Adding Standpipe to Soil Stack

[sdz]

Hello
Just wondering if it would be okay to add a sanitary tee into existing soil stack in the basement which has a toilet and bathtub on the stack on the main level, its vented on the main level. I'm looking at adding a softener in the comer of the room. The stack is 4" I would add the 4"x 4" x 1-1/2" into the stack about 3' off the ground. The softener is going to be located about 5' away from the stack id run 1-1/2" abs with a p-trap at the end of the run and tie that into a 30" standpipe will this work?

 

[Reach4]

It would work, but your standpipe is required to have a vent to the trap arm to meet codes. An AAV could be used for that. If you think you might want to use that standpipe for a washing machine some day, make that 2 inch.

https://terrylove.com/forums/index.php?threads/standpipe-and-aav.43627/

 

[Sponsor]

 

[sdz]

Perfect I will up the size to 2" and add a combo wye just before the p-trap and add in the pipe / AAV also just got a question on the sanitary tee off the soil stack if I want to bring the new drain close into the wall should I go with a long turn 90 elbow off the tee then a short off the wall or does it matter? Also judging by the picture do you think there will be enough play to just add the tee into the stack or will I be using fernco couplings?

 

[Reach4]

You will need 2 banded couplings, and two short sections of pipe.

got a question on the sanitary tee off the soil stack if I want to bring the new drain close into the wall should I go with a long turn 90 elbow off the tee then a short off the wall or does it matter?

I think you are asking what fitting would be best to insert into the 4-inch pipe. You don't need a combo for that, but you could do that. HJ blessed a santee for that, so that sounds good. With a santee, if your AAV failed closed, you would never know it. I expect that it it is highly probable that the 4 inch stack would serve as a great wet vent for this, even though it is not permitted by codes. I am not a plumber.

 

[sdz]

This would be the 2" coming off the 4"x 4" x 2" tee the main stack is about a foot away from the wall just wanted turn the drain into the wall and was wondering if it had to be a long 90 off the 2" tee then just a short 90 to go back along the wall. If that makes sense.

 

[Reach4]

This would be the 2" coming off the 4"x 4" x 2" tee the main stack is about a foot away from the wall just wanted turn the drain into the wall and was wondering if it had to be a long 90 off the 2" tee then just a short 90 to go back along the wall. If that makes sense.

I think horizontal to horizontal can be a short sweep. However how about a 45?

Red represents using a 90 bend, and green tries to represent a 45.