Warranties

I live in North Carolina; What is the length of time covered by law a new home contractor is responsible for defective workmanship? My builder installed two layers of tile on the shower floor and now I have a water problem. I'm told that this should not have been done and is not industry standard. The flooring will have to be torn out and replaced. The house is 4 years old. I have been told a builder is responsible for defective work for 12 years, is this correct?

I have an automobile that experienced a problem while still under warranty, but because I was on a long trip, I wasn't able to report the problem to my dealer until the warranty had expired. I have documentation for the fact that the problem occurred under warranty, yet my dealership has denied that the problem is covered under warranty. Am I covered?