I am in the middle of a large scale bathroom renovation in a 1950s second floor over/under garden style condo. The units were renovated poorly in 85' and some of the 1950's stayed when they shouldn't have.
Here is my dilemma:
I have re-plumbed the whole condo's supply lines due to very poor original installation. I Installed 3/4" supply lines to the bathroom shower/tub area to feed a Kohler Mastershower setup with for overhead rain tiles. In conjunction to the rain tiles there are 4 body spray tiles and a husband/wife opposing showerhead.(depends on relationship) I wanted to install a shower pan with linear drain but I got vetoed by the powers that be for the resale value considerations.(this is the only bathroom) So I installed a new tub... After trial runs of the shower setup which is incredible I noticed that the drain is slow. This was a problem 6 months before the remodel at which time I had a pro snake the drain and then it drained like a champ. I decided to pull the tub again since I have not installed the onyx shower surround yet. The tub drain is through the concrete floor and appears to have been roughed out with a sledgehammer. There is a foot and a half between the floor and my downstairs neighbor's cieling. The pvc p-trap is tiny 1-1/4", at first glance this seemed to be the problem until I looked under the floor. Under the floor is 1-1/2" pvc running into a threaded pvc reducer into a threaded steel pipe then into a female steel or, cast iron ~60 degree pipe... So I got out my phone to take some pictures and get a better look. This pipe runs to a sani tee and then off to God knows where between the floor and the ceiling. So, I took another picture straight down the pipe to the steel union after I got antsy with my sawsall. This looks like it reduces down almost a half an inch!
It looks like there is not much I can do other paying of my downstairs neighbor to demo his ceiling and put in 3" drainage. But I need to exhaust all other options first.
I need to fix this as best as possible before I cover this up with a tub and never see it again. Frist, I am getting a pro in here to scope and scrape the pipe all the way to the 4" poop chute, then rebuild. I have started purchasing by getting a Kohler Clear-Flow brass tub drain and thought to couple it with a 2" P-trap (2" to hold more crud before clean out since clean out is more like suck out) after the 2" trap reduce it on the way back up to meet the 1-1/2" pipe.
What a mess and why did anyone install such skinny drain pipe??? Any suggestions on a remedy for this mess, other than giving up on the Mastershower?
Pictures of the situation:
1-1/2" pvc to steel ell
pvc into threaded coupling into ell
View down the drain to coupling
Any advice would greatly be appreciated , thanks in advance!