DWV layout (revised)

[OddsAndEnds]

If anybody has the time to take a look and give me any feedback and advice it would be grateful, hope I am not to far off base and on track with the layout in general. I am under IPC. Had to rework layout and this is what I got so far. Thanks in advance for any suggestions and guidance.

 

[wwhitney]

A few comments:

The two solid blue lines labeled VTR (vent through roof?), you've extended them down to connect to the drains. But they only need to extend down to lowest vent (dashed blue line) that connects to them. The extra connection between the vent and the drain that isn't specific to any fixture is not required.

Under the IPC , the washer drain needs to increase in size to 3" once it joins another drain, in your drawing that would be the kitchen sink drain. So if it's easier to run two parallel 2" drains than one 3" drain through some of your framing, you could move the combination point further downstream. [The kitchen sink by itself could be a 1-1/2" drain, but 2" is better.]

You can't join a WC to a drain that has a kitchen sink or washing machine draining into it without first venting the WC. The WC can be wet vented via the lavs, but that lav/WC joint has to be upstream of the kitchen or washing machine coming in.

So for the left WC, you could keep its drain separate from the kitchen sink/washing machine/left lav drain, then have your vertical dry vent takeoff, then join the left WC drain to the kitchen sink/washing machine/left lav drain. Or you could keep the left lav separate from the kitchen sink/washing machine, join that lav to the left WC drain, wet venting the left WC via the the left lav, eliminate the left WC dry vent takeoff, and then join the left WC/left lav with the washing machine/kitchen sink.

For the right WC, you'd want to keep the right lav/shower/tub drain separate from the kitchen sink/washing machine and have it join the right WC before the kitchen sink/washing machine drain comes in.

Cheers, Wayne

 

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[OddsAndEnds]

A few comments:

The two solid blue lines labeled VTR (vent through roof?), you've extended them down to connect to the drains. But they only need to extend down to lowest vent (dashed blue line) that connects to them. The extra connection between the vent and the drain that isn't specific to any fixture is not required.

Under the IPC , the washer drain needs to increase in size to 3" once it joins another drain, in your drawing that would be the kitchen sink drain. So if it's easier to run two parallel 2" drains than one 3" drain through some of your framing, you could move the combination point further downstream. [The kitchen sink by itself could be a 1-1/2" drain, but 2" is better.]

You can't join a WC to a drain that has a kitchen sink or washing machine draining into it without first venting the WC. The WC can be wet vented via the lavs, but that lav/WC joint has to be upstream of the kitchen or washing machine coming in.

So for the left WC, you could keep its drain separate from the kitchen sink/washing machine/left lav drain, then have your vertical dry vent takeoff, then join the left WC drain to the kitchen sink/washing machine/left lav drain. Or you could keep the left lav separate from the kitchen sink/washing machine, join that lav to the left WC drain, wet venting the left WC via the the left lav, eliminate the left WC dry vent takeoff, and then join the left WC/left lav with the washing machine/kitchen sink.

For the right WC, you'd want to keep the right lav/shower/tub drain separate from the kitchen sink/washing machine and have it join the right WC before the kitchen sink/washing machine drain comes in.

Cheers, Wayne

Thanks for the comments and look over Wayne, sounds like the bathroom layout isn’t to bad, the vtr running all the down is already their so, even though not required it can still stay? Couple questions if you have time, I am back venting both lavs in 1 1/2 and the wc in 1 1/2 because of 2x4 walls, I’m good their? Bump them up as soon as I can. Guess I was thinking the lav hooked to where my vtr comes down would need to be 2”back vent? at least. As for the kitchen and washer I didn’t really like the idea of hooking together with the bathroom groups to begin with but it’s a long run, thinking I might just run separate line and hook into stack, run 2” for both into 3” and hook in, and I would have to be the most downstream on stack with that? Even before my second floor run ties in. Just put co on four inch by the last lav branch. Things are tight in the joist bays and main horizontal already without adding the washer and kitchen.

 

[wwhitney]

Per ? in your previous post.

1) Yes
2) 1-1/2" is an adequate IPC vent for any drain line 3" and smaller, as I understand it.
3) No need for 2" vent that I'm aware of.
4) Yes, once the kitchen or the washing machine is part of what a drain line carries, then any bathroom group fixture that joins it needs to have already been vented. Keep them separate until the bathroom group fixtures are vented.

