Concrete advice

[Flatblackratrod]

I previously posted about a concrete issue on a new pour (delamination you can see details here https://www.garagejournal.com/forum/threads/delamination-on-new-pour.502108/

Long story short my concrete contractor ended up cutting the slab away from the footings as best he could and repoured the slab.

There is a definite crack/slight elevation difference between the footing and the slab the slab being higher. Curious how I would go about trying to get the slab and footing at the same elevation. I was thinking some sort of self leveling substrate on the footing area. The different at the largest difference is approximately 1/2"

 

[Flatblackratrod]

Also forgot to mention this isn't a case of settling. It was apparent almost immediately after things started to cure. At that point I was tired of fighting and was looking ahead on the project.

 

[Ricky Joe]

Make a paste of Portland Cement and trowel it in.

 

[ConCretin]

That's pretty significant shrinkage and possibly a bit of curling. Whatever the cause, your repair method will depend on whether or not the crack continues to move. The shrinkage crack probably won't move much once the concrete has fully set but movement from the curling could possibly continue.

Curling isn't usually an issue in smaller residential slabs but if the vertical movement occurred after the slab was placed, it's likely the cause. Curling occurs when drying tension occurs in the top of the slab while the bottom remains moist due to contact with a vapor barrier or soil. The tension causes the edges and corners to lift up. It's possible the curling could relax and reoccur with seasonal changes.

With all that said, I'd grind the surface flat, use a crack chaser to clean up the joint and fill it with a flexible polyurethane caulk. This would allow for some movement and clean up the aesthetics. I'd advoid rigid repair materials and thin overlays since any movement will crack and dislodge them.

Sorry this been such a challenge but you're getting closer to finally enjoying your new shop.

 

[Flatblackratrod]

Super helpful information here guys appreciate it. I honestly didn't know that curling was a thing in concrete so I had to look that up. That said I did find some photos I thought I lost where you can see they poured the slab slightly higher in the area where the biggest discrepancy between the footing and the slab are. So I definitely think this is a case of shrinkage. In hindsight I wish I would have had the contractor go back and cut a straight relief where the footing and slab meet. Here is the photo (or rather screen grab from a video) pre shrinkage you can see where the slab goes over the footing.

 

[duneslider]

What is your intention with the final floor? If you are planning on some sort of fancy finish like epoxy I would wait and discuss with the contractor doing that work. If you are just leaving it bare concrete what LL said is great.

 

[Flatblackratrod]

What is your intention with the final floor? If you are planning on some sort of fancy finish like epoxy I would wait and discuss with the contractor doing that work. If you are just leaving it bare concrete what LL said is great.

Nothing too fancy with the final finish I am going to stain and seal with ts210. Professional epoxy is out of the budget at 1440sqft. I like LL's solution. To be honest what is most likely to happen for me is I will continue to look at it for the next couple weekends while doing other tasks on the shop (paint gutters etc.) It will finally get warm I will get over ambitious and I will jump the gun and stain and seal then move all my stuff in and around the perimeter of the shop and pretend like it doesn't exist... Smile and go on with life!!

 

[duneslider]

Nothing too fancy with the final finish I am going to stain and seal with ts210. Professional epoxy is out of the budget at 1440sqft. I like LL's solution. To be honest what is most likely to happen for me is I will continue to look at it for the next couple weekends while doing other tasks on the shop (paint gutters etc.) It will finally get warm I will get over ambitious and I will jump the gun and stain and seal then move all my stuff in and around the perimeter of the shop and pretend like it doesn't exist... Smile and go on with life!!

I was gonna say that is how I would handle it but some people on here are way more particular about their concrete than I am. I've never seen a perfect concrete job but have seen some really nice work on commercial jobs and I know what those jobs cost so I also understand what I am getting with a dude in a pickup for the price I am paying.