Here's some of the nastyness coming down the wall, see that odd, rubbery looking white compound? Yeah, that's what the subcontrators called a "joint." I think they were smoking a joint when they put this together.
So basically, what happened is this: The subcontractor that did the kitchen build out cut some major corners. This is not even REMOTELY close to being up to code. The drain pipe coming out of the wall (concrete walls and floors) is metal. It's an 1.5" round. The drain coming out of the sink/disposal is made of PVC pipe. It's also 1.5" round. The metal pipe has threadings on it, and a metal nut at the end, which you would use to secure the drain pipe to the wall pipe, if you were using all metal. They butted the PVC pipe up against the wall drain pipe, and squished the rubber putty around the two pipes.
I swear, that's really what they did. The pipes are the same size, so it's not like one fits into the other one, creating a seal or anything. They just put the two pipes up against each other and covered it with some goo.
What really pissed me off is that after all was said and done, I fixed it for $6.43, two trips to Home Depot (where I met my new best friend, Larry, their plumbing expert), and 3 hours of diagnosis, labor and running around. That's all it took, and I know very little about plumbing (although clearly more than the clowns that did the job in the first place).
Of course, this was not exactly an entry level project, but I was not the least bit scared of ruining anything, afterall, their cockamamey set up lasted the last two years, so honestly I couldn't do worse!
Since I know how to measure and cut out the dry wall, shut off the water main, and employ common sense, I was good to go! I feel really accomplished, Paul is super relieved (and who wouldn't be? That's a huge bullet we dodged by catching it early and fixing it ourselves), and we're using the fan to dry out the soggy MDF and drywall back there (at least the portion we can see....but under the sub floor is concrete, so no worries of passing it on to the floor below us).
Here's a video of the final result: