Venting help please?

[PeterPiper]

Greetings! New construction, one bathroom on the ground floor with a shower, toilet, and sink, then a kitchen sink, dishwasher, and washer on the opposite wall. Can someone help or advise me on my main stack size? Can all drain vents be 1.5"? Thanks.

 

[GReynolds929]

Unless there's a bathroom upstairs you won't have a stack. Size is based on the fixtures draining into the pipe. Toilets require 3", most residential main building drains are 3". Toilets require 2" minimum vent, most everything else requires 1 1/2" minimum. You can't reduce the size of a drain. What is the 2" line going from the toilet to the shower.

 

[PeterPiper]

Unless there's a bathroom upstairs you won't have a stack. Size is based on the fixtures draining into the pipe. Toilets require 3", most residential main building drains are 3". Toilets require 2" minimum vent, most everything else requires 1 1/2" minimum. You can't reduce the size of a drain. What is the 2" line going from the toilet to the shower.

Thanks! I'm assuming that 2" line in the slab running from the toilet to the shower is the vent for the toilet, or meant as venting for the whole system?

 

[GReynolds929]

Can't be a vent if its in the slab. Not legally anyway. Is it not the shower drain? Drain from upstairs? Who did the ground work? If the washer trap arm is greater than 60" it needs a vent.

 

[PeterPiper]

I decided to have the plumber who did the slab work to do the venting and the rough in for the fixtures. I can do the rest.