Draining 2tubs 1 shower into 1.5

I want 2tubs and 1 shower in total. 1 tub in guest bath. and 1tub 1 shower in en-suite.

I'm remodeling my apartment condo and it has two bathrooms that back up onto each other. The condo is very specific that everything must be done to code. the wet wall inbetween the two bathrooms has a 4'' stack off comes a 1.5 which two tubs currently drain into. Part of that 4'' T is buried in the concrete and is Cast iron. The 1.5 fitting off the cast is threaded and looks like it's almost 2inches but i've conflicting reports one plumber says it's a 2inch other says it's a 1.5threaded(master plumber). Anyways there's also a 3'' toilet pipe that runs into the same 4" stack.

What i'm wondering is. can i put the tub on a platform high enough to allow for proper slope and drain into that 3'' pipe that the backflush toilet backs onto?

or is there some other solution?

pipe

we can't tell you because you do not give us any information on where the tubs are to be placed, or how they might connect to the piping. A 1 1/2" pipe is almost too small for two tubs and definitely too small for a shower, even without the other two tubs if they are all going to connect together. What kind of plumbers are you talking to if they cannot tell what size pipe it is?

Yes, a raised tub can drain into the 3". Still, conditions apply. E.g. Venting. And others.

2.. Tell us if it is to be a tub-shower or a tub and separate shower in the ensuite.

3. Measure the Outside Diameter O.D. of the pipe you are looking at and tell us what that dimension is, and whether the material is Cast Iron or Copper at the place you measured. This will be sufficient data for someone to then tell you what the Inside Diameter I.D. is at that point.

shylok, i don't like this username.


david

A stand-alone shower by itself requires a 2" drain line back to something bigger. A tub/shower combo can live with 1.5".

Tubs are back to back. and they currently drain into a 1.5 x1.5x1.5 Y (wye) and that is copper which goes into a 4in cast iron stack. The T in that cast iron stack LOOKed to be 2inch but according to the master plumber it is a 1.5inch threaded.

I will measure it and post back my measurement tm.


I'm trying to have the two bathtubs, and add a single stand up shower at the other end of the bathtub.


i've included the bare naked pics of the plumbing for you to take a look at along with the bathroom proposal/plan. thanks for all your help!

pipes

Using the vent as a gauge, it appears that the bottom arm is larger so that would make it 2", but the picture is not clear enough to be sure about it. What kind of tee is the pipe connected to? I have never seen one with 3" on one side and a 2" opening lower on the opposite side and no sweep, although it could be some specialized fitting for apartments like that.

Here is a thought - not sure if you can do it....
Can you (is there a way to?) tie into the old floor mount toilet closet flange?
https://terrylove.com/forums/attachment.php?attachmentid=1274&d=1159480252
In this pic it looks like an old floor mount WC had been located below the one tub - you could, if able, drain the shower into there and tie the vent into the others....
Just a thought...
Interesting dilemna...

ah if you mean that toilet ring on the ground?? thats just sitting there.. it's not actually a pipe underneath. it goes onto the backflush 3" waste pipe. just happend to get knocked off when toilet was pulled off. lol. i didn't realize it looks like a pipe.

hj said:

Using the vent as a gauge, it appears that the bottom arm is larger so that would make it 2", but the picture is not clear enough to be sure about it. What kind of tee is the pipe connected to? I have never seen one with 3" on one side and a 2" opening lower on the opposite side and no sweep, although it could be some specialized fitting for apartments like that.

Click to expand...

the 4" stack has a fitting in it thats got a 3" on one side that the backflush toilet backs onto. and the other fitting on the other side is a 1.5'' threaded fitting. it's got copper in it currently as you can see that splits into a Y for both tubs.

Makes sense - the fit is a 1.5" since I see no reducing coupling (from 2" down to 1.5") after it along the way to your 1.5" copper tub connection. I think most people reading this thread were waiting for you to confirm it yourself before commenting. It was still remotely possible that the stack connection we saw in the picture came in at 2" after all, and that 2"-to-1.5" reducing happened at a previous corner (fit). Your metal stud channels look small by the way. That is good. Saves space. Are they 2"? i.e. 2.5".

Seems to me 90% probable that a Master Plumber will have to put a 2" onto your stack. More work than otherwise. Needs a licence and liablity insurance. Not going to scare away a serious plumber though. Unlicensed guys will run from this. My take. My experience. Where you live things are no doubt different.

Remember that tub-showers only require a 1.5", by code, everywhere in North America.

I hired a MAster Plumber to re-do ALL my drain plumbing, I am in a condo building with concrete slabs and 4" and 6" stacks. Two years ago I had similar planning work to do as what you are now doing. I learned a lot, and found many ways to "skin the cat". Here is the funny part : my Master Plumber installed a 1.5" drain and P-trap for a stand-alone shower, knowing that Code required 2" and remembering fully that my first spoken words were to ask for a 2" pipe for a shower. He said 1.) I didn't have the space, in your downstairs neighbor's ceiling cavity, and 2.) I warrantee the job and I am fully insured, and 3.) over the 18" distance there won't be a significant loss of flow versus a 2" diameter pipe, since "distance" or length is the reason and the only reason why Code now requires 2" while it never did before in our father's days. Furthermore I had installed a lot more new venting everywhere, much more than minimum Code (in my part of the country, for multistory concrete buildings).

I thought you might like to know.

david