Why Is My Concrete Stained? 

It’s natural to be concerned if you have exposed concrete in your basement, or even outside, and you’ve noticed stains appearing out of nowhere. These stains are ugly and can indicate hidden damage in your property. Concrete must be correctly mixed and proportioned if it is to perform to its maximum potential. However, a small imbalance might cause concrete to deteriorate over time in a superficial or cosmetic fashion. If your concrete was correctly mixed, placed, and cured but is still staining, the cause is most likely damage or poor environmental conditions.