Plumbing question - will this work?

[caw1982]

I am working on roughing in the plumbing for a master bathroom and have a question about running my 3-inch PVC. I cannot run directly to my main stack because I have ductwork in the way. My only other option is to run around my basement which leaves me with a straight 20 foot run, then a 90 degree angle, followed by another 20 foot run and another 90 degree angle into my main stack. I can obtain more than ¼” per foot of slope throughout the entire run. I will be able to tie in a vent about three feet from the start of my run. Any advice or information on the possibility of this working would be great! Thanks!

[geniescience]

that's a fascinating question.

As long as you have that vent like you say you do, and you have that slope like you say you do, you may very well be fine.

Post a diagram just in case there is something else that is not yet expressed that needs to be checked. Is this a 3" toilet run? What size vent ? Etc.

david

[markts30]

...Don't forget the cleanouts you are going to need...
Drains not to exceed 135 deg. without a cleanout....

[caw1982]

3" pipe with 1.5" vent.

I was going to put a cleanout at every corner. Would I be better off with two 45 degree turns instead of a 90 degree?

[The old college try]

I agree. 90 degree bends will plug easily as they slow down flow through the pipe.