Bathroom plumbing questions in 1960s house

[Trey]

I am in the process of remodeling a bathroom in my house that was built in the 60s. I've drawn up (forgive my poor writing!) A quick sketch of what I'm putting in and wanted to see if anything looks off.

-does the venting look sufficient? There are only three sinks that utilize that vertical pipe for draining from above. I am adding a bath/shower combo that pipes in at the combo wye that will utilize the same drain/vent as the toilet and three sinks. Not sure if I need to add a separate vent from the shower drain to connect to the vent pipe further up in the wall.

Any input is helpful, thanks!

Trey

 

[Trey]

Also, any thoughts on connecting PVC to the old cast iron drain pipe under my foundation? I'm connecting to a CI 3" coupler so I was planning to use a fernco donut but not sure if I should use any kind of compound to help seal the joint. I really don't want to have to dig it up again in the future

 

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[Terry]

You can't wet vent from a floor above. Wet venting takes place on the same floor and they are bathroom fixtures.
Not kitchen sink or laundry sinks.

 

[Reach4]

Toilet above should feed into a 45 which feeds into a wye, or a combo, which is a combination of a 45 and a wye.

 

[Trey]

That's what I was afraid of.. that's how the original plumbing was set up, I was just tying in a new shower/tub.

 

[IPDQKWID]

Toilet above should feed into a 45 which feeds into a wye, or a combo, which is a combination of a 45 and a wye.

Trying to find answers to a few questions, and upstairs toilet is one of them. Do you mean that a pipe attached to the closet flange should at no point turn horizontal on its way to the stack? Or are you saying that at the stack it should not an elbow? I hope that made sense. Thank you.

 

[Reach4]

Do you mean that a pipe attached to the closet flange should at no point turn horizontal on its way to the stack? Or are you saying that at the stack it should not an elbow?

Neither. When waste from something else joins the toilet stream it should come in at 45 degrees or through a combo.

There is more than one right way to do things. If you join the flow with a lavatory on the same floor, that makes venting much easier.

So if you describe where stuff will be, and which way the sewer line leaves the area, somebody will probably tell you a good way to route things.

In your drawing if you have your vented lav drain join the shower drain, and the combination then merges with the toilet at 45 degrees, you are probably good. If the lavatory and shower and toilet are on the same floor, your sketch is close.