Can this be considered a wet vent or do the fixtures need vented individually?

Users who are viewing this thread

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
Currently adding a bathroom in the basement. I have read many forums on wet venting a bathroom group. I think this layout is a little different from most of the previous forums and diagrams. I am going to upload a couple sketches. I would appreciate the information on whether or not this would be considered a wet vent for the bathroom group or I would need to vent each fixture individually. I know it's a terrible quick scribble diagram but I think it does the job. The blue is the shower, brown is the toilet, and yellow would be the 2" vent/drain for the vanity. Thanks!

Screenshot_20220806-193144_Samsung Notes.jpg
 

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
I didn't think it was. I felt pretty dumb to ask but I figured why not. Looking at the diagram I can say it was indeed a dumb question. Thanks for the quick response! Very much appreciated! My only problem is I was planning on moving the existing soil stack further back (closer to the wall). If I did this I would not be able to run the shower drain behind the existing soil stack and I would have to run a branch vent to the shower. I take it there is no way around that unless I keep the stack where it is. One thing is for sure, I will leave it much better than when I opened it up.

20220721_233310.jpg
20220721_233321.jpg
20220722_182440.jpg
 

wwhitney

In the Trades
Messages
5,665
Reaction score
1,469
Points
113
Location
Berkeley, CA
If you have the depth available, you can run the shower drain over the building drain.

If not, as you are moving the stack, you could reroute the building drain around the whole bathroom group.

Cheers, Wayne
 

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
If you have the depth available, you can run the shower drain over the building drain.

If not, as you are moving the stack, you could reroute the building drain around the whole bathroom group.

Cheers, Wayne
Thanks so much! I was wanted to ask that but I didn't want to ask another dumb question. I am pretty sure I would have enough depth. If that is case, the shower drain is allowed to run over the top of the existing building drain? Is there a certain amount of distance they are required to be apart or can the shower drain be in contact with the building drain and what would be the best way (fitting) to tie the shower into the new 3" waste line? Sorry for all the qustion I just want to make sure this is done right and up to code. (In this area it is IPC). Thanks again.
-Josh
 

wwhitney

In the Trades
Messages
5,665
Reaction score
1,469
Points
113
Location
Berkeley, CA
If that is case, the shower drain is allowed to run over the top of the existing building drain?
Yes, however the total fall from the shower drain to where it joins the lav drain to be wet vented is limited to one pipe diameter. So that means the lav drain has to also initially (upstream end) be above the elevation of the building drain. Once the shower and lav join, the combined branch could hit the WC at the same elevation, or it could slope downward to a WC drain at the elevation of the branch drain.

Is there a certain amount of distance they are required to be apart or can the shower drain be in contact with the building drain and what would be the best way (fitting) to tie the shower into the new 3" waste line?
As for clearance between them, I don't have any underslab experience, but I would think you wouldn't want them touch. And you'd want at least 3" (preferably 4") of concrete above the shower drain.

The shower drain has to join the lav drain on the horizontal with a wye or combo.

Cheers, Wayne
 

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
Yes, however the total fall from the shower drain to where it joins the lav drain to be wet vented is limited to one pipe diameter. So that means the lav drain has to also initially (upstream end) be above the elevation of the building drain. Once the shower and lav join, the combined branch could hit the WC at the same elevation, or it could slope downward to a WC drain at the elevation of the branch drain.

These sketches should be much better than previous scribbling. Hopefully these are both error free and correct. If there is enough clearance to be above the existing, are these the 2 options you are explaining? Also is it better to use a wye combo than a wye by itself, or is it a preference? I apologize for being a pain and I can't say thank you enough.

- Josh

20220807_110302.jpg
20220807_110309.jpg
 
Last edited:

wwhitney

In the Trades
Messages
5,665
Reaction score
1,469
Points
113
Location
Berkeley, CA
So, a "combo" is a fitting where the hubs on the barrel (straight path) are 90 degrees from the side entry, It's a similar pattern to using a wye fitting plus a street 45 for the same spatial arrangement, just molded as a single piece. Anywhere you want to use a wye plus a street 45 you could use a combo instead; if I say wye, but you would need another 45 degrees of bend you can achieve that either way. This is distinct from a sanitary tee, which has less radius on the side entry.

My comment on elevation was that the shower trap arm has to go over the building drain, so the 2" wye where it joins the lav drain is at a higher elevation than the building drain. While the 3" wye where the bathroom group joins the building drain is obviously at the elevation of the building drain. So somewhere between those two, the bathroom branch drain has to drop 3"-5". That elevation change could be upstream of the 3x3x2 (or 3x2x3) wye where the WC joins the shower/lav, or it could be downstream of it. Either is OK.

Either of your drawings is fine, although your renderings of the angles wye/combo fittings don't seem quite right, perhaps as a side effect of trying to do them isometrically. If you are attempting to convey via those angles where the elevation drop occurs in each case, I'm not getting it. I think it would be easier to communicate with a 2-D plan view drawing, where the vertical pipes are just circles, and you just label where the elevation drop occurs.

Cheers, Wayne
 

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
My comment on elevation was that the shower trap arm has to go over the building drain, so the 2" wye where it joins the lav drain is at a higher elevation than the building drain. While the 3" wye where the bathroom group joins the building drain is obviously at the elevation of the building drain. So somewhere between those two, the bathroom branch drain has to drop 3"-5". That elevation change could be upstream of the 3x3x2 (or 3x2x3) wye where the WC joins the shower/lav, or it could be downstream of it. Either is OK.

