Ran into a small problem replacing drain.

[phospholipid]

Yeah, so there is a beam above (and below) the sani-T so it couldn't go any higher (or lower) and trap that the straight comes out of wouldn't go any lower, so the only way to make the angles meet was to figure out where to have a slight turn down at the right spot. It's not the weirdest angles I've had to make with a drain in the house, but the water is pitched down all the way.

 

[Cacher_Chick]

That is a problem in that you cannot jog the trap arm down between the trap and the vent. It can cause to trap to siphon, and would be flagged by any competent inspector.

 

[Sponsor]

 

[phospholipid]

That is a problem in that you cannot jog the trap arm down between the trap and the vent. It can cause to trap to siphon, and would be flagged by any competent inspector.

I really appreciate that insight. Since this is PVC and so so easy to redo, I may pull that and do it again. Honeslty, I don't mind in the name of learning. I just took a look, and the board under the trap is non structural. So it won't be difficult at all to saw it out, lower the trap by about 2" and then have that arm go into the T without a jog.

 

[Smooky]

Another option would be to vent it somewhere between the trap and before it jogs down.

Here is a little plumbing guide. It shows a shower drain on page 6 that jogs down after the trap and it shows a vent off the trap arm that is similar to what you might be able to do:

Plumbing-and-Trenching-for-Homeowners---2018 (klickitatcounty.org)

 

[phospholipid]

Another option would be to vent it somewhere between the trap and before it jogs down.

That actually may be easier. Like, way easier.

 

[Smooky]

Yea, That is what I thought.

 

[phospholipid]

Another option would be to vent it somewhere between the trap and before it jogs down.

Here is a little plumbing guide. It shows a shower drain on page 6 that jogs down after the trap and it shows a vent off the trap arm that is similar to what you might be able to do:
Plumbing-and-Trenching-for-Homeowners---2018 (klickitatcounty.org)

This handout is fantastic. Upon reading through it, I'm noticing that the contractor who did the kitchen drains for the previous owner used the wet venting style, labeled WRONG, for those two sinks. It was on my list to redo, so now I can redo it correctly. Thanks for this!

 

[Smooky]

You came to the right place. We're glad to help you.

 

[Cacher_Chick]

If you are going to revent, the new vent take-off must rise vertically at least 42" above the floor level before having any transition to horizontal.

 

[hj]

Good job of creating an "illegal 3/4 S trap" which would be IMMEDIATELY rejected if you had had the required inspection.

 

[phospholipid]

Good job of creating an "illegal 3/4 S trap" which would be IMMEDIATELY rejected if you had had the required inspection.

So, I think that I've been clear that I'm new to this. Since, as an admitted neophyte, I don't really know the jargon, would you mind unpacking that assessment for me? I'm happy to learn and re-do it.

 

[Smooky]

I think HJ is talking about the S-trap you created In the picture Plumb1 in post #16 where you angled down 45 and then went into a tee. The fix for that is to add a vent as we already discussed.

 

[Jadnashua]

The trap arm CANNOT go down (well, not more than 1/4"/foot-essentially horizontal) before the vent.

 

[phospholipid]

Yeah, I think I understand his terms now. My trap arm is pitched at exactly 1/4" over it's 12" run, and then (unfortunately, as I didn't realize this was a problem) it drops into that 45º then laterally into a 90º which goes into into the sani-T. As you've mentioned, if I put the vent right at the start of the trap arm I can alleviate a siphon problem.

My understanding is that for the vent, it has to be 42" vertical, but it also seems that "vertical" means it can be up to 45º of an angle. Is that correct? The old vent pipe which is still there is perfectly vertical and it's cut about 36" away from the work. It won't be too difficult to insert a wye in that arm and can get there at 45º or straighter.

 

[Cacher_Chick]

Yeah, I think I understand his terms now. My trap arm is pitched at exactly 1/4" over it's 12" run, and then (unfortunately, as I didn't realize this was a problem) it drops into that 45º then laterally into a 90º which goes into into the sani-T. As you've mentioned, if I put the vent right at the start of the trap arm I can alleviate a siphon problem.

My understanding is that for the vent, it has to be 42" vertical, but it also seems that "vertical" means it can be up to 45º of an angle. Is that correct? The old vent pipe which is still there is perfectly vertical and it's cut about 36" away from the work. It won't be too difficult to insert a wye in that arm and can get there at 45º or straighter.

If you can do that, it will fix the problem.

 

[Smooky]

Yes, you can be at a 45 degree angle and tie in to the vent at 42 inches above the floor of higher.

 

[phospholipid]

When you say "tie in to the vent at 42 inches above the floor of higher" does that include tying in vertically? I thought the 42" was only for tying in horizontally. In my situation, I would run about 30º from vertical and then tap directly into an already perfectly vertical existing vent pipe--no horizontal necessary.

 

[Jadnashua]

The vent MUST travel at least 42" above the floor OR 6" above the flood plane of the highest trap connected to that vent, whichever is higher before it can go horizontal. A 45-degree run is considered vertical.

 

[phospholipid]

The vent MUST travel at least 42" above the floor OR 6" above the flood plane of the highest trap connected to that vent, whichever is higher before it can go horizontal. A 45-degree run is considered vertical.

So I'm good then since I won't be going more than 45 and I'll be hitting a vertical. The event doesn't go horizontal until the third floor, ten feet above.