Wanting to move the 3inch drain above the floor joists. I have a closet flange that goes into a riser, from the riser it goes into 3"x3"1.5" dwv for the sink. Could I cut the length of the riser so it will be above the floor joists? Or could I go with a closet bend and tie into the sink drain further down. Or could I use a 4 inch pipe?