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 Shower/Tub Venting
Author: jbimmerle (NY)

Hi All

First post in this forum although I have been a frequent visitor reading up on things as we go through a master and hall bath renovation. I've attached a picture of what the hall bath looks like fully gutted down to the studs to expose all the supply and drain lines (all copper).



I'll try to explain what is depicted in the photo. In the bay to the right of the recessed light can there is a three inch drain pipe that connects the master bath toilet (behind the back wall) and the hall bath toilet. The 3 inch vent stack rises up in the wall separating the two bathrooms and the master bath vanity drains into that stack (the horizontal run coming from the right).

To the left of the recessed light can there is drain piping that starts with a tub in the master bathroom (behind the back wall to the left). They increased the size of the drain run from 1.5" to 2" as the next fixture feeding into this run was the shower in the hall bath. The rest of the run is 2" which eventually drops into the main 3" line leading to the septic tank. The hall bath vanity (not shown) also drains into this 2" line. In between the master bathroom tub and shower the previous installer used a wye to start the 1.5" vent that runs horizontally about a foot or so before taking a 90 degree turn up. It then runs up another 4 feet before tying into the 3 inch vent stack shared by the two toilets and master bathroom vanity.

My question is whether or not this is correct/sufficient venting for the tub and shower? I hadn't noticed any draining issues aside those related to having to clean the drain of hair buildup (I have a wife and three daughters that have been using this bathroom so it's bound to clog up from time to time - :lol: ). I was just more curious if someone had any suggestions for improving the layout/runs to minimize any potential issues down the road. The plan is to replace all the run with PVC and see what I can get for all the copper (some of the runs have pin holes as I think it's starting to show its age from the 1975 install).

I've also included another shot of the vertical run of the shower/tub vent which also shows how the hall bath vanity vent currently ties in.



Thank you all in advance for any feedback/suggestions you can offer up.
Joe



Edited 5 times.

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 Re: Shower/Tub Venting
Author: packy (MA)

i can't open the picture..

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

Should be fixed now.



Edited 2 times.

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 Re: Shower/Tub Venting
Author: North Carolina Plumber (NC)

The vent in it's current configuration is a code violation. The horizontal run underneath the floor is dry, it needs to be washed with a fixture, or the vent needs to come up vertical downstream of the trap.

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 Thank you NC Plumber :grin:
Author: jbimmerle (NY)

Thank you NC Plumber for the response.

Would the best option be then to vent it via the hall bath vanity but make that vent a 2" vent as opposed to 1.5"? If not - do you have a suggestion on how best to remediate the code violation?



Edited 1 times.

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 Re: Shower/Tub Venting
Author: North Carolina Plumber (NC)

Does the hall bath vanity tie into the 2" downstream of the tub ? If so how far downstream of the tub trap ? It's possible that the dry portion of the tub vent could just be cut and capped off. Since you're only venting a sink and tub 1 1/2" is sufficient.

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 Re: Shower/Tub Venting
Author: packy (MA)

the shower is not vented properly.
you will need to move the 2 inch drain to the right where the rag is setting. run it straight back to the stud wall and put a 2 x 1 1/2 x 1 1/2 'Y' on its back with a 45 in the branch looking straight up the stud wall. come out of the back of the 'Y' and pick up the tub trap.
the shower is a problem as all second floor drain/vents are.
you will have to cut a 'Y' into the 2 inch to pick up the shower trap. but.. inbetween the 2 inch and the shower trap there has to be a vent. this is where it gets sticky. i suppose a 2 x 1 1/2 "Y" could be used but it will have to be a flat vent.

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 Thank you again for all the comments :thumb:
Author: jbimmerle (NY)

NC Plumber - The hall vanity does tie into the 2" line about 3.5 feet from the shower trap.

Packy - when you are referring to a flat vent - isn't that pretty much what is currently configured right after the tub trap with the wye laying on its side?

In general it seems like in the current configuration - the tub has a flat/dry vent that is not to code and the shower is not vented at all (at least that's my understanding) or not enough. So at a minimum I will need to insert another vent. How I accomplish that is still to be determined.

I think I'll try to sketch it out and post what I come up with back here for some comments as I'm having trouble fully visualizing it in my head.

Thank you again for all the comments so far. Really very much appreciated.



