DWV Horizontal Layout and Venting Help

Help Support Plumbing Forums:

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
I would just be cutting out the wet vent section of that!? Then it would just be a matter of pushing that vtr up as high as I can in the bay to bring my branches in and keep them in bays. I could switch all lavs over to two inch drains and tub two inch, two inch trap with bushing ? or 2 line with 1 1/2 trap. Either way I could get a few lines in on it and I’m 3” for what at most 5 or 6 dfu. And I think I can do both wc with one 1 1/2 under IPC.
And that 3 inch keeps me vented until it hits my horizontal main, it works....now just tying the two wcs together so they both use same vent just getting that one over the stack fitted right to share common vent with the other And tying it into stack.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
And that 3 inch keeps me vented until it hits my horizontal main, it works....now just tying the two wcs together so they both use same vent just getting that one over the stack fitted right to share common vent with the other And tying it into stack.
And that 3 inch keeps me vented until it hits my horizontal main, it works....now just tying the two wcs together so they both use same vent just getting that one over the stack fitted right to share common vent with the other And tying it into stack.
The red portion of the picture above is "wet vented" the main is your "vtr" pipe.
so personally I have never had to do it but I could easily bump that vtr up higher by putting hub of wye combo up into and probably above bottom plate to give me the extra I need, it’s a 2x6 plate so....what do you think inspector would say.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
The red portion of the picture above is "wet vented" the main is your "vtr" pipe.
Just s side thought but when I bring my wcs into my stack they have to come in higher than everybody else or first since their coming in separate? Correct. And thanks again JG
 

JG plumbing

Well-Known Member
Joined
Mar 26, 2021
Messages
997
Reaction score
318
Location
Iowa
I'm not 100 percent sure what your asking.

Sketch what your thinking. The whole system.

I didn't have the wc draining seperate. Everything still drains into the lower horizontal run that you have below the joists. You just turn your dry vent into a combination drain /vent and the toilets vent individually. As long as you have a combo (wye 45) or tee or just a wye and 45 looking up that should vent the other fixtures. In my scenario you want the horizontal portion of the pipe you have labeled vtr as low as possible (which I know is different than what I said before) so the other fixtures can drain into it.

I think we're getting less clear as we get more specific, lol.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
I'm not 100 percent sure what your asking.

Sketch what your thinking. The whole system.

I didn't have the wc draining seperate. Everything still drains into the lower horizontal run that you have below the joists. You just turn your dry vent into a combination drain /vent and the toilets vent individually. As long as you have a combo (wye 45) or tee or just a wye and 45 looking up that should vent the other fixtures. In my scenario you want the horizontal portion of the pipe you have labeled vtr as low as possible (which I know is different than what I said before) so the other fixtures can drain into it.

I think we're getting less clear as we get more specific, lol.
No I’m following you, after I thought about it and looked at your drawing again I saw that you had figured the wcs on that same main 4” horizontal which is all the same I just had a separate line because they were so off set to the front but I can still get vent on a and getting the left one hooked on isnt to bad it’s the one by the stack that is giving me a hard time tying into that main, I even tried doing away with the angle and moving the line down to drop in with a sweep 90 hoping it would give me enough room to tie it in before the 90 but the 90 literally lands right above it. I could do a wye in the 45 angle pointed up but I don’t think that would be considered vented? The other with vtr I had myself coming in more horizontal to horizontal when I really can just roll a wye combo up and drop in almost from the top maybe as little less. I think just a regular wye might work for some of the connections. No we’re still on same page.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
I'm not 100 percent sure what your asking.

Sketch what your thinking. The whole system.

I didn't have the wc draining seperate. Everything still drains into the lower horizontal run that you have below the joists. You just turn your dry vent into a combination drain /vent and the toilets vent individually. As long as you have a combo (wye 45) or tee or just a wye and 45 looking up that should vent the other fixtures. In my scenario you want the horizontal portion of the pipe you have labeled vtr as low as possible (which I know is different than what I said before) so the other fixtures can drain into it.

I think we're getting less clear as we get more specific, lol.
Not vented right, especially if I am trying to use vent from other one.
 

Attachments

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
I think you'll want to offset the horizontal main to get in line with the second toilet. Use a tee, then offset into the stack.
Did a sketch up, I know you had another clean out on the vtr depicted in yours and it definitely needs another one on the first floor somewhere but in runs in between tub wall and wall vanity will be pushed against, I’m still thinking though figure something out. Lining the wcs up shouldn’t be hard even the one by the stack, I am disconnected still going into septic so I can just add a little length and pull out more to line up, and the jog I think I can make with a 45 out the top of sanitary tee and shoot in, figured from wc vent to wc at stack is about 4 and a half feet, and my other runs are short, but still think switch to 2” just to cover basses, use 2” trap for tub with bushing go up 1 1/2. Theirs no need to back vent lav I am running into vtr ?. Thanks again JG you have been a huge help can’t thank you enough.
 

