I Need to Vent

[Thomas K]

Can any of you guys tell me how to fix this two-sink vanity drain mess? I paid a plumber to do this, and it's all wrong.

There is a 2" vent going through the roof in the smaller bathroom back-to-back with this one that I could tap into, but the only other accessible drain I could use is a 2" stub-out (photo) directly beneath the PVC drain pipe shown in photos. That stub out is currently connected to the original shower and sink drains in smaller bathroom, so if I used it, it would have three fixtures on it: a two-sink vanity, a 36" shower, and a small sink.

If I really need to cut into that 4" cast iron stack to fix this, I probably need to replace it with PVC.

Thanks for any replies!

-Thomas

 

[Reach4]

Want an easier way? Take a look at the Rectorseal 97402 Magic Trap with the Rectorseal 97400 AAV. You would need two -- one for each sink.

https://rectorseal.com/product/magic-trap/

Now how about the shower? What is there would work great, but I doubt that it meets current IPC code. I could easily be wrong on that. I am not a plumber. https://wabo.memberclicks.net/assets/pdfs/Plumbing_Venting_Brochure_2018.pdf

 

[Sponsor]

 

[wwhitney]

The tee for the left-hand vanity is the wrong fitting, it should be a combo.

You could add a dry vent takeoff between the two vanities with a vertical combo, and then run that vent up and over to connect up with the existing vent in the adjoining bathroom. The left hand vanity would be wet vented by the right-hand vanity.

Or instead of a dry vent, you use could an AAV like Reach4 suggested. It would only need to be on one of the two vanities, I believe, as that vanity would wet vent the other.

Cheers, Wayne

 

[Reach4]

Do you think the shower would be considered "stack vented"?

 

[wwhitney]

Perhaps I misunderstand the OP, but my interpretation is that the "original shower and sink drains in smaller bathroom" are already vented by the "vent going through the roof in the smaller bathroom."

Cheers, Wayne

 

[Thomas K]

Perhaps I misunderstand the OP, but my interpretation is that the "original shower and sink drains in smaller bathroom" are already vented by the "vent going through the roof in the smaller bathroom."

Cheers, Wayne

I will draw a schematic of the way the smaller bathroom is currently plumbed, as well as a diagram of what I am proposing to do and post them on here a little later as uploaded files. Inspector I've been talking to suggests I pull a permit and have a local inspector tell me how my piping needs to be constructed, but sometimes it takes weeks for one to even come out.

I tried to download a couple of schematics, but website says they are too big, and I don't know how to make them smaller on my computer.

 

[Thomas K]

Do you think the shower would be considered "stack vented"?

Yes.

 

[Thomas K]

Here are my latest drawings, done this afternoon. I am not a plumber; I can do the work and have experience assembling PVC lines, but I am not current on the exact plumbing pieces and layout needed. I hope the proposed drawing explains what I'm trying to do. I paid one plumber $1000 to do the piping for vanity and bathtub, and drains were all wrong. Roto Rooter told me I could use the current vanity drain setup, but with an AAV added to the end of the pipe and extending into the attic. They also told me the tub didn't need a vent because the overflow acted as a vent, which I also know is wrong. I'm not trying to slam somebody here, but I do want to do it right.

 

[James Henry]

Whoever did that is not a real plumber, the tee for the middle lavatory is a fitting for water pipe not drainage pipe, and as mentioned already the 90 on the end needs to be a sweep. it will fail inspection in a heart beat.

 

[Thomas K]

Drawings can be seen in link posted further down.

 

[James Henry]

I tried to upload a drawing of what I wanted to do to fix it, but website says drawing is too large to upload, and I don't know how to make it smaller on my computer.

you could draw it in " windows paint".

 

[Thomas K]

you could draw it in " windows paint".

Photos can be seen here:
https://www.diychatroom.com/threads/i-need-to-vent.704277/post-6323500

Maybe I should pull permits, even though the entire bathroom is gutted, and what would an inspector say when he sees all of that? I've been working on this for a year off and on; and wife and I still can't get moved in.

 

[wwhitney]

I looked at your drawings in the other thread (it would be better to upload them here for consistency).

Everything you've proposed downstream of where the 4" horizontal upstairs drain turns downward looks OK to me (assuming fittings of the proper sweep, e.g. any "tee" in the drains should be a combo tee-wye). And the existing configuration upstream of that point looks OK if you had only a single vanity with the trap within 6' of the 'current 1-1/2" stub to vanity' (a sanitary tee). As far as I can tell, the shower and two toilets are properly wet vented in the existing configuration.

Looking more closely at IPC Section 911 at https://up.codes/viewer/alabama/ipc-2015/chapter/9/vents#911 I think the basic idea of the layout in the photo in the OP is actually OK as an IPC common vent if the longer trap arm meets the 6' limit on length. You'd just need to change the fittings to have the proper sweep--the tee needs to be a tee-wye, and the 90 at the far end needs to be a long sweep 90 (not sure what's there now).

However, I'm not so familiar with IPC Section 911, so it would be helpful if someone else agreed that it covers the situation shown in the OP.

Cheers, Wayne

 

[Thomas K]

I tried to upload photos here, Wayne, but website said they were too large to upload. I think I understand what you mean by using the tee-wyes because they direct the flow of water back toward the 4" cast iron. I am installing a dual-sink vanity, which is why I was thinking of capping that 1.5" stub in the earlier pictures and adding new plumbing like in the second drawing, with the dual vanity vented by a pipe plumbed into the existing 2" vent in the roof, and instead of draining into that 1.5" stub, drain pipe would drop through floor and join 2" stub lower on drainpipe, a picture of which I have posted here.