Cheers, Wayne

 

[OddsAndEnds]

Per ? in your previous post.

1) Yes
2) 1-1/2" is an adequate IPC vent for any drain line 3" and smaller, as I understand it.
3) No need for 2" vent that I'm aware of.
4) Yes, once the kitchen or the washing machine is part of what a drain line carries, then any bathroom group fixture that joins it needs to have already been vented. Keep them separate until the bathroom group fixtures are vented.

Cheers, Wayne

Thanks in advance Wayne, so after your critique and advice I did make a couple changes,
1) I brought the left lav over and used it to wet vent the left wc, and did away with the dry vent?
2) I decided to run a separate kitchen washer line and hook into the stack separately with it down low?
I think I am good with both changes but wanted to see what you thought if you had a min to look over. Thanks again for your time and guidance.

 

[wwhitney]

Looks good to me. A couple comments:

- No real opinion on COs and where they should be, either the rules or what would be useful. But as long as they are sealed properly and accessible, there's no operational downside.

- On the left lav, looks like you've brought it to the right to join the 3" WC/CO line downstream of the WC. You could just join it upstream of the WC if you want. With the caveat:

I think some people have the opinion that the WC shouldn't join a horizontal wet vent from above, and so would prefer the horizontal junction you have drawn. But I don't see anything in the IPC that would require that ( there's a section in the IRC that does, if your jurisdiction has adopted the plumbing portion of the IRC, and you don't have the option to use the IPC), nor do I see how it makes any difference in performance in your case (I can see it when there's a downstream fixture that depends on the upstream lav for wet venting, if you assume that the WC deluge will block the entire pipe cross section).

Cheers, Wayne

 

[OddsAndEnds]

Looks good to me. A couple comments:

- No real opinion on COs and where they should be, either the rules or what would be useful. But as long as they are sealed properly and accessible, there's no operational downside.

- On the left lav, looks like you've brought it to the right to join the 3" WC/CO line downstream of the WC. You could just join it upstream of the WC if you want. With the caveat:

I think some people have the opinion that the WC shouldn't join a horizontal wet vent from above, and so would prefer the horizontal junction you have drawn. But I don't see anything in the IPC that would require that ( there's a section in the IRC that does, if your jurisdiction has adopted the plumbing portion of the IRC, and you don't have the option to use the IPC), nor do I see how it makes any difference in performance in your case (I can see it when there's a downstream fixture that depends on the upstream lav for wet venting, if you assume that the WC deluge will block the entire pipe cross section).

Cheers, Wayne

Thanks Wayne, For some reason I was thinking the lav had to be downstream of the wc. So from that lav to the wc it’s only like 4 feet, I could bump lav line to 2” just run it straight into Horizontal main were it is and do a combo, where I could actually roll it down to less than 45 and I would be good?
It does sound like their is a pretty good debate on how the code says to enter on a horizontal wet vent and what people actually think is still sufficient.
Thanks again Wayne much appreciated.

 

[wwhitney]

For some reason I was thinking the lav had to be downstream of the wc.

A philosophical comment: absent an external reference, for the two upstream most fixture drains on a branch, you can't say which fixture is upstream of the other. All you can do is identify the point at which the two fixture drains combine, and say that is the upstream most juncture.

Now in your case you have a CO, so you can use the CO as an your external reference, and say whether the lav joins between the WC and CO, or after the WC and CO. But the presence of the CO doesn't change any rules about how the lav and WC can join each other.

So from that lav to the wc it’s only like 4 feet, I could bump lav line to 2” just run it straight into Horizontal main were it is and do a combo, where I could actually roll it down to less than 45 and I would be good?

Yes, sounds right, other than the issue below.

It does sound like their is a pretty good debate on how the code says to enter on a horizontal wet vent and what people actually think is still sufficient.

Yeah so if the idea of the WC entering the horizonal wet vent from above concerns you, you could stick with the drawing you made. Or if you have the lateral space available, you could shift the CO-left WC section to the side so the WC closet flange can hit a closet bend and then a horizontal wye (or I guess you could do a 60 and a wye rolled up 45 degrees).

