Generally seams hold up very well. From time to time the seam fails and one side falls leaving the seam uneven and loose. Most often this failure happens when seams are placed in the middle of the sink. To complete these repairs we stabilize the granite by adding additional supports between the top of the cabinet and the bottom of the granite. Once this is done we use high grade stone adhesives that we color match with the countertop as best we can to reset the seam. Most of the time resupporting the granite brings the seam even. In situations when it does not we diamond grind the countertop on the high side of the seam, once the seam has been reset, to make it completely smooth and even. Once it is even we repolish the affected area to make it look like we did no work at all.