Looking to add a 2nd floor bathroom (shower, toilet, sink). Existing home has bathroom on 1st floor with cast iron pipe drains. Would like to get some info as to how to plumb new PVC drainage run into existing cast sewer pipe, as well as venting into existing stink pipe.
You can NOT connect the 2nd floor waste lines into the existing stack on the 2nd floor.
To do this job you will have to run a new stack inside the wall(s) and connect to the old stack *below* the lowest 1st floor fixture. If your town will allow 3" PVC (not all will), you will at least have an easier time of it.
The top of your new stack can tie back into the old one to avoid having to punch another hole in the roof.
Pick up a Basic Plumbing book that shows remodeling jobs. There are many good books that will show exactly what to do.
Jim
In addition to Jim's comments, I would recommend picking up a copy of "Code Check Plumbing". I found this to be an excellent resource when I put a new bathroom in my house several years ago.
See if there is a clean-out WYE in the basement. If you're lucky, remove the clean-out and connect there. Otherwise, you have to cut the cast iron AND support the weight of the stack. You really can't remove all the cast iron as there will be vent connections buried in the bath wall.
With the stack supported, you can splice in a 4" PVC WYE using Fernco couplings. Spend some time making a plan to fabricate a support...
Jim
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