NSPC (NJ) Horizontal vent under basement slab legal?

[mrordinary]

I am unable to easily bring vents vertical in the location of an existing bathroom.

In the picture you can see a 2" vent that runs above a 3" sewer line. Both lines run 15 ft to the basement wall in which the vent goes up to the roof.
Is this horizontal venting allowed?

Two pictures are shown. The one with the Original shows that the vent line goes past the shower wye. Supposedly this was supposed to vent both fixtures. However, I read somewhere, I believe IPC, that the toilet has to be the final fixture downstream. Does anyone know if this is true for NSPC and can cite it?

The 20230212 picture shows a few proposed changes:
1. I am raising the shower horizontal arm so that it will be above the center line of the 3" sewer line so if there is a backup, waste will not flow into the shower drain.

2. In red I am proposing attaching the vent to the shower arm and right after the toilet.

For clarity I have also added the last 2 pictures so you can see where the horizontal run starts from.

Any thoughts on either scenario?

Thanks!

Attachments​

 

[Tuttles Revenge]

If horizontal wet venting is allowed then the system looks fine, as long as NJ doesn't require the toilet to be the most downstream fixture as the UPC does. Otherwise the sinks dry vent takes care of all of those bathroom fixtures.

 

[Sponsor]

 

[Lightningwill]

I could be wrong, but I think that shower should be vented separately from the main line so that a slug of water from the toilet can't siphon it when that water is between the shower arm and the vent takeoff.

NSPC does not describe this situation precisely. It shows a lav wet venting a bathroom group, but in this case, it doesn't look like your sink has a venting mechanism of its own.

 

[mrordinary]

The sink will have its own aav.

 

[mrordinary]

If horizontal wet venting is allowed then the system looks fine, as long as NJ doesn't require the toilet to be the most downstream fixture as the UPC does. Otherwise the sinks dry vent takes care of all of those bathroofixtures.

I couldn't find anything that said the toilet had to be last. Not sure why NSPC wouldn't say that if there is a potential issue of siphoning

 

[Jeff H Young]

You have a photo showing arrows of a vent for shower and vent for toilet connecting under slab ? what are those 2 underground serving at the far side ? I dont think fixtures outside of bathroom or fixtures from another floor can run through wet vents either.

 

[mrordinary]

You have a photo showing arrows of a vent for shower and vent for toilet connecting under slab ? what are those 2 underground serving at the far side ? I dont think fixtures outside of bathroom or fixtures from another floor can run through wet vents either.

Here is a blueprint of what it looks like. I believe you are also asking about the other line intersecting at the bottom left of the picture? If so that is an underground waste line from the kitchen sink that has its own vent elsewhere on the roof.

 

[Jeff H Young]

what about the other one that says "vent" underground I cant see any thing draining into it and it cant be a vent for the shower rolled up

 

[mrordinary]

what about the other one that says "vent" underground I cant see any thing draining into it and it cant be a vent for the shower rolled up

The vent is rolled over right after the shower on the 3" main line. It then makes a bend toward the left so that it can go to the wall and go vertical with the 3" sewer pipe.

There is only one wet vent which is attached by after the shower drain (the orange line shows the full path). An Aav will be attached to the sink.

what about the other one that says "vent" underground I cant see any thing draining into it and it cant be a vent for the shower rolled up

 

[Jeff H Young]

I dont see anything as wet vent Ive asked but that pipe that sys vent dosent appear to be picking up drainage upstream ? maybe there says somethging off the page appears to be some sort of note at the very top of page. but as it is looks illegal to me

 

[mrordinary]

I dont see anything as wet vent Ive asked but that pipe that sys vent dosent appear to be picking up drainage upstream ? maybe there says somethging off the page appears to be some sort of note at the very top of page. but as it is looks illegal to me

I will start from the top of the page. The label there says vent and it goes up to the roof (2 stories). Right beside it is a 3" stack that is carrying the waste from a full bathroom which is completely vented also to the roof.

Both come down and enter beneath the concrete slab. The 3" sewer is 6 inches below the 2" vent. Both of them follow the 1/4" slope required.

The 3" sewer pipe has a sink tapped into it which will have an AAV. Right after a toilet connection is made, and finally a shower is connected.

The 2" line parallels all these fixtures and about a foot where the shower enters the 3" line, the vent that comes from the roof attaches to the 3" sewer pipe, it is rolled at an angle to keep it above the sewer line.

So there is a vent from the roof that is downstream from the shower, and an AAV at the sink. I called the 2" vent a wet vent, but perhaps that was in error. It goes directly to the roof.

 

[Jeff H Young]

Yea the vent is dry wont fly. the 3 inch line going over there is illegaly venting the toilet as well. so a couple major issues

 

[mrordinary]

Yea the vent is dry wont fly. the 3 inch line going over there is illegaly venting the toilet as well. so a couple major issues

How would you fix this situation? I figured the toilet would be wet vented through the pipe and then pickup the dry vent the same as the shower.

 

[Jeff H Young]

It would have to be rebuilt so the upstair waste joins down stream of the bathroom . branch with toilet would be wyed into with a 2 inch to pick up the lav and shower. it would eliminat running the vent over into the next room as well as the lav will be the vent for all 3 fixtures. I see no need or legal way to have the vent come up where you have it.

 

[Alex Michal]

As of my last knowledge update in January 2022, the specific legal regulations regarding horizontal venting under a basement slab in accordance with the New Jersey State Plumbing Code (NSPC) may have been subject to updates or changes. However, I can provide some general information.

In plumbing and construction, adherence to codes and regulations is crucial for safety and compliance. Venting systems are typically regulated by plumbing codes, and specific requirements may vary by location. It's recommended to consult the latest version of the New Jersey State Plumbing Code or contact the local building department or plumbing authority in New Jersey for the most accurate and up-to-date information.

When dealing with questions about the legality of a particular plumbing installation, it's advisable to seek guidance from a licensed plumbing professional or consult directly with the local building department. They can provide insights into the specific code requirements, permits, and regulations applicable to your situation.

If your inquiry is specific to a recent or proposed change in regulations after January 2022, I recommend checking the latest version of the New Jersey State Plumbing Code or contacting relevant local authorities for the most current information.

 

[Jeff H Young]

As of my last knowledge update in January 2022, the specific legal regulations regarding horizontal venting under a basement slab in accordance with the New Jersey State Plumbing Code (NSPC) may have been subject to updates or changes. However, I can provide some general information.

In plumbing and construction, adherence to codes and regulations is crucial for safety and compliance. Venting systems are typically regulated by plumbing codes, and specific requirements may vary by location. It's recommended to consult the latest version of the New Jersey State Plumbing Code or contact the local building department or plumbing authority in New Jersey for the most accurate and up-to-date information.

When dealing with questions about the legality of a particular plumbing installation, it's advisable to seek guidance from a licensed plumbing professional or consult directly with the local building department. They can provide insights into the specific code requirements, permits, and regulations applicable to your situation.

If your inquiry is specific to a recent or proposed change in regulations after January 2022, I recommend checking the latest version of the New Jersey State Plumbing Code or contacting relevant local authorities for the most current information.

I would expect it was finished a year sgo