Cheers, Wayne

 

[OddsAndEnds]

So after a couple different layouts I am still having a difficult time tying everything in it is definitely not the most ideal set up but keeping things up in joist bays and tucked close to wall are all a consideration being used. I have everything stubbed down and two lavs run in 2” and backvented 2”. The best I can do with some of my connections from the horizontal to horizontal is only less than 45 with a wye combo can’t get a true horizontal to horizontal connection. The wc to the right is above stack and I have no real means to back vent it, and realize in its current setup still left unvented. Nothing is set everything is mocked up and only dry fitted, my stack is only dry fitted and I can reconfigure, I still need to bring in the washer and kitchen line from the far end and tie it in and would like it to wash some of the main line but by the time I am past the point I can tie into horizontal with it I am almost at the vertical stack anyway. Realize I am going to have to start drilling joist to bring some stuff together and really just want to make sure I have it all correct before doing so. Backventing has been difficult because I have limited walls in first floor that dont have tripple and quadruple joist/truss sitting directly on top of them, I could possibly back vent tub and shower if need be but have no way to back vent wc at all, so I’m thinking I can bring left lav down through joist bay to wet vent first wc and the second wc to right I could use some help with. Any help at this point would be welcome, and greatly greatly appreciated. Had a a plan to bring in some stuff to the center 3”vtr but not sure if that is the best route. Realize that if I was to bring kitchen, washer in onto the stack separately I would have to reconfigure stack to bring it in at most downstream if I am thinking correctly.

 

[Reach4]

Realize that if I was to bring kitchen, washer in onto the stack separately I would have to reconfigure stack to bring it in at most downstream if I am thinking correctly.

You must not bring in before bathroom wet venting. Once everything is vented, you should be able to join the flows in any order.

 

[wwhitney]

Can you post a floor plan of the first floor?

You can join everything at the stack more compactly than you have. I think you just need two 3" horizontal runs below the joists. One is for both first floor bathroom groups. The other is for the kitchen sink and washer, which can pick up the second floor as well. As long as the latter joins the stack below the former, the WC sitting above the stack will be wet vented as part of the two bathroom groups.

Cheers, Wayne

 

[OddsAndEnds]

Can you post a floor plan of the first floor?

You can join everything at the stack more compactly than you have. I think you just need two 3" horizontal runs below the joists. One is for both first floor bathroom groups. The other is for the kitchen sink and washer, which can pick up the second floor as well. As long as the latter joins the stack below the former, the WC sitting above the stack will be wet vented as part of the two bathroom groups.
F
Cheers, Wayne

This is the first floor layout, the tub 2x6 wall is where the 3” second floor goes up And the 3” vtr goes up through, vtr on left ,2nd on right, tub and valve in middle. The lav on right I was able to get a vent going up drain landed right next to stud so I followed it straight up with vent but had to come to top of wall and 90 into closet then 90 back up to get around the quadruple joist sitting right on top of wall. Realize the vtr that runs all the way down is kinda pointless. Lav on left comes up 42 flood rim, horizontal and up. I see what you mean by being able to just do the two three inch, I could run the washer kitchen into second floor where it comes across horizontal? Can I do a wye and run it right into it and go to stack, then one 3” for both first floor baths, wet vent first group with lav on left and wet vent second group with th lav coming down on right, and the right wc if I came down into a sanitary tee, with my 3 “ coming over horizontal into it and into stack stack vertices from bottom of tee I would be vented? Am I on the right track.

 

[wwhitney]

I was looking for an unskewed floor plan that I could mark up for you. Ideally showing the joists below and the location where the stack is below. And the locations in the framing above where you can put vents.

Your run on paragraph is a bit hard to follow, but my suggestion on the drain side is based primarily on the photo in which you marked "2nd floor". And that is to run the washer/kitchen sink branch across the joists just in front of the 3" bathroom group line, then join it into the 2nd floor, then the combined drain can go to the stack (and likely a bit more directly than you have, unless, the stack is already glued up, in which case it's probably not worth changing).

Then on the bathroom groups, bring the 3" line across to a sanitary tee over the stack or under the WC above, jogging the stack above or below the san-tee, respectively.

Cheers, Wayne

 

[OddsAndEnds]

I was looking for an unskewed floor plan that I could mark up for you. Ideally showing the joists below and the location where the stack is below. And the locations in the framing above where you can put vents.

