Moving 1st floor bathroom

[VinR]

We currently have two bathrooms, 1 directly above the other, which both use a common stack vent. The top bathroom toilet and tub T in to the stack, no other vent. The bottom floor toilet and tub use something that I think is called a trumble? basically a big piece of cast iron with 3 inlets. No other vent.

After reading this forum and a book it seems like the bottom bathroom venting would no longer be allowed. If I move things in the down stairs bathroom am I obligated to to add a vent?

By move, I am going to be keeping the same distance between toilet and stack, but extending the shower/tub from 2 feet away to 5 feet.

Thanks,
-Vin

 

[hj]

There is no way to answer your question without actually seeing what you have.

 

[Sponsor]

 

[VinR]

I hope this helps. This is the current drain/vent system for our 2 story house. The 1st floor bathroom is the one I will be moving around a bit.