I live in a NYC highrise and I'm trying to put in a new shower (part of a master bathroom) where a kitchen previosly existed . I want to run a pitched 2 1/2 inch pipe from the new shower pan (without a p-trap) about 4 feet, through a wall, to another bathroom where there is an existing vented shower drain which has a p-trap. The 2 1/2 inch pipe would be connected to that existing drain. This second shower will not be used except to serve as the drain and p-trap for the new shower in the former kitchen. While the kitchen does have an adequate drain pipe, I am advised that using the available kitchen plumbing will result in a new shower floor 10 to 12 inches above the ground. I am trying to avoid this by using the drain in the second shower described. Can this be done and will it meet NYC code? Many thanks.

speedball1

I guess it would work although I'm not too sure it would pass code. Since you're going to have to get under shower #2 to connect shower #1 to the traps raiser and use that trap to secvice shower #1 why not do the job right and trap shower #1 and connect to the drain line of shower #2 using a wye or a 2" combination wye and 1/8th bend? That way you would be wet vented by shower #2 and stay within code. good luck, Tom

jernew

Thanks for your response Tom. Assuming it's your way, would the trap in shower #2 have to be terminated or removed, or can it be used in addition to new trap in shower #1. It may be difficult to terminate or remove trap #2 as it is likely to be deep in the cement between floors. Is the "wet vent" in shower #2 sufficient if Shower #1 is 4 feet away and not otherwise vented? Should a vent be added to shower #1 inany case? What if the bends in the pipes make it 5 feet away?

speedball1

What I'm suggesting is that you connect shower #1,( the proposed shower) downstream from shower #2's trap in the drain line using a wye or a 2" combination wye and 1/8th bend. This will not necessitate removing the trap from #2 as the two will still remain workable showers, but now you tell me #2's trap and drain line's buried under cement and how many bends are we talking about? If you connect either way #1 will still be wet vented by #2.
If the trap from #2 is buried in cement how did you plan to connect to it?
Waiting on your reply, Tom

jernew

I'm not planning on using shower #2 as a working shower, but rather only want to use the existing drain and/or trap so that we don't have to raise shower #1 by 10 to 12 inches. Can shower #1 run downstream to shower #2's drain in this case? I don't know how deep the trap is in the cement, and therefore don't know how to connect it or how to terminate it. The shower floor will have to be opened to determine this. Can it be left there? The drain will likely be accessable. There will likely be 1 or 2 bends. Your help is appreciated.

PalmMP3

Sounds like what you want to do is a process called "indirect waste" - whereby one fixture, rather than being trapped and connected directly to the DWV system, will instead simply drain through an "air gap" into another fixture (examples include a floor drain, or - in your case - another shower pan), and the second fixture handles the draining of the waste as if the waste had been dumped into the second fixture to begin with. (Even if that's not exactly what you had in mind, it's definitely a good idea - read:easiest option - if it could be made to work, and if it is permitted.)

On the NYS Department of buildings website, there is a page listing the building codes of NYC. I looked through the document titled "Plumbing, Drainage and Gas Piping" and found quite a few references to indirect waste - in fact, in some situations it is actually recommended/required. However I do not understand the legalese-style terminology well enough to come to a clear conclusion about whether what you want to do will be permitted or not - if you want to try reading it yourself, knock yourself out.

Here's a direct link to the PDF. Enjoy!

Good luck,
Moishe

speedball1

Moshie caught it before I did. I thought you wanted to connect to shower #2's trap raiser so you could leave shower #1 on the floor. what you're proposing is to raise the floor of shower #1 up enough to place a elbo on the drain and dump it into the drain of shower #2. This is indeed a indirect waste and a bad idea. Over time rotting hair and grease would start to smell in the untrapped drain line, especially if you have elbos in the line.
It's a "Mickey Mouse" set up from the gitgo and one that NYC would frown on. Now if you wanted to take out shower #2's shower floor and connect to the existing trap raiser, As I thought you did at first then I would say OK.
Also I would like to hear how high you would have to platform the shower floor of shower#1 to accommodate a drain, elbo and drain line. What you are proposing is bad plumbing. There just isn't any other way to describe it. Besides, having two side by side showers with one inoperable doesn't make much sense to me . why do you want to replace shower #2 with #1? I hate to rain on your parade but that's the way I see it. Regards, Tom