I had a sewer guy out to clean my floor drain. He said he couldn't do it because he hit clay and told me that the trap had rotted out and needed to be replaced. This will involve busting up concrete and moving a "assembled" shower off a cement base in order to get to the pipes. Someone please tell me what does it mean that the guy hit clay? Does that mean there is something wrong with the pipe?? I am very anxious for answers. Someone help fast.thanks. HelenAg