I noticed my trailer was leaking a little water out of the bottom of the toilet. When I took the toilet off It looks like there was not a seal on the bottom and that the hole is about an inch below the floor level. This is my first RV and I am not sure where that is supposed to be. In a house I know it is supposed to be above or close to even with the floor, is that true for an RV as well? If so, do I just raise it like I do a house toilet flange with an expander?