Edited 1 times.

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 Re: Shower/Tub Venting
Author: packy (MA)

please show a picture of the other vanity where it ties into the 2 inch.
it is entirely possible that the shower can tie into the vanity drain and be wet vented thru the vanity and its vent.

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

Here you go. The shower and tub drains are off to the right. To the left the 2" line ties into the main stack in my utility room (about 16 feet away).

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 Re: Shower/Tub Venting
Author: packy (MA)

if you can shift things around and get the shower drain into the branch of that 'Y' you'll be all set. you can go 6 feet from that new connection to the shower trap.
the shower will be wet vented thru the vanity drain/vent.
the 2 inch going left to right can then be reduced to 1 1/2 and pick up the tub while being vented up thru the stud wall.
piece of cake...

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

The shower does currently tie into that wye as the 2" drain coming from the right is coming from both the master bathroom tub and hall bath. So if I understand you correctly - the shower might actually be fine but the tub is now the remaining issue since it relies on a flat vent. To remedy that I should take your suggestion of bringing the line back and running it up through the stud wall and then tie the tub just upstream of that. Does that sound right?

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

After rereading your response Packy - I think I get what you're saying. I'll try and sketch it out and post back for comments. Thank you again for taking the time to respond.

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

Also just a quick (hopefully) separate question with regards to the two toilets using the 3" drain lines on the right (in the first photo). Is that acceptable? Seems like the toilet in the master bathroom would be fine but not sure about the one in the hall bath.

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

Ok - so here is a very rough sketch of what I was thinking would work based on the suggestions received so far. My apologies in advance for the poor handwriting and poor drawing ability - way too tired right now.

The key things to note between this diagram and the previous photos I posted are:

1) There are no longer two long horizontal runs down to the main stack as I was thinking of having the toilet run turn and go through the joists to pick up all the other drains and then turn once more and continue to the main stack. I understand that the goal would be to minimize turns but I've indicated that all would be long sweep fittings/turns while maintaining the appropriate slope (1/4" per foot). Part of the rationale for doing this is that the main cleanout for the main horizontal run to the septic (that receives the two runs shown in the first photo) is behind a wall with no access. I wanted to move the main run from these two bathrooms over to the farthest joist bay so that it would come out into my utility room with enough room to install a proper (and accessible) cleanout

2) The master bathroom tub is now vented separately going up through the stud bay as Packy had suggested. The horizontal drain run then connects into the 3" line running across the joists via a long sweep wye. The vent goes vertically into the attic and joins the 3" vent from the toilets. A wye + a 45 degree el is used to transition from horizontal to vertical. Note I've also chosen to bump the size of the drain pipe and vent up to 2" (probably not necessary but I sketched it this way)

3) The hall bath shower now drains into the same line as the vanity and shares the same vent (which goes vertically into the attic and then joins the 3" vent from the toilets). The shared drain line has been increased to 2" as well as the drain/vent for the vanity. The vanity sink trap will be 1.5" and use a sanitary tee with 2"x2"x1.5" layout. A wye + a 45 degree el is used to transition from the horizontal run to the vertical drain/vent



Thoughts?

Is the clean-out shown in the bottom left (where the 3" drain makes the final turn toward the main stack) required? If not - can I simply use a long-sweep 90 degree fitting as I used to start the run through the joists? I ask because it seems as if there are enough places along the runs to snake the drain if needed so not sure the clean-out is really adding any value. I would also need to install an access panel in the ceiling to make it accessible.



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 Re: Shower/Tub Venting
Author: packy (MA)

i think you've got it..
the cleanout is not required..
the tub drain and its vent can be 1 1/2 inch.
the wet vent for the shower can be run flat for the part under the floor. it will be washed by the draining vanity so it will not collect debris like a dry vent would. of course if it runs under a petition and you can have the vent go straight horizontal, all the better..
the 3 inch for the toilets is just fine..
so, all in all, you get a very high passing grade..
one last thought.. where you have the 3 inch long sweep 90's, you can use two 45's with a nipple in between.

