Remodeling night mare

[dan1925]

I am enlarging my kitchen and have two (2) primary issues. 1st, I want to remove the 12" drops that are supporting my old cabinets, however when I began removing the drywall covering the drops I discovered that all of the drains for my upstairs full bath are located inside the drops. I am not a plumber so I am uncertain about what option/alternatives I have. 2nd, My home was built about 30 years ago the primary drain pipes for both my full & 1/2 baths are 4" cast iron. The reason I mention this is because I recently had to replace a 10' section of the cast iron pipe in my basement because of a septic smell. When I began searching for the problem I found a 36" crack in the top section of the pipe. I replaced the defective section with a 4" piece of schedule 40 PVC problem resolved. However, now that I am in the mist of this remodeling adventure I have discovered another issue with the same smell when I opened up my kitchen walls. I still haven't discovered where the problem is but I'm assuming that it's another issue with the cast iron piping. Is this a common problem with cast iron pipe and if so should I replace all the cast iron piping at this time since it is all exposed? Any advice someone could provide sure would be appreciated.

[pushkins]

The "drops" you refer to I assume are soffits (dropping down from the ceiling right above the cabinets ?).
Simply there are two options for you, reroute the drain lines back into the wall cavity or leave the soffits in place and work around them. I always like to see the plumbing in the walls and I have a huge dislike of soffits.
The problem you face is the work involved to actually get the drains to the wall cavity might be much larger project than your up for. Sometimes it can involve removing part of the ceiling drywall and cutting or drilling a path through the ceiling joists. This should not be done unless you are well aware of what your doing, you just cannot cut a hole anywhere in a joists.

If you could post a picture of what you have it would be helpful.

If the cast is a problem and the wall is open , replace it now, it's obviously much easier to do it now.

[Electrician Wannabe]

Instead of replacing the cast iron with PVC you may wish to consider replacign with no-hub cast iron. One thing you may notice now that you have a 4 foot section of pvc in your stack is that you can hear the sound of water flowing through the stack everytime a toilet is flushed. Cast iron is a great sound insulator.