I'm planning to install a three piece bathroom in the basement. We have 2.5" and 3.5" rough in pipes sticking out, while 2" pipe was fully in the concrete. I had to break the floor to see if it was actually a pipe cap. We are not the first owners, so we don't know why contractors buried the 2" pipe like that. Is this a normal thing to do? Could it be cause previous owner wanted only 2 piece bathroom? As well do I need to make sure all pipes are connected and vented under the concrete or must it have been done correctly under the code anyways? We are in Canada.