Attachments

JG plumbing

Well-Known Member
Joined
Mar 26, 2021
Messages
997
Reaction score
318
Location
Iowa
The lav does need to be back vented if the trap is above the floor. The only things that won't need it are the ones with traps below the floor and the toilets. I'm glad you asked that.

I've been doing this in between caretaking for my 18 month baby, my girlfriend who broke her back and ribs on a horse, my 16 year old daughter (who doesn't need a lot of care), and work. I'm kind of half paying attention. To all of you lol.
 
Last edited:

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
You definitely have a lot on your plate, when you said you were busy, you were definitely not kidding. Thanks for giving what time you must have to helping me out.
Kinda figured the lav still had to be back vented but wanted to double check did a last couple sketches but it’s about as good as it’s going to get. Just thinking though on the Lines running to vtr I bumped them up to 2”, do I have to back vent those lines 2” since it’s a combo vent drain?
Again thanks for the feedback and time JG, ever need anything I can help you with let me know.
 

Attachments

JG plumbing

Well-Known Member
Joined
Mar 26, 2021
Messages
997
Reaction score
318
Location
Iowa
So when you do a combination system all the lines have to be one pipe size larger than the minimum to keep space for the air to run above the water. I'm not sure on the minimum pipe sizes in ipc. For upc you technically would need to run a 3" "trap arm" for the shower since 2"is the minimum and they don't make 2.5" pvc anymore (and they don't allow for it in the sizing guidelines).

I think this is one where I would check with the inspector. Running 3"pipe for such a short run that is that close to the vertical vent piping seems excessive, but I think it's technically right by upc.

Just stay one pipe size larger and you don't need to back vent them.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
So when you do a combination system all the lines have to be one pipe size larger than the minimum to keep space for the air to run above the water. I'm not sure on the minimum pipe sizes in ipc. For upc you technically would need to run a 3" "trap arm" for the shower since 2"is the minimum and they don't make 2.5" pvc anymore (and they don't allow for it in the sizing guidelines).

I think this is one where I would check with the inspector. Running 3"pipe for such a short run that is that close to the vertical vent piping seems excessive, but I think it's technically right by upc.

Just stay one pipe size larger and you don't need to back vent them.
Think I should be good with 2” it what IPC uses for wet vent and it reads half the diameter of the largest line which in this case is my 4” main, man upc is tough on you guys. I was just concerned on my back vents because of my 2x4 walls if I had to back vent 2” but the way it reads is you can run 40” of 1 1/2 and says nothing more so I’m thinking run the 40” then bump it to 2” for the one lav on the vtr vent, the other lav isn’t on it so I can just run normal 1 1/2 anyway.
 

Attachments

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
So when you do a combination system all the lines have to be one pipe size larger than the minimum to keep space for the air to run above the water. I'm not sure on the minimum pipe sizes in ipc. For upc you technically would need to run a 3" "trap arm" for the shower since 2"is the minimum and they don't make 2.5" pvc anymore (and they don't allow for it in the sizing guidelines).

I think this is one where I would check with the inspector. Running 3"pipe for such a short run that is that close to the vertical vent piping seems excessive, but I think it's technically right by upc.

Just stay one pipe size larger and you don't need to back vent them.
So I made a couple changes wanted to run it by you.
1) I brought the left lav over to wet vent the left wc and did away with dry vent?
2) I am just going to run separate kitchen/washer line and hook into stack down low?
Just wanted to see your thoughts, and thanks again for the the guidance and help I know your busy. It’s much appreciated, anything I can ever do , let me know.
 