Either of your drawings is fine, although your renderings of the angles wye/combo fittings don't seem quite right, perhaps as a side effect of trying to do them isometrically. If you are attempting to convey via those angles where the elevation drop occurs in each case, I'm not getting it. I think it would be easier to communicate with a 2-D plan view drawing, where the vertical pipes are just circles, and you just label where the elevation drop occurs.

Cheers, Wayne
Thanks, sorry if I overcomplicated that! I just wanted to make sure I understood what you were saying that the drawing and that all the fittings/elbows/adapters were correct. The angles are definitely wonky trying to draw it that way and led to miscommunication as well. I did understand what a wye and wye combo are. What I was trying ask was if it is better practice to use 1 method (only the wye) over they other (wye combo). In other words, should try to avoid using a wye combo unless it is absolutely necessary. Your reply answered that. James Henry's diagram looks like what I was trying to draw in the sketch labeled #1. Connecting the toilet drain upstream and dropping it to elevation downstream.

To James and Wayne, Thank you so much, again sorry for the headache. My last 2 questions should be much easier. Using James's diagram. #1- Where and what fitting is best to convert the 2" into 3"? # 2 - Is it correct that a rolled wye should not be rolled at an angle greater than 45 degrees when using it for elevation change in a wet vent?
 
Last edited:

wwhitney

In the Trades
Messages
5,665
Reaction score
1,469
Points
113
Location
Berkeley, CA
1) You can do it at the wye where the shower/lav joins the WC. Use a 3" wye with a 3x2 bushing in the straight inlet, since the WC is coming in the straight inlet (if I'm interpreting the isometric correctly).

2) That last wye labeled "rolled 45 degrees" could be rolled any amount that works, as long as everything is at least 2% slope.

Getting the angles right can be tricky. For example, say the combined branch drain is horizontally approaching the horizontal building drain so that it would hit the side inlet of a horizontal wye properly, except that there's an elevation difference. So you roll the wye up 45 degrees (of rotation) to account for the height difference, but now if you want to join the rolled wye to the horizontal branch, you'd need a 31 degree bend, which isn't made. You could do it via pair of 22.5 degree bends via trial and error. Or you could roll it up less than 45 degrees to find the roll angle that would allow a 22.5 elbow alone would work. Or if you have enough height difference, roll it up more than 45 degrees to the roll angle that would allow 45 elbow alone to work. Or change the angle of approach (as seen from above in plan view) to something other than 45 degrees.

The conceptually simplest way (to me) to join the branch drain and building drain when they are at different but very close elevations would be to use an "upright wye". That's what you get from a wye and a street 45 when you turn the street 45 so the two inlet are parallel. That configuration will have a fixed center to center distance between the two inlets. And so you just turn your horizontal branch drain to run parallel to the building drain at that same center to center distance, and then use an upright wye. That can accommodate any elevation between 0 and the center to center distance. Or if you need a greater center to center distance than an upright wye provides using a street 45, you can switch to a regular 45 and a short length of pipe.

Cheers, Wayne
 

Reach4

Well-Known Member
Messages
36,055
Reaction score
3,780
Points
113
Location
IL
Wye+45 can give some flexibility. Combo makes sure the wye and 45 are in the same plane.
 

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
Thanks everyone! I am getting all the fittings together to start working on this. I was laying everything out which leads me to another question. It should be a lot easier and hopefully the last one. It is related to creating sudden drops in elevation (like James's diagram) where the wye is rolled so the new group can drop into the existing plumbing. Are you allowed to use any elbow (except 90) to essentially do the same thing in any horizontal run of drain that needs to drop down under an obstruction? Similar to this. Thanks.

Screenshot_20220808-202635_Gallery.jpg
 

Terry

The Plumbing Wizard
Staff member
Messages
29,712
Reaction score
3,260
Points
113
Location
Bothell, Washington
Website
terrylove.com
Trap arms come off on the horizontal with a 2% grade, no fittings to change that.
A waste stack from a floor above can't wet vent anything downstairs.

Below is an example of a trap arm, with the vent above it.

index.php
 

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
Trap arms come off on the horizontal with a 2% grade, no fittings to change that.
A waste stack from a floor above can't wet vent anything downstairs.

Below is an example of a trap arm, with the vent above it.

Thanks, I guess I'm not asking the question the right way. Basically is it ok to make a change similar to in the circled section. Using 45's or other fittings. Instead of running one straight section of pipe on 1/4 slope straight from the P trap to the stack. (the shower is vented just not included in the diagram)
 

Attachments

  • Screenshot_20220808-204025_Chrome.jpg
    Screenshot_20220808-204025_Chrome.jpg
    24 KB · Views: 39

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
After the vent, then you can make changes. Between the trap and the vent, that has to have the 2% grade.

Sorry about that. This is all I was trying to ask. I should have did it like this the first time. The black is the current plumbing how it is now. The red is the change in elevation I would like to make. I just wanted to make sure it was ok to change elevation like that in any run of horizontal drain. Thanks for the answer.
 

Attachments

  • Screenshot_20220808-205717_ibisPaint X.jpg
    Screenshot_20220808-205717_ibisPaint X.jpg
    27.2 KB · Views: 40

JCar915

New Member
Messages
12
Reaction score
0
Points
1
Location
Ohio
That drain looks deep enough to accomplish that. It can tie in less than 45 degrees vertically.

Thanks James. I'm actually using your diagram and it will work. The top of the existing is far enough down. This was actually about my upstairs shower. It has to be re routed since the stack is being pushed back. I was going to go under a duct into the stack.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks