After much planning, Questions, and Answers I installed the drainage plumbing in my home. I had our local mechanical inspector over and he was happy with everything upstairs however when he looked downstairs he was concerned. The first thing he said was that I should have hired a professional plumber. Then he said the drainage from the shower is an illegal S trap and that it needs a vent.
He proceeded to say that the toilet drainage needs a vent as well.

The 2" drain on the shower runs 5" Horizontally after the P trap (more than double the diameter of the pipe) before the 90 going down. The total length of pipe is about 2' before it goes into the stack.

The 3" Toilet drain runs only 5' before it hits the main stack.

From what I know the rule of thumb for S traps is to make the horizontal distance no less than twice the diameter of the pipe.
The critical venting distance for 2" pipe is 5'.
The critical venting distance for 3" pipe is 10.
Are these applicable rules in my case?

I'm in Everett Washington.
Not sure exactly what plumbing code I fall under.
A couple things about the arrangement I used are that the space I have to work with is extremely tight. I could fairly easily put a vent on the toilet however the shower will be tricky. The P trap bottom will currently hit the drywall ceiling and the P trap top is about .25" from the floor above.

You have a "S" trap built in the shower and "S"{n trap's are illegal . However, if there was nothing draining into the stack from above you could have raised the sanitary tee all almost level with the "P" trap and the inspector would have passed it. The toilet's only five feet away from the stack and if you had connected the shower correctly then toilet would have been wet vented by it. I believe you fall under UPC and they mow allow wet vents.
Solution; Cap off the old tee and install a new sanitary tee in the correct location.
Good luck, Tom

Here is a more accurate representation. Could I put vents in the green locations? The inspector said that I could use 1.5" for the toilet vent is that OK?


Yet even more accurate and easier to read.

Your toilet is OK as is, the vent for the shower can be 1.5 inches, the vent on a toilet can be no smaller than 2".

Quote:

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Originally Posted by truck 41

your toilet is ok as is, the vent for the shower can be 1.5 inches, the vent on a toilet can be no smaller than 2".

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Do you think a vent on the toilet is not needed? There is a 1.5" vent running Horizontal in the wall above the toilet drain so I would have to change things around in order to get a 2" pipe in there. I could tie the 1.5" vent in from the shower though.

If that horizontal vent is a dry vent it's acceptable to revent both the toilet and the shower back to it. If the inspector OKed a 1 1/2" vent for the toilet then go for it. Note: your toilet's already wet vented by the lavatory. Good luck, Tom

Some pics from the original plumbing.
There was one 2" extremely wet vent servicing this setup.
Not to mention the copper and galv. Were a huge mess.

what's dumping into the 4x2 double wye next to the water heater?

That was the washer
The 2" galv. pipe in the top right was the kitchen drain.
It drained very slowly and when I took it out there was probably about a .5" opening. The .75" galv. water had a.25" water way.
Just before we purchased this place someone had done some work in the upstairs bathroom. They attempted to glue pvc to abs with abs cement. Which didn't leak until I touched it and the glue separated from the pvc. There were a couple dead ends which were caped with old rags and socks. Lots of fun stuff.

Hi, I think there is a simple but elegant solution here. Bear with me for a moment. I'm wondering if what you've shown as a 3" stack is carrying waste from upper floors. If so, it is not a legal vent under the UPC, and that is one of your issues. The shower drain needs to reach a vent , within 5' horizontally after leaving the trap for a 2" line, sloping 1/4" per foot. You can't drop down until after venting. The green lines for the lav look OK to me. The toilet has a 2' trap arm (or fixture arm), not 5'. The 3' drop to the "closet bend" isn't part of that computation. The toilet needs to be vented at least two pipe diameters down the fixture arm from the closet bend, so I'm guessing the green vent you showed is in the wrong position.

So consider this... you can configure things "wet vented" with a single 2" vent to the shower and it's drain feeds the toilet drain as both the shower drain and a "wet vent" for the toilet. Just vent the shower as you show in green, then remove the 6" connection to the stack, and continue the shower vent/drain vertically down to the 3" toilet drain and connect with a 3'x2" wye and 1/8 bend. Looks like a piece of cake on your detailed diagram. :)