We currently have the drain pipe from our bathtub and sink going into the drain pipe from the toilet before it connects to the main drainage stack. Im pretty sure this is not acceptable. We are going to change this and connect the tub and sink drain pipes directly to the stack. I was wondering if the tub and sink pipes are required to be connected to the main stack above the toilet connection. Also, we are thinking of setting up a sewer pump in the basement so we can add a bathroom in the basement. Are there any special requirements as to where this pipe should connect to the main stack?