Vent advice needed for far away tub

Users who are viewing this thread

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
Hi all - first time poster here. My husband and I renno old historic homes in our spare time and i'm the plumber of the family - I consider myself a 'master DIYer'. I've done probably 10-15 baths, but I'm stumped on this one. It's probably a super easy fix, but I've thought about it too much and can't ponder it anymore. So ... Help!

Planning out the DWV for our new master bath. I am NOT an artist, but I hope you can see what you need. There is currently one 2" vent thru the roof (Vent A) and I'm running another up to the attic (Vent B). This could go thru the roof, or just run across attic and connect into A.

My problem is with the whirlpool tub. There will be a 2" trap and it's more than 8 feet to either vent. And, it's on corner exterior walls, both brick/plaster, so can't have its own vertical. There are two options for drain, but both are over 8. Drain option B would be just a few inches over 8' to the vent, by the time I angle the trap ... inspector might let it slide. But, there is so many connections going on at the 3" pipe there, I'd rather connect in to shower drain, Option A.

How do I vent this thing? Do I run a slightly pitched vent alongside the drain under the floor to the main vent B?

Thanks in advance for your expert help!!
Steph
 

Attachments

  • master_bath_plumbing.jpg
    master_bath_plumbing.jpg
    37.7 KB · Views: 961

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
No guidance for me? Can anyone help?

I made a new diagram. Just a tiny bit better. Still not 3-D, but maybe clearer.

I also have a new question, also about distance. I am reading code about trap arm (for 2" drain) not being longer than 8'. Both the tub and shower are about 9ish feet to the drain ... Am I understanding that code correctly?

So again, how do I vent this tub?
Thank you!
 

Attachments

  • MasterBathPlumbing.pdf
    149.8 KB · Views: 480
Last edited:

Cacher_Chick

Test, Don't Guess!
Messages
5,458
Reaction score
213
Points
63
Location
Land of Cheese
The vent must rise vertically from the trap arm within that distance.
You route the drain so that the vent can go up into a wall. Sometimes it means boxing in a place to run the pipe, or building a intermediate stud wall inside the existing exterior wall to contain the piping. You can also build a low section of wall (like a shelf) where the vent can rise vertically inside to at least 42" before it permitted to run horizontally to an alternate wall for it to go up throgh the roof. With some thought and creativity, you can make it look like it is a functional part of the room design.
 
Last edited:

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
Thanks for the reply. Ya, that was my last resort. I was hoping to do something under the floor, rather than boxing in anything. I hate boxes that are soley meant to hide things.

I thought I read somewhere about branching the vent from the drain, close to the trap, then running it horizontally under the floor, but at a gradual upwards slope, for the 9 feet till it reaches the wall. But now I can't find where I read that. Is that a possibility?

Also, about the drain and trap arm length of 8' max. Is that only in regards to venting? So, as long as I vent within the 8', I can run horizontally as long as I want? Or is there still an 8' max trap arm.
 

Reach4

Well-Known Member
Messages
38,797
Reaction score
4,412
Points
113
Location
IL
A 3 inch trap arm could extend the allowed distance. The distance allowed varies with code. IPC allows 12 feet with 3 inch. VA has its own code, so it probably differs, and is probably less permissive. I think you would need 3 inch drain pipe after it.

After it is vented, I think it is no longer considered to be part of the trap arm. I am not a pro.
 

Cacher_Chick

Test, Don't Guess!
Messages
5,458
Reaction score
213
Points
63
Location
Land of Cheese
The horizontal drain can go to Texas if you can figure out how to maintain 1/4" per foot pitch the entire way.
 

