Block foundation wall question

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Uncle Buck
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Joined: Tue Aug 22, 2017 6:01 am

Block foundation wall question

Post by Uncle Buck » Wed Oct 11, 2017 6:36 am

Hi
I'm adding a den addition behind my attached garage and have some concern about the existing foundation wall. It is currently hollow 8" block 1.5m from footing to top of wall. The garage slab is 0.1m below the top of wall. The addition will have a full basement so this existing block wall will become a basement wall. Since the finished floor of the addition is 1.0 m above the top of this block wall, it leaves the wall with no lateral support once the excavation is done. I believe the code says an 8" block wall with no lateral support can only have 0.9m of fill against it. Mine has 1.4m to the top of the garage slab. My design firm has done a sketch under an engineers seal that instructs me to fill each block void with 20mpa grout and 10m rebar on 8" centres.

While I recongnize this will strengthen the wall, it still provides no lateral support.

Thoughts on this design?

I was considering drilling long holes through the top row of blocks into the slab and pinning it with rebar and epoxy to provide some lateral support. Not sure what spacing I'd go with.

Would this be overkill?


Clarence
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Joined: Mon Mar 27, 2017 9:15 am

Re: Block foundation wall question

Post by Clarence » Wed Oct 11, 2017 7:14 am

Maybe look at using a Buttress you only need one every 20 Ft.

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Shannon
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Re: Block foundation wall question

Post by Shannon » Wed Oct 11, 2017 7:20 am

well the grout and rebar once cured should give you the strength they are looking for IMO.
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Uncle Buck
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Re: Block foundation wall question

Post by Uncle Buck » Mon Oct 16, 2017 6:21 am

Thanks folks. Ultimately decided to epoxy in 5 12" rebar as pins. I figured an hour and $30 in materials, it's cheap insurance.

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Shannon
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Re: Block foundation wall question

Post by Shannon » Mon Oct 16, 2017 6:44 am

sounds good
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