Help needed drain tiny bathroom

[Ponti]

Hello everyone,

I’m currently in the process of transforming a closet into a small bathroom (approximately 36”x6’) and could really use some expert advice on the drain layout. I’ve attached a layout picture for reference, but I’m unsure if the proposed configuration makes sense.

Specifically, I’m puzzled about whether I should opt for long elbows or if regular elbows would suffice. I’m facing two challenges: one involves navigating around a metal beam, and the other requires a transition from horizontal to vertical in the basement due to another obstructing pipe. The latter means the drain has to drop about a foot before continuing towards the 4” main stack.

I’m open to any advice or insights you might have regarding the drain layout. Additionally, I’d appreciate guidance on venting. At the moment, using an AAV and a wet drain seems like the only feasible option as the vent stack is quite a distance away.

For context, the materials I plan to use are cast iron for the 3” toilet drain and copper for the 2” and 1.5” drains for the shower and sink, respectively.

Thank you in advance for any help or suggestions you can provide!

 

[Jeff H Young]

36 inches gives you how much room in front of lav ?
your iso shows san tee backwards with AAV for vent .

 

[Sponsor]

 

[Ponti]

36 inches gives you how much room in front of lav ?
your iso shows san tee backwards with AAV for vent .

Hi Jeff, in front of lavatory is 24”, the lavatory is about 12x12”. You’re right the orientation of the san tee is wrong. Do you think that aav and wet vent part is enough to properly vent the fixtures? Thanks

 

[Jeff H Young]

it should be good dont know wht you dont just roll up a combi for the lav instead of all those 90s but looks ok to me

 

[Ponti]

There is a big joist there going along the wall, it is 120 years old so I prefer not to touch it. That’s why I go to the end wall, then go up and turn to get to the lavatory. Thanks.

 

[Jeff H Young]

I guess no cabinet under the small sink and an exposed pipe is undesireable so Im with you there!