To recap: Presently, the 2nd floor bathroom is plumbed only as shown in the drawing on other website labeled "current." Second drawing depicts work I haven't done yet. I am trying to work out exactly how to finish plumbing everything before doing any more to avoid problems. I am planning on leaving most of the cast iron intact, including toilet pipes, which will be capped by PVC and hub connectors. It is the dual vanity (in main bathroom) and plumbing of smaller bathroom which is back-to-back with main bathroom that is giving me problems. I want to install a new 36" shower in smaller bathroom eventually, removing all of the cast iron in it up to the stub in photo included here. It is those fittings I am trying to make sure are correct. The present iron shower trap hangs low in the ceiling of first floor, and if I replace it with PVC and vent it from the 2" vent instead of 4" cast iron stack I can mount it higher and have higher ceiling.

Currently, in small bathroom, 2" pipe in roof vents only the sink in small bathroom. I wanted to expand that 2" pipe to vent that sink, new 36" shower, and dual-sink vanity in main bathroom. All 2" pipes going into that stub on cast iron shown in pictures below will be drain pipes only. Stackable washer and dryer are going in main bathroom, behind a wall. I want to put a small sink on first floor, where a washer was already plumbed, only whoever installed the pipe didn't vent it. So I would have to tap a fourth line off of the upstairs 2" roof vent and run down to first floor sink, or use an AAV on it.

I think, since I am asking for help here, that I need to draw out each section (eg. two sink vanity plumbing, small bathroom plumbing, etc.) and ask for scrutiny before proceeding with another, to avoid confusion.

For my diagram to work, it will have to be okay for three 2" pipes to drain into that single 2" stub in photo below. The shower, small bathroom sink, and dual-sink vanity. Shower and small sink already go there; I just wanted to replumb with pvc. I will also have to have 3-4 1 1/2" vent pipes tied to a single 2" vent pipe exiting roof. Maybe 4 pipes if I can run one pipe down to first floor sink. If this will work, I will make drawings of what I think the fittings should be to each fixture, and maybe, if I ask kindly, people will be good enough to point out my mistakes.

Thanks!

-Thomas

 

[Jeff H Young]

I dont know about alabama code but its horrible out here. And Thomas you were asking about permits . every where Ive been permits are required for such work , a year and a half in and now you might get one , I suppose something to think about .
Sorry I jumped around a bit but If you arent capable you really need to find someone that is. You got all the walls open its a very easy job for a real pulmber no reason to do a bad job. My only guess is you cant find a plumber . hire only a lic plumbing contractor or master however they do it there

 

[Thomas K]

I'd rather do the work myself. I know I probably should use a plumber, but we already gave up over a thousand dollars and got nowhere, which depleted our savings. I can do the work, and have experience with pvc. I'm just not experienced enough to know how to do the layout. I meant working on weekends as far as time goes. I work 50-55 hours a week as a mechanic (33 years) already and don't have much free time, so I work on the house when I can.

 

[wwhitney]

Currently, in small bathroom, 2" pipe in roof vents only the sink in small bathroom.

So, that 2" pipe dry vents the sink. But it also wet vents the current shower. Your proposed diagram includes several additional dry vents, which is fine, but it is work that you can avoid by maintaining the wet venting.

Cheers, Wayne

 

[Thomas K]

I could maintain the wet venting, but that means I would have to keep the shower trap where it is, low in the ceiling, and would have to keep all the cast iron plumbing in smaller bathroom as it is, because the trap cannot be higher than its vent. Sure, I could install new pvc, but it would be just as low. If I dry vent new pvc trap I can raise the trap about a foot.

I'd still have to replace the cast iron with pvc in order to be able to add a drain for two-sink vanity, wouldn't I? To add a drain onto stub? Either that or cut into that 4" cast iron stack, which I don't want to do, to add a drain for vanity sinks. And then there's the question of whether a new shower base drain would line up with the old cast iron drainpipe.

I just keep kicking myself.

 

[Breplum]

I have to agree with Jeff H Young's comment about hiring a competent licensed professional.
I also relate to your financial need to cut costs.
The only way to make the lav drains to UPC: Cut the cast iron tee out.
Lower a new 4 x 2 tee either run a 2" line horiz and vert up at a middle point between sinks to a figure five (2 x 1-1/2 x 1-1/2 x 1-1/2 ) and either figure a way to vent over to your existing tie back in higher up on the 4".
If there are other bathrooms in the house, you do not need a 4" vent. UPC says cumulative vent area must equal the area of the larges required drain, which is often 3".
You will absolutely/likely have to cut out the shower drain to put a new pan in.

 

[Jeff H Young]

Thomas Just want to let you know Ive never heard of anyone pulling a permit to get advice on how to do the job thats pretty unconventional . Another thing cutting the cast iron aint that big a deal its all opened up . Id likely cut the stack put a tee low and replace that pvc to the two lavs . Id bee done with that with out the proper tool to cut the cast in an afternoon. I gotta go back through all these posts but this sounds like an empty house that you just tinker with here and there? Since your a mechanic I suppose DIY might work I was assuming you werent too handy with tools guess you been working on other stuff besides the plumbing when you pull permit they expect you to make progress , or they cancel permit at least threaten to make you pay again