Please help with my sanitary drainage and venting plan

[Nick Bosco]

Please critique (help) my drainage and venting plan.

I am adding a bathroom to the second floor of my home and I would like to keep all of the plumbing within the floor joists.

None of the new bathroom's walls extend to the first floor, so the only opportunity to run the waste stack down to the basement in through a first floor wall which is located in the middle of the floor of this new bathroom.

Thanks in advance.

Nick

 

[Reach4]

WC will probably not need its own vent.

 

[Sponsor]

 

[Terry]

The shower vent needs to be vertical.
The only horizontal vent you can get away with is one that can be snaked (washed)
Often we will run the lav in 2" which can act as a vent for the toilet and shower depending on how the lines come together. That being the case, the lav could have vented the shower.

 

[Nick Bosco]

Thanks for such prompt responses. I've updated my plan removing the shower vent and adding some approximate distances and pipe dimensions. Would it also be possible to remove the WC vent?

 

[Terry]

The toilet can't run by the shower that way.
Pull the lav off the 3" for the toilet like you have it, and then the shower (2") comes off the 2" lav, not the toilet line.
The toilet won't need it's own vent.

 

[Reach4]

I've updated my plan removing the shower vent

You need the shower vent. It is the toilet vent that you may not need. Since the shower vent is horizontal partly, maybe you do need the toilet vent too. Terry is describing a rearrangement where you only need the lavatory vent, but you have to rearrange the drain lines.

 

[Nick Bosco]

Unbelievable the help here!!!

This?

 

[Terry]

Okay, I like this one.

 

[Nick Bosco]

Awesome! Thanks so much.

 

[Nick Bosco]

One follow up. Could I get away with a 1.5" line for the shower branch?

 

[Terry]

The shower is always 2" in Colorado.