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 Re: Shower/Tub Venting
Author: PlumberLoren (CA)

Since I don't know the scale of your drawing and size of your joists, I assume you have at least 2”x 8” Ceiling Joists that you are connecting these fixtures in, it seems like this system would be not code approved and flat and you will not obtain the amount of fall required, I am assuming. You mention daughter's and wife’s hair; that is always a problem at the tub, vanity lavatories and the shower. It will require continued maintenance to remove the hair as it slows down the drain process and the flushing you would need for this flat system. As I mention this is all speculation and I do not see any dimensions for the distances. If by chance both toilets were flushed at the same time you could siphon water from the trap of the hall bathroom toilet. If the Wye/Vent for that toilet isn’t rolled up which you cannot roll up enough if the joists are only 2x8. If you are drilling for the 3” waste, those 3 joists are really weak and would not pass inspection in my part of the woods (San Diego, CA) Or am I misreading the drawing and the waste is suspended below the joists in a basement or garage? You should have a 2 ½” cleanout in the hall bath for the toilets because your drains are so flat. Just thinking that If you could raise the floor level in the Master Bath 3” this would allow you to roll the wye to improve the wet vet situation. I don’t know the ceiling height of your bathrooms but you might consider this but don’t know if it is doable.

Post Reply

 Thanks Packy. Appreciate the feedback :grin:
Author: jbimmerle (NY)

Thanks Packy. Appreciate the feedback. Wouldn't the two 45s create more joints/fittings and potential for solid wastes to get trapped on the turn? Would they have roughly the same bend radius?



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 Thank you all again for the help :clap:
Author: jbimmerle (NY)

PlumberLoren

Thank you for the feedback as well. Sorry I didn't note the scale of things in any of my posts/drawings. And yes - I agree with you with regards to drilling too large a hole in the joists. I actually have 2x10 floor joists and we are planning to reinforce with something like the following (pending permit approvals):



So with these and the 2x10 depth - everything should work as I did some measurements from point to point to ensure that the slope worked along the way and that I wasn't drilling too low in each joist. Still this all has to be approved so while in my mind I think I have a halfway decent plan - the approving authority and inspectors here may think otherwise. Hopefully they can compromise with me in some regard but I've heard it's easier to beg for forgiveness than permission around here.

Thank you all again for the help. If there are any other thoughts please do chime in.



Edited 2 times.

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 Re: Shower/Tub Venting
Author: packy (MA)

around here they let us get away with glued and screwed plywood.
so you would cut pieces of 3/4 plywood 9 1/2 x 48. center them where the holes will be drilled. use construction adhesive and glue and screw (or nail) one on each side of the joist. then drill thru the entire 3 inch thick joist. it is not going anywhere. just don't put nails or screws where you are going to drill.
as for two 45's... with a 6 inch long nipple (3 inches between the hubs) there will be less restriction than even a long sweep 90.
lastly, no cleanout will be needed. even if you have 1/8 inch pitch, it won't clog.
if you did want to put a cleanout, put a cleanout tee in the vertical section of 3 inch stack. leave an access panel for it.

Post Reply

 Thank you all again for the help :)
Author: jbimmerle (NY)

Just curious - would OSB offer any additional benefits over regular plywood? I will suggest this as another option (or maybe the first since it's cheaper than the steel plates when we submit all the plans).

I see what you're saying with regards to the two 45s and short run in between. I'll see if I can get that to work but there may not be enough room to do that cleanly. Only way to really know will be to do some dry fitting.

Thank you all again for the help. This forum and it's members have been extremely helpful in working through some of these plans.



Edited 3 times.

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

With regards to the cleanout tee you mentioned - can I put that in the vertical section of the 3" stack that is in the attic (before it exits out the roof)? This way no access panel in the room would be needed and the attic is readily accessible via a ladder a few feet away.

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 Re: Shower/Tub Venting
Author: North Carolina Plumber (NC)

It would be unhandy to lug a 125 pound sewer cleaning machine up an access ladder to get to the cleanout tee.

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 Re: Shower/Tub Venting
Author: jbimmerle (NY)

Fair point - I hadn't considered having to haul any equipment up. I'll make sure to have it where it is more easily accessible. Thank you.

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 Re: Thank you all again for the help :clap:
Author: PlumberLoren (CA)

I think you are good to go providing you get blessings from Admin Authority.

Post Reply

 Re: Thank you all again for the help :cheers:
Author: jbimmerle (NY)

Yep - fingers crossed.

Thank you all again for the help.



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