I poured a small slab. I made a mistake, there is a small low spot and water pools.

Can I float patching compound to raise the section?

I also have some rough edges. Will filling in with patching compound hold up?


If I do either of these things, will patching compound blend in?

Thanks for any advice.

 

Concrete does not bind well to cured concrete and especially if it's a thin coat and even worse if it's outside with freezing conditions.

There are epoxy coatings that would work better but they are thin and not really intended to be levelers.

You could tile the structure but again freezing conditions will take their toll!

 

If it makes a difference, the slab hasnt cured, I poured it yesterday.

I have quickcrete vinyl concrete patcher and I filled in a rough edge with it, will regret the color difference? .Can I expect fresh readymix concrete to dry grey?

 

Maybe not, but my bet would be that, in the end, you'd be more disappointed with a "fix" than with what you have now. I have seen a few floors that I believe were within a very few thousandths, but those were highly skilled crews. Or sometimes the concrete will be coated with hard product that is then ground. Either way, they were not run of the mill pours, and required a pretty think wallet, I'm sure. Otherwise, it happens sometimes, even with experienced crews, so my suggestion is to chalk it up to experience and continue on with the project. As far as the low spot, it's a matter of getting it screeded well and be sure that it's all concrete and that you're not just moving the cream around on top, and that you are consistent when you trowel. On the rough edges, vibrating will obviously get it worked down good, but for your own work you can jiggle it down with a shovel and then walk around and tap around the perimeter of your forms with a hammer to get it tight. As you know now, just remember to not assume that it's going to flow up evenly to the forms.

 

Actually its not a floor. Its a small slab outside and doesnt need to be level, rather just have the proper pitch i need. It does has the slope I want, other than the small impression that is collecting water. By the time I realized it when finishing it, it was too late.

Another idea....

since it is sloped, how about grinding it? Perhaps fill the impression with water and sand off just enough forwater to flow.

However, I only have a small angle grinder and not sure how to go about it.

I can worry about the color later when it cures.

 

Depending on where the dip is you could cut expansion joints through the dip to allow it to drain away.

 

I was thinking like X, cut an expansion joint where the dip is and it will channel the water off of the slab. There shouldn't be any issues with filling the voids on the sides of the slab.