Attachments

JG plumbing

Well-Known Member
Joined
Mar 26, 2021
Messages
997
Reaction score
318
Location
Iowa
That should be fine. I'm not crazy about seperate drains for the kitchen sink and dishwasher. I like the sink to wash the piping for the dishwasher and vice versa. You get plenty of flow and self cleaning that way. But it's your call. The simpler you can make the piping the easier to get a rod into later in the event of a plug.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
I totally get what you are saying it’s the most ideal way it’s getting it tied into the main horizontal where everything seems to be meeting, in IPC anytime a kitchen or washer enter what a drain line carries, then any bathroom group fixture that joins it must already have been vented so I have to keep it separate until everything is technically vented. So to try and give it a shot, because I believe in my set up I would have to come by with the kitchen line past my left lav past wc and past the dry vent for wc then I believe I could tie it in because everything after that the right lav, tub, and shower are all vented already on the small horizontal coming in which only leaves the wc on end that dumps into top of stack, so to my thinking I have to tie kitchen washer line in between the left wc and where my other vtr horizontal comes in, assuming the wc that dumps into top of stack is vented so to make a little room basically I am going to take the left lav which comes in upstream, use it as a wet vent for the left wc, take the dry vent out which will free up a little room and hook kitchen line in.? Problem one is right wc is technically unvented then I think, but problem two came today when I realized I can’t get the tub hooked on to the 3”vtr horizontal becss as use it’s pushed pretty tight against the right joist that I can’t get a wye on without drilling 3” hole in joist and half the wye side branch would end up in the middle of joist for my connection. Guess I am thinking that I could just run tub line down to main horizontal and use it to wet vent right wc. Unless I am not seeing somewhere that the right wc would already be vented somehow already, either way tub has to come all the way down and get back vented I guess because it just ain’t fittin.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
I totally get what you are saying it’s the most ideal way it’s getting it tied into the main horizontal where everything seems to be meeting, in IPC anytime a kitchen or washer enter what a drain line carries, then any bathroom group fixture that joins it must already have been vented so I have to keep it separate until everything is technically vented. So to try and give it a shot, because I believe in my set up I would have to come by with the kitchen line past my left lav past wc and past the dry vent for wc then I believe I could tie it in because everything after that the right lav, tub, and shower are all vented already on the small horizontal coming in which only leaves the wc on end that dumps into top of stack, so to my thinking I have to tie kitchen washer line in between the left wc and where my other vtr horizontal comes in, assuming the wc that dumps into top of stack is vented so to make a little room basically I am going to take the left lav which comes in upstream, use it as a wet vent for the left wc, take the dry vent out which will free up a little room and hook kitchen line in.? Problem one is right wc is technically unvented then I think, but problem two came today when I realized I can’t get the tub hooked on to the 3”vtr horizontal becss as use it’s pushed pretty tight against the right joist that I can’t get a wye on without drilling 3” hole in joist and half the wye side branch would end up in the middle of joist for my connection. Guess I am thinking that I could just run tub line down to main horizontal and use it to wet vent right wc. Unless I am not seeing somewhere that the right wc would already be vented somehow already, either way tub has to come all the way down and get back vented I guess because it just ain’t fittin.
I like the idea of the kitchen and washer line and the flow cleaning pipe on way through, just with this set up by the time I tie it it I am literally three feet from main vert stack, and I’m not washing the first wc with it because I am already past it, plus theirs the lav behind that wc to help wash that section behind wc, then the other wc is dumped right into top of stack so no real wash their, so really I am just washing what comes from 3”vtr branch , lav, shower and tub wherever that dang thing fits in now. Be nice to each if anything get built up from e we hen it enters and any residual left from left wc downstream but other than that it’s just drain water. Still would like to do it that way just take a little maneuvering of things.
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
NO

the vent has to tie into the drain line BEFORE the bathroon not afterView attachment 29286
Thanks for input Frodo, and that’s exactly why I couldn’t really set it up like that. Ended up going with just a regular horizontal wet vent layout and still keep everything in joist bays as much as possible, and with my limited available walls to use in first floor for back vents I hope my setup is ok, any feedback and critique would be welcome and appreciated. Basically two lavs 2” and backvented 2”, one lav wet venting first bath group, other lav wet venting second bath group. I know in horizontal wet vent my connection from my horizontal branches coming into the main horizontal in back wall they want you at a true horizontal to horizontal connection, but the best I can do without totally dropping out of bays is less than 45? And even then my traps are low but if it works then its fine. Thoughts and opinions. And I did away with the vtr because it was serving no real purpose, and can just tie vents in up top and take out through.
 

Attachments

frodo

Just call me Macgyver
Professional
Supporting Member
Joined
Sep 28, 2014
Messages
8,539
Reaction score
2,931
Location
right here right now, over there later on.
only proplem i see, is the wye for the tub looks to be to low, the trap is going to be below ceiling

the other is the kiytchen sink. you have ''washer'' written beside the sink. and a measurement of 3'
is this the dish washer or clothes washer? if it is the dishwasher. it will drain into the sink tap using a wye branch fitting. if it is the clothes washer. you are going to have suds baking up into the sink. the drain tie in needs to be down stream of the sink by 5' it is called, suds relief
 

CAdamL

Member
Joined
Apr 14, 2021
Messages
24
Reaction score
3
Location
New york
only proplem i see, is the wye for the tub looks to be to low, the trap is going to be below ceiling

the other is the kiytchen sink. you have ''washer'' written beside the sink. and a measurement of 3'
is this the dish washer or clothes washer? if it is the dishwasher. it will drain into the sink tap using a wye branch fitting. if it is the clothes washer. you are going to have suds baking up into the sink. the drain tie in needs to be down stream of the sink by 5' it is called, suds relief
Thanks for feedback Frodo, the wye on tub is low and my trap is a little below bay, but I didn’t want to turn it up to much, think I would be ok to turn it up a little more towards 45?. Their is a dishwasher but like you said it will hook to sink. The depicted is a clothes washer and I have not tied that or kitchen sink into main 3” yet, kitchen sink is 2” and washer 2” running separately into a three inch and should be to hard to bring washer in downstream of sink. With that being said the rest doesn’t look to bad?
 

Latest posts

Top