As part of our pool construction, we had pea gravel concrete decking installed. In one area of the decking, we are getting rust spot formation. Here is a pic:
The spots are too large to be re-bar or re-bar ties sticking up out of the concrete. Any idea what this may be. It has seemed to grow in size over the last few days.
The decking is approximately 4-1/2 months old. Thanks in advance.