Combining pipes in Basement plumbing

[darren_t_johnson]

Hi,
I’m adding new bathroom in my basement and I’m moving a lot of the existing plumbing around to make room. All of the plumbing for the new bathroom is not relevant to this post (for now). It will tie into the main pipe further downstream, and I’ll be putting a new vent through the roof to service all of the fixtures (toilet+sink+shower+tub).

I’ve had a plumber come by twice now, and we talked over all the details. And I have my building permits, so everything will be inspected at the proper stages.

However, there is one area we talked about and I either forgot some of the details, or we did not discuss it specifically. We focused more on the new stuff then then old. So please look at pic1 and pic2. They show the existing plumbing. Pic1 also has more details written on the drawing. The two vertical stacks take up a lot of room, especially because I would need to keep the clean outs accessible. To avoid this, I’ll be moving them to the left (where the concrete floor has been broken up.



Pic3 is a hand drawing of how all of this will look. I will cut the cast iron stack near the ceiling, use fernco coupler to transition to ABS, use a 90 and run the 3” ABS along the wall, then a 90 to run the 3” ABS down to the floor.



The 1.25” vent shown in pic1 is not enough to service a laundry sink and washer, so I will be venting the laundry tub and washer drain as shown in pic3, and I’ll tie that vent into the new 3” vent I’m adding. I’ll tie it in above the flood line of all the fixtures it services.

Before I continue, are there any other issues with pic3?
The San-T that I circled in red… I’m pretty sure this needs to be a wye (with a 45, or long sweep). Is that right? I think I want to use a 2x2x1.5 wye that comes off with a 45.
Is the 1.5” vent is large enough for the laundry tub and washer? From my understanding it is.
I know there is a maximum “length of trap arm to vent”, which I will satisfy. But is there a minimum distance a vent needs to be from the trap?
The 4x4x3 Tee-wye at the bottom, I’m using the 3” off the side because that 45 will go into the wall, so that all the plumbing above it will be in the wall, not out in the space.

My other Question is with the two pipes (1.5” drain and 1.25” vent) that come down from the kitchen. Right now they run directly into the floor. The 1.25” vent is no longer needed because the laundry is tied into the main stack, so I’ll tie the two together as shown at the top of pic4. And I’m already tying the laundry into the main stack. Is there any reason I can’t do the same for the kitchen?
Pic4 shows three examples of how I could do this. Is there any reason I can’t? I don’t remember the plumber saying I could or could not. Is one of my examples better than the other?
I like option #1 the most. Option 3 will consume more head space.



Thanks in advance!

[darren_t_johnson]

No responses?
I guess all the plumbers are taking Friday off?
Did I throw too much information into one post?

[Terry]

I would give it a day or two. Friday might have been busy. It was for us.

[darren_t_johnson]

no worries. I was just joking around. Everyone has their own jobs and life... and it was friday. I think its great that people take the time to help answer questions on forums like this.

[darren_t_johnson]

Hi, does anyone want to take a stab at this?
Despite all the information, I really only have three questions.
1) In pic3, the circled San-T should be a WYE or a long sweep combo right? San-T's really should not be used to transition like that.
2) In pic4, option #1 is ok right? It is the same type of join I see in laundry setups all the time.
3) Is there a minimum distance a vent must be from a trap?

Thanks!

[mikeplummer]

Hi, does anyone want to take a stab at this?
Despite all the information, I really only have three questions.
1) In pic3, the circled San-T should be a WYE or a long sweep combo right? San-T's really should not be used to transition like that.
2) In pic4, option #1 is ok right? It is the same type of join I see in laundry setups all the time.
3) Is there a minimum distance a vent must be from a trap?

Thanks!

1 - you are correct in taht you cannot use a TY on its back, that has to be a wye and 45

2 - if the 1-1/4" vent isnt serving any fixture it is ok to connect it there......

3 - there is a minimum distance between trap and vent - 2 times the diameter of the drain is minimum trap arm length

[darren_t_johnson]

Thanks Mike.
Now I need to dig out the rest of the drainage gravel and buy a lot of ABS!