Q: We discovered hairline cracks in the ceramic floor tiles in my 3-year-old house. The longest crack runs from the living room (eight tiles) in a straight line to the adjacent breakfast room (three) ...

Q. About one year ago a plumber installed a granite vanity top with a porcelain under-mount bowl in my bathroom. This week a hairline crack 6 to 7 inches long, beginning at the drain area, appeared.

Q: We installed porcelain tile in our hallway and kitchen 20 years ago. Over the years, one or two tiles in the kitchen have developed hairline cracks. When we remodeled our kitchen five years ago, we ...