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Author:
Palm329 (VA)
Just trying to lay out my new secondary stack venting properly in the basement, it picks up a kitchen upstairs, then in basement there was a utility sink with washer draining into it, then below floor it picks up the floor drain. These are vented by a parallel vent line which forks off the main vertical upstairs in the 1st floor wall. I could post a pic but you've probably seen this design a thousand times pretty basic.
Anyway I'd like to plumb in the basement sink drain in one direction and the washer in the other and I've come up with 3 ways I think are valid to do this. lookkng for confirmation of the following theories, or shoot it down and tell me why it's a trash idea:
1. I can use a double Sani-t, one side to the sink, the other towards the washer. Advantage of this is both trap arms may be vented off one vent; disadvantage is that sometimes water can fire across the sani-t one side to the other. Additional advantage the whole assembly can fit inside drywalled 2x4 wall (2" pipe)
2. I can use double wye with 45 deg streets in the same way. Advantage better water flow directed down, disadvantage I think I need two seperate vents on each trap arm? Additional disadvantage more width and can't fit inside wall cavity.
3. (Leaning towards this) I can use a wye with 45 street to split drain to create two parallel vertical pipes. Then I can install regular Sani-t in each headed towards each trap arm. Two parallel vents would continue up out the top of each sani-t then join up with vent stack 36" above trap arms.
3rd option seems best but I'll end up with loads of pipe inside wall and I guess I'll just have to frame around it and hope nobody leans up on the drywall haha
Any thoughts on this? Thanks so much!
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Author:
holland123 (MI)
The double tee (option 1) would be just fine and is code where I'm from, I would however not reduce the common vent on that one unless you are going to be using a high efficiency washer. Any time I run into venting problems it is almost always with laundries and older top load washers.
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Author:
sum (FL)
There is a fitting that is specifically designed for performing like a double sanitary tee and yet minimizes the chance of the snake bouncing across. It's called a "double fixture fitting" or "double fixture tee". I don't think it eliminates completely the chance of a snake cross over but it's designed to minimize it.
I looked for one two years ago and both plumbing supply stores nearby don't have it. In fact when I explained what it is they told me to use a double san tee.
Edited 1 times.
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Author:
hj (AZ)
In that case neither one is a very good supply house.
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Author:
hj (AZ)
The double tee/cross is NOT an option in this area, nor in any one where I have ever been. The back to back fixture fitting eliminates the problems with a cross or a double y.
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Author:
Palm329 (VA)
Okay this is great info so just to confirm I'm understanding exactly what you guys are referring to, if I used something like the "Spears P500" fitting: [ecx.images-amazon.com] that is the kind of fitting you are referring to?
With this part flow will be directed down properly but I do not need to vent each branch because the single shared vent coming off the top will be high enough above the waterline?
I've never seen this part at home despot or low's so I might have to order it online if this is what I need.
Thanks!!!
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Author:
steve (CA)
That's the correct type to use.
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Author:
sum (FL)
they may not be, but they are the "biggest" in town so I don't have much choice. The surprising thing is they didn't know what I was talking about, and when I explained to them they said "oh you mean a double san tee or san cross!" I said no no no...it's different, and they looked at me like I was from Mars.
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Author:
North Carolina Plumber (NC)
Why not just stack 2 sanitary tee's ? Seems to me that if you use a back to back fixture fitting either the sink drain will be too low or the washer too high.
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Author:
Palm329 (VA)
Can I wet vent the washer drain like that? I forgot about that option
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Author:
North Carolina Plumber (NC)
Yes.
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Author:
Palm329 (VA)
Thanks I got it together last night.
Stacked sani-ts will connect where the capped off pipe in the center is located. Top sani-t will tie into revent pipe on right. Floor drain vent probably not 100% code compliant but it's the best I could figure out that would fit in the space. (These pipes all need to disappear into a wall...
Thanks!
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Author:
hj (AZ)
Given the quality of plumbers you encounter, I guess it is not surprising the wholesalers are no better. No reason to stock a fitting that none of the plumbers know how to use.
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Author:
hj (AZ)
As long as the sink is on top.
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Author:
hj (AZ)
I cannot think of any condition where that upside down "Y" would be code compliant.
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Author:
Palm329 (VA)
Just to clarify that upside down wye is a totally dry vent line. No drains connect above it, heads up to the roof.
Many previous threads on this site have claimed that in a vent line the fittings should be angled as if the air is flowing thru them...
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Author:
hj (AZ)
yes, that "Y" is too LOW to be legal, at least from the angle of your picture.
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