I just had a concrete patio poured and about two days later, after the first rain, small holes started appearing in the surface - pinhole size up to about 1/8 inch. By each hole is a dark streak. I thought at first that these were small pieces of dirt and I could wash them away, but the dark streak is a stain on the concrete. It looks like something is just below the surface of the concrete and it pops through the surface like a pimple, leaving the streak.
I'm beginning to wonder if they are small pieces of iron or steel, and are rusting out and breaking through the surface. Has anyone here ever seen anything like this?
I'm beginning to wonder if they are small pieces of iron or steel, and are rusting out and breaking through the surface. Has anyone here ever seen anything like this?