New shower drain meets 3" drain and distance from existing vent

[Scott45]

I'm adding a 2" shower drain to an existing 3" drain and I've the following questions:

1) There's a 3" vertical vent 6' upstream from where I plan on connecting a shower only (no tub) drain to the 3" drain. Is the vent location going to be an issue?

2) The shower drain is in the same floor joist cavity as the 3" drain it needs to connect to and mercifully it's offset enough for the p-trap to sit comfortably next to the 3" drain. The trap exit can be up to several inches above the 3" drain if needed but not sure if there's a rule of thumb there.

What I plan on doing is inserting a 3"x3"x2" wye about 2' downstream from the p-trap and using an assortment of 22.5 degree elbows to get the waste water into the 3" drain from the trap exit. Is there a minimum or maximum distance between the p-trap exit and where the downward connectors funnel the water into the 3" drain? I feel like if that distance is too short I'll get close to an S trap situation.

Thanks!

 

[hj]

IF you are in an "S" trap situation, it does NOT MATTER how close, or far, it is. Is that a "vent" or the drain from an upstairs bathroom?

 

[Sponsor]

 

[Jadnashua]

The length of the trap arm depends somewhat on which code cycle your location uses. With a 2" shower drain, in many code situations, the vent must occur within 5'. Some allow it to be further away.

 

[Scott45]

Ok got it, thanks. I made a 4" trap arm and that section is pretty close (within a foot) to the 3" vent upstream so hopefully I'm good there.

Thanks for the information.

 

[Scott45]

IF you are in an "S" trap situation, it does NOT MATTER how close, or far, it is. Is that a "vent" or the drain from an upstairs bathroom?

Since I added the 4" trap arm there shouldn't be an S trap situation, let me know if that's not the case. I already glued it all up so I hope not.

The vent I mentioned is actually a vent. I have a single story home and that 3" pvc goes straight up through the roof with nothing else attached to it.