I am relocating my second floor bathroom to an adjacent room. My main drain stack runs up vertically in one corner of the new bathroom. While my toilet and bidet which will be located side by side along the drain stack(that vents through my roof) and can be vented with a conventional loop, my shower/bath and sink are on separate walls which to not allow me to run vents back to main stack/ventilation pipe. Q? Are sink and bath vents necessaary if I use 2 inch PVC pipe for drains

Under my Code, every plumbing fixture has to have its own vent. Yes, vents are necessary to assure proper drainage and venting of sewer gases.

Definitely need a vent for sink. Tub shower may be wet vented,(still vented) depending on your settup and code. Can you give us some detailed pictures of what your setup is.

As MIlo stated, every fixture must have a trap, and every trap must be vented, one way or the other.

Hi Goebir..

Sorry to say that you will definitely need a vent for the sink and bathtub if you want the fixtures to drain properly. Not only will tub and sink make noises while draining without a vent, but traps can get siphoned and sewer gasses can escape into the home and that really stinks... literally!

All plumbing codes also require a sink and tub to be vented.

In this case you may be able to run a 2" VENT off the toilet drain and run that 2" as a WET VENT for the lavatory and then pick up the tub drain off that pipe. Then that 2" pipe would need to run 2" above the floor, stubbing out 1.5" for the lavatory and then running the vent full size 2" up and through the roof (if you can't get back to that 4" stack).

What I just described can be referred to as WET VENTING...it may or may not be legal in terms of plumbing code in your area. You would need to check with local plumbing inpector to know for sure. Otherwise you will need to run an INDIVIDUAL VENT for each fixture.

Let me know what you think...

MARK