Your run on paragraph is a bit hard to follow, but my suggestion on the drain side is based primarily on the photo in which you marked "2nd floor". And that is to run the washer/kitchen sink branch across the joists just in front of the 3" bathroom group line, then join it into the 2nd floor, then the combined drain can go to the stack (and likely a bit more directly than you have, unless, the stack is already glued up, in which case it's probably not worth changing).

Then on the bathroom groups, bring the 3" line across to a sanitary tee over the stack or under the WC above, jogging the stack above or below the san-tee, respectively.

Cheers, Wayne

Did a fast sketch, I am on track with you I believe, can try to get you plan for joist and rafter stuff but I only have a couple usable walls because of triple and double joist on top of walls I do have the two lavs backvented and an open space up top to tie it all into and tie into that vtr that does go straight up, but is pointless down in the basement I could just tie all vent in up top, it’s really just in the way down their now if my sketch is close to what your thinking. And switch the stack over to 3” right after clean out.

 

[wwhitney]

The last drawing looks fine, except I don't understand the horizontal blue line between the lav and tub drains. The only vents needed for the bathroom groups are the two lavs. Then the shower and the tub have to join their respective lav drains within the maximum trap arm length, 8' for 2" and 6' for 1-1/2", if you have perfect 1/4" per foot slope.

Cheers, Wayne

 

[OddsAndEnds]

The last drawing looks fine, except I don't understand the horizontal blue line between the lav and tub drains. The only vents needed for the bathroom groups are the two lavs. Then the shower and the tub have to join their respective lav drains within the maximum trap arm length, 8' for 2" and 6' for 1-1/2", if you have perfect 1/4" per foot slope.

Cheers, Wayne

That blue one is the vtr that like I said is pointless and runs from their horizontal back to where second floor goes up in that 2x6 tub wall and straight up through and was intended to backvent into but it serves no purpose running all the way into basement when I can tie my vents in up top without it being all the way in basement, and is now seriously just in the way of tying things together. Almost want to just take it out and reframe the 2x6 tub wall it runs through. Stack isn’t glued so I have room their.

 

[wwhitney]

A horizontal dry vent takeoff is prohibited. Remove it.

Cheers, Wayne

 

[OddsAndEnds]

Already did, and I can get it all the way out up above and since I have nothing glued yet I might just reframe 2x6 tub wall it ran through and put back in 2nd floor stack, and it gives me the space I need for my connections. Finding it’s easier to run kitchen 2nd fl in the back and baths in the front lines things up better with wcs ,on the first wc on left can I do a wye and dump it straight into 3” clean out on the backside and come in horizontal with my lav wet vent.

 

[OddsAndEnds]

A horizontal dry vent takeoff is prohibited. Remove it.

Cheers, Wayne

So I re-worked stack a little, brought the kitchen and washer over and tied it into second fl and took to stack. Re-worked first floor bath groups down sized line to 3” and got wc above stack tied in. Got rid of that ridiculous vtr line, and now have the room to bring my branches in on a regular wet vent. Put the bath group line in front because it makes it a little easier for rest of connections, plus it lined up wcs better, got some pitch stuff to work out but think I should be good for the most part. Thank you for the feed back and your guidance input and suggestions, truly a huge help and very appreciated.

 

[OddsAndEnds]

So I re-worked stack a little, brought the kitchen and washer over and tied it into second fl and took to stack. Re-worked first floor bath groups down sized line to 3” and got wc above stack tied in. Got rid of that ridiculous vtr line, and now have the room to bring my branches in on a regular wet vent. Put the bath group line in front because it makes it a little easier for rest of connections, plus it lined up wcs better, got some pitch stuff to work out but think I should be good for the most part. Thank you for the feed back and your guidance input and suggestions, truly a huge help and very appreciated.

So did a partial dry fit, changed stack a little and the big question is the horizontal wet vents, the best I can get my connections coming into the the back horizontal with my branches is less than 45 I know it’s supposed to be horizontal to horizontal but it’s the best I can do without dropping out of joist, as is my traps are going to be a little low, thoughts? Will it work as is s as and is my layout close? Any feedback snd critique would be greatly welcomed and hopefully I am on the right track, thank you everybody in advance for t as t as taking the time to look.