we're having our bathroom remodeled. It's almost done, couple of the decorative mosaics are misaligned, the shower pan doesn't drain properly. The water collects in one corner. The contractor's answer was, that the house moved. It's a wooden structure, with crawl space. We live in Calif. so far haven't heard about an earthquake recently. I was just wondering if it's really possible in a wooden structure to find about 2 inch shifting. Does anybody has an answer for this?

Thank you.