# Concrete Patio Help!



## Jono59 (Aug 18, 2018)

So our concrete patio was poured about a year ago and as you can see in the pics it is now uneven in one area? Wondering if one side is sinking? Or one has raised up? Anyone with experience got any ideas for me? Reaching out to the contractor but wanna have some insights before they come out. Thanks


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## Tsmith (Aug 11, 2017)

Sure looks like the one side is sinking. Can't imagine the other side rising from anything underneath that quickly.


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## adgattoni (Oct 3, 2017)

Could be that they didn't add enough subbase before pouring the slab, or they didn't compact it well enough.


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## RayTL (Jun 4, 2018)

Any drainage nearby?


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## krusej23 (May 8, 2018)

There are companies that will lift slabs like that with pumped in foam underneath. You could check into something like that if the contractor doesn't do anything.


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## Jono59 (Aug 18, 2018)

No drainage nearby, however it does appear that the ground underneath the lower section has eroded away some. Contractor set to come out tomorrow to have a look...


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## Chak (Jul 2, 2018)

krusej23 said:


> There are companies that will lift slabs like that with pumped in foam underneath. You could check into something like that if the contractor doesn't do anything.


They refer to this as "mudjacking". I assume this is what your contractor will recommend. My neighbor had this down and it seems to have worked pretty well. I watched when it was done and they essentially drilled holes through the slab and pumped additional concrete under the slab to lift it.


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## Neiltsubota (May 15, 2018)

Two things could be happening, One side may be sinking, or One side may be raised from water, snow, or ice. If it is only one year, I tend to agree with the others that the "sub-base" material was not prepared properly....Compaction, 3/4" minus rock, sand mixture, and all watered down to a compact area, before forms are set, and re-bar/wire mesh with supports.


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## Wolverine (Jan 17, 2018)

Are you in clay?


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## Jono59 (Aug 18, 2018)

Yes we are on clay. Contractor is going to come back and take out the two sunken sections, compact the ground which he said he didn't do as the ground was already hard... &#128527;. Repost but also drill into existing concrete pads and install rebar so that the new pour is attached to the existing??? Will see how that works out... &#129335;‍♂


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## Wolverine (Jan 17, 2018)

Up here in Michigan the cement contractors usually dig out the clay (12") then fill with sand, then compact. Clay will heave and move much more than sand and shouldn't be used as a sub base.


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## marklouisg997 (2 mo ago)

I asked my recent concrete contractors and said this could easily be fixed. However, they assured me that this wouldn't happen to my patio because they didn't used clay.


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## berisiw (3 mo ago)

Jono59 said:


> So our concrete patio was poured about a year ago and as you can see in the pics it is now uneven in one area? Wondering if one side is sinking? Or one has raised up? Anyone with experience got any ideas for me? Reaching out to the contractor but wanna have some insights before they come out. Thanks
> 
> 
> 
> concrete sealing st louis


Hi, I am having a contractor add a new cement slab for my backyard patio. Approximate size is 500sqft (13x39) I had a couple questions for the experts on here before he starts the work: 1. What are some affordable add-on options to make the slab a little bit more decorative and textured ? (ie: stained, stamped, etc...) 2. How can I ensure that the slab doesn't crack after installation? What should I make sure the contractor do to prevent this? 3. If I plan to add a pergula or roof over the concrete in the future, what do I need to make sure the contractor do? 4. Are there any other important questions I should ask the contractor before he starts work? THanks very much for your help!


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## CLT49er (Jun 19, 2020)

I had a stamped concrete patio installed this year. Love it. Two things I have an issue with. It gets super hot in the summer because of the dark color I have, I think. And mine is very slippery when wet but this is correctable with another sealant with some grit added to it. I also like that they used solvent based sealer so reapplying a sealer is super easy.

If you plan to add a structure on top they will need account for that.

One thing I like what I did was to add a drain / air vent for smokeless firepit / potential to add on a gasline. Its under my firepit. Just a pvc pipe.


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## theycallmePops (2 mo ago)

Jono59 said:


> Yes we are on clay. Contractor is going to come back and take out the two sunken sections, compact the ground which he said he didn't do as the ground was already hard... &#128527;. Repost but also drill into existing concrete pads and install rebar so that the new pour is attached to the existing??? Will see how that works out... &#129335;‍♂


Some regions have expansive clays that can vary in volume significantly with varying moisture. However, the general piedmont area of North Carolina, South Carolina, and upper Georgia has clay that is relatively stable. I would guess that even if the soil seamed hard the contractor did not probe it. You photos appear to show differential settlement of the soil. That is a significant amount in one year.

Doweling into the adjacent slab is a good idea. However, they would be better to use smooth bars rather than rebar. Smooth bars will allow for seasonal lateral movement of the slabs.


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