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
OK, thanks. That's what i always thought, but something I was reading y'day (while trying to figure out a non-boxed-in-vent), led me to believe otherwise. Anyone in Texas want to drain my bathroom :)
 

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
OK, got an idea to rid the need for boxing in a vent pipe. I always put the trap directly at the fixture drain, but I understand it doesn't HAVE to go exactly there. If I do a long sweep 90 under the drain, then put the trap 6" downstream, I can reach the vent pipe in just under 8 feet. I don't like not having the trap right at the fixture, but this is a tub that will rarely get used, so thinking we shouldn't have a problem with gunk. Sound OK?

Only remaining issue is how to get the shower to vent without having a dry horizontal vent under the floor. Thinking to just run the drain to the North wall before turning East. That adds an extra 90 into the drain, but allows me to vent directly up the North wall.

Uploaded a jpg this time. Look OK?
 

Attachments

  • Screen Shot 2016-02-05 at 9.47.31 AM.png
    Screen Shot 2016-02-05 at 9.47.31 AM.png
    66.3 KB · Views: 945

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
ok, they say a picture is worth 1000 words. Attached is my current toilet drain and where i'd like to add the shower drain and vent

I marked where I wanted to bring the shower line in. I wanted to get the 90 turn and a vent in 1 fitting, but can't quite find a fitting to do that.

Also, If I add this vent for the shower, I don't that that vents the toilet, since it's behind the drain?? I think not. But, I've also read that a vent is not required for the toilet.

Please advise!
 

Attachments

  • IMG_3672[1].JPG
    IMG_3672[1].JPG
    118.4 KB · Views: 822

Cacher_Chick

Test, Don't Guess!
Messages
5,458
Reaction score
213
Points
63
Location
Land of Cheese
I cannot see what is preventing the shower drain from being ran to the north wall and running the vent up there. It will require a cleanout, which can be accessible from the wall.
 

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
Yep, that is what i'm doing, running the shower to north wall. Thinking that if I do a 45 turn to the main drain, I don't need a cleanout?

For the tub, there was just no way to vent without build a box. I realized I can do a AAV, 4 inches above the drain, accessible from the removable tub skirt. (I originally thought it needed to be 6' above highest fixture, but I realize now that's only for stack AAV).

Can someone comment on the toilet vent. In my photo, there is a proposed vent to the right (upstream) of the toilet drain. Does that vent the toilet?
 

Cacher_Chick

Test, Don't Guess!
Messages
5,458
Reaction score
213
Points
63
Location
Land of Cheese
If the 3" "main stack" is going through the roof with no fixtures draining into it from above, it is the vent for the toilet.
 

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
no, that stack does not go thru the roof, it just bends into the toilet there.

Edited to add, This stack is serving only this master bathroom, plus the kitchen below it. (Kitchen sinks will likely be vented with AAVs). There are (at least) 2 other vent stacks in the house, going thru the roof. Each is 4 inch.

So, still the question. Is this configuration of vent to toilet OK for the master bath?
 
Last edited:

Cacher_Chick

Test, Don't Guess!
Messages
5,458
Reaction score
213
Points
63
Location
Land of Cheese
It do not see a proper vent for the toilet, so I am not sure where you think there might be one. If you don't want to bring the 3" through the roof, keep it going up in 2" and tie it into one of the other vents in the attic.
 

StephK

Member
Messages
40
Reaction score
2
Points
8
Location
Richmond, Virginia
Thanks cacher_chick. Ya, the 3-inch stack cant's continue straight up b/c there is a chimney there in the way. What if I add a 2-inch vertical to that side inlet on the toilet 90. (Where the big yellow arrow is, in the pic). It would go up to the attic and turn across the room to meet the outside vent on the north wall.

I think that would work for the toilet vent, yes?
 

Attachments

  • IMG_3672[1].JPG
    IMG_3672[1].JPG
    122.3 KB · Views: 837

Cacher_Chick

Test, Don't Guess!
Messages
5,458
Reaction score
213
Points
63
Location
Land of Cheese
Any inlet on a closet bend is strictly prohibited here where I am, so you will have to refer to your local code.
I am for sure that a vent take-off must be vertical, so coming out the side should not be considered.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks