Help designing my bathroom greywater line

[cst1988]

I have a blank slate, it's

only one floor with a crawl space under. I am about to purchase parts to plumb drain lines and want to make sure I get the correct materials. There will be a separate garden tub, shower and sink only on this line, it also needs to include vents. Shower will have 2" P trap, bath will have 1 1/2" P trap. Could someone draw in or explain a simple design for me?

 

[cst1988]

I have a blank slate, it's View attachment 106068only one floor with a crawl space under. I am about to purchase parts to plumb drain lines and want to make sure I get the correct materials. There will be a separate garden tub, shower and sink only on this line, it also needs to include vents. Shower will have 2" P trap, bath will have 1 1/2" P trap. Could someone draw in or explain a simple design for me?

 

[Sponsor]

 

[cst1988]

A buddy of mine sketched this out using 2" lines throughout, the vent (green lines) connects to the waste on top and slope in the same fashion as the waste lines. Does this configuration meet code?

 

[Reach4]

Lines are confusing.

Is there a toilet? Where does the drain line leave the bathroom area?

You can probably just have a dry vent to the lavatory (bathroom sink), and wet vent the other two things under the floor.

 

[cst1988]

Lines are confusing.

Is there a toilet? Where does the drain line leave the bathroom area?

You can probably just have a dry vent to the lavatory (bathroom sink), and wet vent the other two things under the floor.

 

[cst1988]

So the toilet is going on the existing septic system, separate from this system. This is just for a garden tub, walk in shower and sink, they are draining out the exterior wall between the shower and tub.

 

[Reach4]

1. I drew that without regard that this is not going to the septic.
2. Connect a wye from the tub an another wye from the shower. Place those to let the paths from the traps to be good. Do not use a double wye.
3. While I think 2 inch is sufficient, I am not sure that it should not switch to 3 inch when the both the tub and shower join. I am not a plumber.
4. On page 12 bottom of https://wabo.memberclicks.net/assets/pdfs/Plumbing_Venting_Brochure_2018.pdf there is a big wet vent example. For connecting two traps for the two lavatories you could use the method shown there. That shows a double fixture fitting. But there are other ways.
5. The dry vent could be a real vent or an AAV. The vent line above the double fixture fitting can be 1.5 or 2 inch.
6. The transition from the vertical exit of the double fixture fitting can be a long sweep. Only uses 45s, wyes, or 22.5s, plus the swing on the traps to change directions. You can also use a combo (=wye+45), but I don't see a need for that.

 

[cst1988]

View attachment 106176

1. I drew that without regard that this is not going to the septic.
2. Connect a wye from the tub an another wye from the shower. Place those to let the paths from the traps to be good. Do not use a double wye.
3. While I think 2 inch is sufficient, I am not sure that it should not switch to 3 inch when the both the tub and shower join. I am not a plumber.
4. On page 12 bottom of https://wabo.memberclicks.net/assets/pdfs/Plumbing_Venting_Brochure_2018.pdf there is a big wet vent example. For connecting two traps for the two lavatories you could use the method shown there. That shows a double fixture fitting. But there are other ways.
5. The dry vent could be a real vent or an AAV. The vent line above the double fixture fitting can be 1.5 or 2 inch.
6. The transition from the vertical exit of the double fixture fitting can be a long sweep. Only uses 45s, wyes, or 22.5s, plus the swing on the traps to change directions. You can also use a combo (=wye+45), but I don't see a need for that.

See this is how I first drew it out. My concern was the distance from the wet vent to the p trap on the tub and or shower. To my understanding for 2" you only have a maximum of 8' from the bottom of the sink transition to either p-trap. Although up sizing the main run to the 3" may be the solution there.

 

[Reach4]

Wet vents are magic in that while the distance from the trap to the vent is limited, the distance for a horizontal wet vent to run is not-- as far as I know.