We have a new house with a basement floor issue; our builder let it flood, and sit, several times with muddy water and how, even after it was pressure washed, a brown stain remains on the concrete. I've tried a small spot with muriatic acid, without any noticeable difference. Anyone help? Thanks, frank
Re: Basement stain
Try a solution of TSP + powder laundry detergent mixed in warm water.
If the stain is still there, try bleach (make sure the area is ventilated, or you end up sick).
Please report back.