As a concrete contractor who specializes in high tolerance and super flat floors, I usually found the owner and general contractor to be ecstatic with the finished product on the day I poured and finished my floors. I would, in most cases, get paid in a timely manner. But about half the time, anywhere from 6 months to a year later, the floors would show excessive curling, cracking, shrinkage, and sometimes joint rocking. I was beside myself trying to figure out what to do to get the long-term characteristics of my flatwork to be similar to the day I poured it.