-is it big enough to be filled with wet concrete?
    Click image for larger version. 

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    The rebar is suspended on the outside edges of the pouring mould but the rest is just laying on the ground. I have no confidence this guy knows what he is doing. (see attached images)


    Click image for larger version. 

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    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  5. #5
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    Oct 2008
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    Default Re: Concrete Driveway Rebar placement?

    Quote Originally Posted by canuk View Post
    Marge ... out here on the prairies we would never pin the driveway slab to a foundation mainly because of our extreme winters and severe frost heaves.
    I'm not not sure what the common practise in your area is ..... doesn't sound like you live in the interior..... if you live in Van . or the sourrounding areas or even on the Island this may be a common practise.

    You could call a local concrete contractor or the building department to make an inquiry if this is common in your area.

    Just a thought.
    Thank you fellow Canuck! I have spent most of my life in colder parts of Canada so I thought this idea of pinning the driveway slab to the house was looney. Here in Abbotsford we almost never get frost, however, we are on an earthquake faultline. See the last thumbnail in the comment above to see what he has done with the foundation and the rebar.

  6. #6
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    Default Re: Concrete Driveway Rebar placement?

    The rebar into the foundation wall is not what I was talking about. I was talking about smooth dowels 2 ft long with half in each. Contraction should be allowed for.
    The rebar should be above the gravel. Half way or so.
    Don't know what the pipe is, but it should be patched.

  7. #7
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    Oct 2008
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    Default Re: Concrete Driveway Rebar placement?

    Quote Originally Posted by ed21 View Post
    The rebar into the foundation wall is not what I was talking about. I was talking about smooth dowels 2 ft long with half in each. Contraction should be allowed for.
    The rebar should be above the gravel. Half way or so.
    Don't know what the pipe is, but it should be patched.
    Thank you for trying to help. I've brought my concerns and your suggestions to my friend, but she is so sure her contractor knows everything about everything that she just got mad at ME. They went ahead and poured the concrete this morning. There's just no helping some people!

  8. #8
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    Chicago
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    Default Re: Concrete Driveway Rebar placement?

    I know I'm a day late and a dollar short, but here's what I see from the pictures:

    The rebar is elevated on the forms. It's laying on the ground towards the middle because it's just the layout in prep for the pour. If it were us, I don't know how things are done elsewhere, but if it were us, we'd raise the rebar as we pour and set it in the concrete. I can't think why you'd go through the labor and expense of raising it in the middle before that for a residential driveway. We'd also pull the rebar through from the foundation and make a joint so the slab wouldn't float independently any which way it wanted.

    The drain pipe is another matter. I'm hoping that was fixed before they poured.
    Last edited by Hatsephsut; 11-09-2008 at 12:43 PM.

  9. #9
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    Oct 2008
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    Chicago
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    Default Re: Concrete Driveway Rebar placement?

    But - and I'm not arguing just trying to relieve the poster's anxiety; all of that isn't always necessary in every pour.

    Rebar alone should be ok for this application if they didn't do more that you didn't see before they poured. It's not an area that's subject to constant heavy traffic or is a structural element of something else.

    I can't tell if they have saddles or not but a driveway pour goes hard and fast, it has to. It might have been more reasonable for your friend's circumstances not to install them than to incur the labor and material expense and slow down the pour to work around them.

    If they bid on the job including all of this and didn't do it that would be a big problem. If they explained all this to your friend and she accepted it, then I wouldn't worry too much about her.

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