OK to vent only through main stack in a small bathroom?
Hello,
I will be totally gutting and redoing my home's only bathroom next month and am trying to iron out any problems now before I start ripping things apart. I have a few questions about the best way to do things...
The main waste/vent stack is cast iron, and runs vertically through the corner of the room near the toilet. Here is a picture where I cut the floor and wall open to check things out: http://img404.imageshack.us/img404/3863/stackrw5.jpg
That big horizontal part goes over about a foot to the toilet. Reaching my hand in, I can feel some threaded pipe coming off that with a PVC connection. I cut the wall open behind my vanity, and saw PVC running from the drain, down the wall, and across the floor towards the toilet. The same goes for the shower. Here is a crappy not-to-scale floor plan: http://img119.imageshack.us/img119/6...oorplantw8.jpg
My first question is about venting. Currently, nothing is vented at any of the fixtures. The drains for the shower and vanity both run straight to the toilet drain with no vent anywhere along their lengths. Is this OK?? Are they close enough to the main stack to be vented by that? The bathroom is small (6'x7') and both fixtures are within 6' of the stack.
Secondly, I will be moving the toilet across the room during the remodel. This requires extending the current drain about 5' along the joist cavity (no need to cross any joists). I was disappointed to see all that cast iron! Is there any way to extend from the existing cast iron drain without cutting into the stack and replacing with PVC? If not, I guess I would cut about a foot above and a foot below the floor and replace with PVC using those neoprene banded couplings? I'm afraid to use a snap cutter on the old, brittle cast iron... Any recommendations on sawzall blades or other cutting methods? Searching these forums I heard angle grinders work well, but I don't think I could get all the way through the pipe with one... Also, are cast iron riser clamps (mounted to the framing) sufficient to hold the stack while I cut and remove a section?
The current supply lines coming up from the basement are 1/2" copper to feed the whole bathroom. When all is said and done I will have a single sink vanity, toilet, and standard 5' whirlpool tub/shower. Would it be prudent to run 3/4" up instead or will 1/2" be enough?
Hope I have given enough info... Thanks so much guys! :D