Asked on Aug 25, 2020
How to remove dark spots from new concrete patio?
by
Ed DiVecchio
+15
We just had a new concrete patio poured yesterday morning. I asked the contractor before he left if we needed to worry about rain. He said no. It did start to rain shortly after they left. It didn't rain long. But after the rain was done, we noticed spots all over the patio. We contacted them and asked if this would go away. They said it was moisture spots and should go away. Today, the patio is much lighter as it is drying, but the dark spots have not gone away. Does anyone know what these are and if they will go away? Just didn't know if this was something I should have the contractor address or not. I don't know concrete, but this is ugly. Thank you ahead of time.
It where you have excess moisture from the rain. It should dry eventually but will take longer in the spots.
There are good tips on how to clean a cement patio in t his post from DIY Network.
This video also shows how to clean a cement patio. Good luck!
Power wash it but wait until the concrete drys. Did your contractor tell you to keep the patio wet for a few days. You should so it does not crack
Hello Ed
Here is some info
https://www.concretenetwork.com/fix-concrete-cleaning/
Ed: they are probably more noticable for you -- because of paying for the work. I think time will "age" the concrete --- if you simply do the cheapest thing: nothing.
I would give it a month or so to cure. Meanwhile, I would have a friendly conversation with the contractor about your concerns and keep a record of the contact, along with the written agreement you have. If the spots remain noticeable, I would again contact him, and follow up in writing. I am hopeful it will resolve. Don't make any attempts to change the concrete until you are done with contacting the contractor or I have no doubt he will blame you. Good luck and stay safe!
I'd give it more time to dry before making a final decision. Looks like just water spots to me that will dry up. We had a concrete floor poured this year to be used to hold a hot tub. It took almost a month for a wet spot in the very middle to dry and disappear.
Kathy Gunter Law and Cynthia H have the right idea. Just keep in touch with the contractor on the progress and document everything. Here are some reasons.
https://www.ehow.com/info_12197744_cement-dark-spots-drying.html
I think it's going to take a few more days for the water spots to cure, but I would definitely keep in touch with your mason in case it doesn't.
Thank you everyone. I appreciate all of the helpful feedback. After several days of rain, the patio is almost back to normal. Just glad the spots are almost gone. Thank you again.
To me it looks like the rain washed away a bit of the topping on the slanted edge revealing the aggregate..... so you may need them to come back if it doesn't dry out in a couple days.
I don't think it is a issue.. it is just the way it was finished and your pictures seam to be super zoomed in
If it was just yesterday, you should wait until the concrete is cured completely which could take up to a month. If they're still there, call the contractor back.
Hi, here's a link that gives some information about concrete spots and stains. https://www.concretenetwork.com/concrete-discoloration/#:~:text=For%20more%20severe%20discoloration%2C%20try,enough%20to%20remove%20the%20discoloration.
I hope your stains go away once the concrete has cured properly