DWV Rough in Question

[DJ O]

I am adding a new master bathroom to my house and wanted some feedback on my diagram before I start gluing the drain and vent pipes together. I ran a new 3" drain to my basement and I am going to tie that into the main sewer drain. Then upstairs it goes to a 3" San tee directly to a 3" 90 to travel horizontally against the wall. ( I have a LVL beam I cannot cut into and I have to make a soffit.). From there it will head to the WC and wye off to the shower and 1st lav and opposite will wye off and go to lav 2. I will be venting this with a 2" vent in the wall which will connect to the 1.5" vents from the lav. They will then come back to my main 3" vent stack. It all seems good to me, I just wasn't sure if the vent distances are within NJ NSPC. I would rather do it this way instead of making a new 2" vent through my roof only 7' away from the stack.

Once again all comments are welcome. Thank you all for your help. This forum is a wealth of knowledge and I have learned so much.

 

[Michael Young]

I am adding a new master bathroom to my house and wanted some feedback on my diagram before I start gluing the drain and vent pipes together. I ran a new 3" drain to my basement and I am going to tie that into the main sewer drain. Then upstairs it goes to a 3" San tee directly to a 3" 90 to travel horizontally against the wall. ( I have a LVL beam I cannot cut into and I have to make a soffit.). From there it will head to the WC and wye off to the shower and 1st lav and opposite will wye off and go to lav 2. I will be venting this with a 2" vent in the wall which will connect to the 1.5" vents from the lav. They will then come back to my main 3" vent stack. It all seems good to me, I just wasn't sure if the vent distances are within NJ NSPC. I would rather do it this way instead of making a new 2" vent through my roof only 7' away from the stack.

Once again all comments are welcome. Thank you all for your help. This forum is a wealth of knowledge and I have learned so much.View attachment 69587 View attachment 69584

everything is vented and you have a wet vent for your water closet. I'm not seeing a problem here. You don't need that extra relief vent. And you already have a whole house vent. So you could studor vent those fixtures if it makes your life easier.

 

[Sponsor]

 

[wwhitney]

AAVs in NJ appear to only be allowed in a system designed by an engineer (NSPC Appendix E.8).

The 3" vent can be deleted. Also the 2" vent for the shower can be deleted, if the trap arm from the shower drain to the point it combines with the lav drain is under 8'. Then one lav wet vents the shower, and the other lav wet vents the WC. [So probably worth rerouting the lav drain to join the shower drain earlier if the shower trap arm is currently over 8'.] You've already got the right size for wet venting for each lav drain starting at the lav san tee (2").

Cheers, Wayne

 

[DJ O]

AAVs in NJ appear to only be allowed in a system designed by an engineer (NSPC Appendix E.8).

The 3" vent can be deleted. Also the 2" vent for the shower can be deleted, if the trap arm from the shower drain to the point it combines with the lav drain is under 8'. Then one lav wet vents the shower, and the other lav wet vents the WC. [So probably worth rerouting the lav drain to join the shower drain earlier if the shower trap arm is currently over 8'.] You've already got the right size for wet venting for each lav drain starting at the lav san tee (2").

Cheers, Wayne

Thanks for the input. Wayne, Do I need to keep the lav vents at 2" or can i drop them down to 1.5". Also can I run these back to the 3" main vent that's about 14' away from where the lav vents will enter the attic. I would rather not have to open another hole in my roof.

 

[wwhitney]

Looks like NSPC follows the IPC's "1/2 the size of the drain pipe served" for vent sizing, so 1-1/2" vents would be OK. And yes, you can combine the vents in the attic.

Cheers, Wayne

 

[Lightningwill]

AAVs in NJ appear to only be allowed in a system designed by an engineer (NSPC Appendix E.8).

See the fall 2012 edition of the NJ Construction Code Communicator, page 7:

“Therefore, AAVs that comply with the standards listed in the ICC ES report are permitted to be used in one- or two-family dwellings and Class III structures without a design professional’s seal.”

 

[Reach4]

See the fall 2012 edition of the NJ Construction Code Communicator, page 7:

“Therefore, AAVs that comply with the standards listed in the ICC ES report are permitted to be used in one- or two-family dwellings and Class III structures without a design professional’s seal.”

I had read that. It could be clearer.

N.J.A.C 5:23-3.7, Municipal approvals of alternate materials, equipment, or methods of construction, requires the enforcing agency to approve materials, equipment, or methods of construction that are approved by ICC ES reports. Therefore, AAVs that comply with the standards listed in the ICC ES report are permitted to be used in one- or two-family dwellings and Class III structures without a design professional’s seal.​

Does that say that you would need an alternate materials approval, but that approval does not require a professional engineer to approve?

 

[Lightningwill]

I've read it more than a few times as well.

Given that the title of the section the quote is from is: “Air Admittance Valves are Allowed!!” (emphasis and quantity of exclamation marks theirs), I read it as the statute dictates, given ICC-ES approval, the plumbing subcode official must approve such items, thereby removing some of their normal ambiguous discretion to approve/disapprove of non-standard or uncommon things.