Venting a Utility Tub directly below Kitchen Sink

Users who are viewing this thread

DC907

New Member
Messages
2
Reaction score
0
Points
1
Location
Lebanon, Ohio
This is a request for advice prior to seeking a few local estimates. I would like to have a utility tub installed in the basement directly below the kitchen sink in our mechanical room. The kitchen sink waste line is 1 1/2" pvc fed into a 2" vertical PVC line with cleanout 24" above slab that goes under the slab into the main waste line. There are currently no other branches off the 2" PVC. I know that a vent pipe from the basement to the required height above the kitchen sink would require a major tear out and would not be worth the cost. The main vent stack is 30 feet away at the other end of the home. There is an accessible vent pipe (2" PVC) off the main stack serving a half bath in the basement, but the kitchen sink is vented independently (through the roof). I have read about air admittance valves and they are permitted in my county in Ohio and sold locally. My questions are below:

1. Could a solution be a 2" to 1 1/2" Wye on the kitchen waste line to serve the utility tub with an AAV accessible behind the tub's trap?

2. Could a solution be to vent the utility tub with a connection to the accessible vent line at the opposite end of the basement even though the kitchen sink is vented directly through the roof?

3. Am I better off scrapping the utility tub until such a time when a proper vent can be connected above the kitchen sink during a future kitchen rennovation?

Thank you for your advice.
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
I think #1 would work best, but you want to bring the AAV up on a stub from the trap arm. Really, the best solution would be to do an atmospheric vent, but as you said, that might require some significant tear out.
 

BruceL

New Member
Messages
20
Reaction score
0
Points
1
Location
Virginia
I wouldn't necessarily rule out tapping off the vent from the half bath. If you have a clear shot running 30' of DWV is a piece of cake. OTOH if there's ceiling in the way and you need to drill through joists, it could be a major endeavor.

However, I'm curious about the "accessible vent pipe (2" PVC) off the main stack serving a half bath in the basement." If it's a stack (i.e. there are drains attached to it above the basement) then as I understand it, it's a drain and not a vent and shouldn't be used as a vent. Which makes me wonder if someone before you put in the half bath and used a drain to vent it. Or is it a vent that taps off the main stack in the attic and comes down through the wall on the other side of the house?

Bruce
 

DC907

New Member
Messages
2
Reaction score
0
Points
1
Location
Lebanon, Ohio
I wouldn't necessarily rule out tapping off the vent from the half bath. If you have a clear shot running 30' of DWV is a piece of cake. OTOH if there's ceiling in the way and you need to drill through joists, it could be a major endeavor.

However, I'm curious about the "accessible vent pipe (2" PVC) off the main stack serving a half bath in the basement." If it's a stack (i.e. there are drains attached to it above the basement) then as I understand it, it's a drain and not a vent and shouldn't be used as a vent. Which makes me wonder if someone before you put in the half bath and used a drain to vent it. Or is it a vent that taps off the main stack in the attic and comes down through the wall on the other side of the house?

Bruce


The 2" vent is very accessible and can be easily tee'd and run the length of the house above a drop ceiling. Any crossing of joists that would have to be done could be done below the joists in the mechanical room (no drop ceiling). The half bath was roughed in when the house was built - there are no fixtures above this vent pipe. It is tied into the main stack above all fixtures in the attic. I know the purpose of the vent is air and pressure - am not sure the effect of such a long horizontal run for the vent before it drops down to the fixture. I am also unclear if it is proper to have two fixtures on two different floors using the same vertical waste line but also using two different vent sources. It all seems improper to me - but perhaps it is just not ideal?
 
Last edited:
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