How to clean stains on new concrete?

[El VMX]

I poured a new patio yesterday afternoon and it rained overnight before the concrete was fully cured. The runoff from my house stained the surface. It's only been about 20 hours since I finished the pour. I tried scrubbing it with a brush and water but that didn't help much. I've used Oxyclean on concrete before with good results but I'm worried it will discolor the new patio.

If I use it, should I do the whole thing so the color changes evenly? What else can I try? Has anyone else had this happen to them?

 

[ChicagoDogz]

@El VMX don't worry, it's definitely fixable. Right now, your concrete is incredibly fragile, and scrubbing it can do more harm than good.
The stains are likely a mix of dirt from the runoff and efflorescence, which is a white salt that comes to the surface of new concrete.
the best thing to do is wait a few weeks until the concrete is fully cured (28 days is a good rule of thumb). A lot of times, with a few good rainfalls and a little sun, the stains will just fade away on their own

 

[stev3njr]

@El VMX yep, the comment above is right. The absolute best thing you can do right now is nothing. Your concrete is still in its infancy and scrubbing it can damage the surface and create permanent color differences.
The stains you're seeing are a combination of dirt and efflorescence, and a lot of times, the efflorescence will disappear on its own with a few good rainfalls and some sun.

 

[speed fighter]

You can use Oxyclean, it's Sodium Percarbonate or a similar oxygenated cleaner, but with caution. If you use a chemical cleaner even a mild, one you should clean the entire surface, or at least from control joint to control joint. This is to maintain a uniform color and texture across the entire slab. Cleaning a small, discolored spot may inadvertently leave a new, cleaner spot that looks just as bad.

 

[El VMX]

Thanks! It did work. I was also hesitant in scrubbing it. I am now seeing a huge difference. Can someone recommend a good concrete sealer?