Washing machine discharge, standpipe under the IPC, tapping main sewage trap
 

My neighbor has a sewage line that runs under his concrete floor for about twenty feet before exiting the house. Right before the line exits the house there is a trap, also under concrete. He would like to drain his washing machine through the trap. I said make sure you drain before the trap. Here is the picture I drew:
http://img16.imageshack.us/img16/8900/clipboardyu.jpg


The question (assuming it is a legitimate one) is how to drain through the trap. Here is what I would probably consider most common. What he could do is buy one of those cast iron donuts and fit a piece of pvc pipe in it about 4 ft tall, and then just stick the hose in it. Here is the picture I drew for you guys:

http://img403.imageshack.us/img403/807/clipboard2g.jpg


The second way would be to have another trap and I assume an AAV? I'm not a plumber, I assume that's pretty obvious.

http://img259.imageshack.us/img259/2631/clipboard3o.jpg


Also I wonder if however it is done the washing machine drainage hose can just be stuck in the pipe or whether or not there should be some sealed connection, like some adapter pvc slide to washing machine line or something. Tearing up the floor is not an option here. The next closest connection is 20 ft away horizontal and 5 ft away vertical before I can see pipe coming out of the concrete. The house is probably early 1900s. Thanks

After some research I've found my county (Westchester) is under the IPC for plumbing. I've found a lot of standpipe questions from DIYers but most are concerning the IRC. Here's a great picture from a NACHI forum post:
http://www.nachi.org/forum/attachmen...-standpipe.jpg

From what I can gather the pipe must be 2" in diameter. I am not sure about the distance. I read a Home Repair forum post that also addresses the IRC and says the distance from the trap to the vent must be 4" at least. Here's the picture:
http://www.homerepairforum.com/image...h_AAV_w550.JPG
What's the maximum and is that the same under the IPC?

Would anyone care to quote the IPC or address what my neighbor plans on doing? It just doesn't seem right but I don't think that's going to stop him. My main concern is that sewer gas doesn't kill him that's why I suggested he tap in on the house side of the main sewage trap.

Also: if someone could explain what exactly a weir is and where exactly it starts. I read somewhere that measurements for standpipe apply from the weir up. I have no idea what that means. if you look in that first picture they basically are measuring from the center of the horizontal pipe, not from the weir (which from what I can gather is some type of dam or in this case maybe the bump in the trap?)

The washing machine hose must fit loosely into the standpipe or drain pipe and must not be spliced to reach further.

Thanks Allan I will make sure to look into that. What do you think about putting the line over the trap like as I show in the first pic? I assume the IPC has something to say about that. For example I know that sanitary tees cannot be used on the horizontal connections at some points and I read that wyes are needed because the water velocity is supposed to go one way. I recognize the setup might not be up to code but my main concern here is one of safety. This is an old house and he doesn't have the money right now to dig up the floor.

http://www.sweethaven02.com/BldgConst/en5112a0074.gif

P.S. : If you're using a 2" x 1-1/2" x 2" Sanitary tee and a 2" p-trap there is no way the distance from the weir to the vent can be less than 4" , unless maybe you put the street end of the p-trap 90 into the sanitary tee. Even then, it would be close.

On the first picture if that’s the way it would be piped in is no good. That’s considered a running trap . in front of mechanical discharge it would pull the trap dry.

If you are going to use weir equations you would need to bump that branch up to 3” up to the receiving sanitary tee. weir equation or fixture units. Under the ipc you cannot go into the sanitary tee with a street 90 off the trap .that would considered an s trap min 4” max 48”

I'm a little lost. What do you mean by mechanical discharge? Check this out:
https://www.ridgidforum.com/forum/at...lumbing-64.jpg

Except the vent would have a sanitary tee and take water (so it's a wet vent?).

Are you saying that, for example, in the NACHI pic that the tee would have to be coming from the top 2", coming from the side 2" and coming from the bottom 3" dia?


I also read a thread about a running trap and the ipc where a plumber from New York says this about the IPC: