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constructing new drain stack - need some pointers

849 Views 3 Replies 2 Participants Last post by  TheEplumber
Hi everyone,
I'm replacing old cast iron drain stack with sch 40 PVC.
I have attached a diagram of proposed setup (not to scale). Also Pic of basement setup before removal of CI pipe.

A few things I need to clarify:

1) for horizontal runs into main vertical stack I will use sanitary tees (LABELED A) NOT WYEs (plus a 1/8 bend).

2) If the above is correct will the horizontal 3" pipe attached to the 90 degree closet bend fit well into the san-tee, which has a slight upward tilt?

3) The 2" pipe from 2nd fl shower may be at a greater gradient than 1/4" per foot to accommodate for the toilet connection. Is this OK?

4) I will use a wye (LABELED B) NOT a san-tee for the 1st Fl bathroom run into the basement horizontal.

5) I will use a rodding tee for a cleanout next to sewer. Should I also put an angled wye with screw cap pointing down by sewer to make access if needed easier? The original CI cleanout is rusted shut.

6) does the 45 degree elbow (LABELED C) need to be wide sweep?



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Santees in the vertical are fine- no need for wyes in this case, but the 4x2 shower tee could be a wye set lower in the stack, with a vertical 45- then use a 90 on top of the 45 to make the 1/4" grade...

For the toilet- the PVC will have enough play when glued- so getting the grade won't be an issue- add support to any horizontal lines.

The clean out tee at the base is fine.

Not sure where "C" is- if it's the toilet, a 90 is what you want
Thanks for the reply.
C was the 90 degree elbow in basement for 1st floor toilet. I will put a long sweep elbow there. Should I also put a clean out a the end of this horizontal?

No need for a clean out on the branch

A couple of questions about venting. ...
The 2nd floor shower/sink pipe has a vent before the vertical stack.
I didn't include in diagram as I just located it.

You need to vent the shower

The kitchen sink was direct vented into main soil stack. I think this is against code.

Depends- are there fixtures above it? I can't find it on your drawing.

Not sure about venting of 1st floor bathroom fixtures. I'll check them.

They need vents

On the iron pipe setup there was a vent (iron pipe - the pvc pipe is from basement sink i removed) going in at the basement just above the floor. Pic attached. This vents to roof. I could reconfigure this to vent the kitchen sink and possibly the 1st floor bathroom fixtures.
You can tie vents together, they need to be 6" above the rim of the fixtures served when connecting. They also need to be sized properly
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