Venting Arrangement for Bathroom Remodel

[jeffesonm]

I am renovating a 1/2 bath into a 3/4 bath, adding a shower. I replaced my boiler last year so familiar with the supply side plumbing, but this is my first project involving waste/vent plumbing. I've done a bunch of reading and tried to design this all to code (NJ, it will be inspected) but I'm sure I overlooked some things.

The bathroom has been stripped to the studs and I have easy access to the attic above and 4' crawlspace below. There is an existing 3" copper vent line going through the roof above the bathroom that I would like to tie this all into.

Here is a pic of the overall layout of the bathroom It is only 5' x 6' so I am using a wall mount toilet and sink to save on space. The floor will slope to a liner drain against the back wall.

Overhead view of proposed venting layout. That is a little cluttered but hopefully will make sense after the next two.

Sink side layout.

P-trap beneath the sink, exposed. Then run into the wall and make a right and through one stud. Then drain drops down into crawlspace and vent runs up into attic, where it will be eventually tied to the shower/toilet vent and out the roof. 1 1/2" PVC for drain, and sanitary tee at drain/vent intersection.

Toilet/shower side layout.

Linear drain connects to 2" PVC drain line, then trap, then runs about 3' over to a sanitary T at drain/vent intersection. Wall mount toilet connects to 3" PVC stub via supplied hub (diagram above says 3.5", should be 3") PVC stub connects to long sweep wye with cleanout cap and runs a foot or two over and connects to drain/vent line below shower drain with sanitary tee. 3" waste line connects to existing cast iron line out to septic tank.

Up in the attic I will connect the two vertical vent pipes and then run them out the existing roof penetration. As mentioned it used to be 3" copper... can I just replace that with 3" PVC?

Does this look like a reasonable plan given the layout of the room? Any errors with respect to connections, pipe sizing, length, etc?

Thanks in advance... I would never be able to DIY projects like this without helpful experts sharing their knowledge.

 

[Cacher_Chick]

It will not be acceptable to have unvented fixture drains running to multiple sanitary tees on a stack, as only the top-most connected fixture is properly served by the vent stack. You can use a single sanitary tee with a side inlet, as this places both drain connections at the same level on the stack.

 

[Sponsor]

 

[jeffesonm]

I'm not sure that would work for me here, since the 3" sanitary tee accepting the toilet drain would have another 3" and I don't think I can reduce the pipe size to 2" for the vent. But very possible I am misunderstanding how it would be connected.

I feel like there has to be a simple way to vent all three of these on a 2" pipe but I am really struggling to figure it out. This thread seems to discuss this same thing but I am having a hard time making sense of it.

Also just general FYI I am in NJ so we are on the National Plumbing Code. Here is the section on went venting:

 

[jeffesonm]

Okay maybe I misunderstood what you were suggesting. Would I use a sani T with side inlet like this?

 

[MKS]

If the 3x3x3x2 pictured had the vent on the top, toilet from side, lav and shower from the side, lav and shower including the vent depicted via lav. Would that pass?

 

[jeffesonm]

After lots of reading and more coffee, I now understand why my sanitee+side inlet drawing above was incorrect. The vent needs to go up. Duh.

Okay let's try this again....

Version 2.... 3" drain from toilet has one bend and then connects to 3x3x2 low heel elbow, with 2" pointing up. 3" exits bottom of elbow and goes down to septic. 2" from low heel elbow goes up, turns, and runs to 2x2x2 wye?. Straight run continues straight to shower p-trap and branch of the 2x2x2 wye (which needs to be angled up) runs over to the sink wall and straight up and out the roof. 1 1/2" lav connects to this vertical pipe with sanitee(?)

 

[MKS]

I understand you are connecting to a vertical drain that then turns below grade.
The 3/4 bath diagram may apply.
This is upc.

 

[jeffesonm]

Thank you, I think I drew an uglier version of the same layout depicted in the 3/4 bath drawing above.

Do those connections sound okay? Low heel elbow pointing up, wye angled up and then sani tee at lav?

 

[MKS]

Proposals only.
Starting at lav.
2" vent with Santee for lav.
Drops into crawl space turns horizontal with a long turn/sweep 90.
Pointing towards toilet, pickup shower drain with a 2" combo/wye with 1/8 bend.
Make a turn for the existing vertical drain with a 3x3x2 combo/wye with 1/8 bend close unused end with clean out.
Connect toilet to 3 " line with a wye.
Use long turn/sweep 90 to turn down into existing drain line.
If the existing drain line is vertical and goes through the roof as a vent. I would use the above mentioned fittings and use the 3"3x3x2 you have pictured in an earlier post so the toilet and the lav/shower enter the drain at the same level, horizontal. I believe the way cacher-chic described.
Useful information.
Bert Polk plumbing tips.
Helpful Plumbing Hints for Residential Construction by Bert Polk Plumbing Inspector Lincoln County

 

[jeffesonm]

Thanks, I really appreciate the feedback. I will piece this all together and then post a pic before I actually cement things in place.

 

[jeffesonm]

I got this all plumbed together and put test plugs in the stubs and a balloon plug in the bottom cleanout. Filled it up to the roof and the inspector came by this afternoon to give the a-OK.

PVC went okay but much prefer working with copper... once you have it connected together correctly you can just sweat the pipes, rather than having to take it all apart again with PVC. Plus it looks nicer.

Thank for taking the time to help, especially you MKS. I would not have been able to do this without your input, and would not have been able to afford this bathroom renovation if I had to hire out the plumbing, electrical, etc. Financials aside I really enjoy learning new skills and understanding how everything works, and take pride knowing I did it myself.

 

[CountryBumkin]

Nothing more satisfying than doing it yourself, saving money, and having the job come out like a pro did it.

BTW - I see the cleanout fitting in your photo. How would one access this fitting once the floor is in place? Are you planning on having an access panel - or am I missing something obvious?

 

[MKS]

Glad it passed.