Q: Tim, can you solve a conundrum for me? My bathroom was remodeled about two months ago, and the vanity has a granite top with a china under-mount sink. Yesterday, I noticed a long crack in the sink that extends up from the drain hole. The contractor claims I did it by dropping something. I didn’t. He won’t repair it. What can be done? How might it have happened? I feel I need a new sink, but I can’t figure out how to install one because when I lay on my back and look up I don’t see any clips holding the sink to the underside of the stone. I’m so angry at the contractor. Help! — Paula H., Fort Lauderdale, Fla.