Venting HELP!!!

[Jonny V]

I'm praying someone qualifed can help me out with this venting question (TERRY!!!!). I'm adding a shower to a half bathroom in my one story house and need to know what size vent pipe I need to support the fixtures. Right now I have installed a 3" vent pipe that goes through the roof and is connected directly to the main sewer stack in the basement. The toilet is directly on top of the stack with the 3" vent connected via a Y just below the toilet (which I assume is technically a wet vent, maybe???). Connected to the 3" vent in the attic is a 1.5" vent that serves a basement washing machine and laundry sink. The additional fixtures that need to be added and vented are the shower and 1 bathroom sink. My plan was to connect the the 1.5" vents from the shower and sink together with a sanitary T and then keep going to the 3" vent that goes through the roof. However, is the 3" vent sufficient to serve a washing machine, laundry sink, shower, toilet, and bathroom sink? Or do I have to isolate the sink, shower, or both and run one or more new vents through the roof? Thanks! I'm in NJ by the way.

 

[Sylvan]

3" should be fine

 

[Sponsor]

 

[Reach4]

My plan was to connect the the 1.5" vents from the shower and sink together with a sanitary T

Tees and wyes used for vents go upside down from the way they would be oriented for drainage. In reality its not a big deal, but some might think it is important. So just invert.

 

[Jonny V]

Tees and wyes used for vents go upside down from the way they would be oriented for drainage. In reality its not a big deal, but some might think it is important. So just invert.

I drew quickly but I will make note. What do you think about the 3"? Is it to code? And sufficient for that many fixtures?

 

[S. Hillman]

Johnny,
The vent stack is based on the drainage fixture units (DFU's) for a bathroom group 1, a washing machine, and a laundry sink. Added together, they are well below what 3 inches of venting will handle. I don't have my code book in front of me for the actual numbers, but I'm quite sure 3" will be fine.

 

[Reach4]

3 inch is fine, as Sylvan said. I don't know NSPC code, so I don't know if the shower and sink venting are OK with the toilet upstream of them. I presume the shower and sink are not vented before they hit the 3 inch.

Bring the toilet in below those, and everybody would like it.

 

[Jonny V]

3 inch is fine, as Sylvan said. I don't know NSPC code, so I don't know if the shower and sink venting are OK with the toilet upstream of them.

Bring the toilet in below those, and everybody would like it.

Wish I could but the toilet is located literally directly on top of the main stack. It's the same in my other bathroom as well. House is from 1950s, so I guess that's how they did it back then? Everything was cast iron but I ripped it all out and replaced with PVC, at least until the the cast goes under the concrete basement floor. Maybe when I get around to finishing the basement and putting a bath down there I'll feel ambitious and cut open the concrete floor and rid myself of cast iron all together!!!

 

[Reach4]

You could vent the sink and shower before they join that stack.
If that is a bathroom sink, you could vent just that, and then join the shower drain in the right way before it joins the toilet waste.

And I am not sure if it would be OK in NJ as you drew it, but I suspect not. I am not a plumber.

I am confident that it would work great as you drew it.

 

[Jonny V]

You could vent the sink and shower before they join that stack.
If that is a bathroom sink, you could vent just that, and then join the shower drain in the right way before it joins the toilet waste.

And I am not sure if it would be OK in NJ as you drew it, but I suspect not. I am not a plumber.

I am confident that it would work great as you drew it.

Lost me a bit here.

If you mean I could vent the sink and shower separately through the roof, yes, I could definitely do that. But the less holes in the roof the better IMO.

Not sure what you mean by joining the shower drain before the toilet. As I noted the toilet waste is directly on top of the main stack so maybe I'm missing it but I cant see a way to join the stack before the toilet. I would have to create like a C shape with the toilet waste line to get it to come into the stack below the sink. Doesnt seem reasonable to me. But hey I'm no plumber

 

[Reach4]

If you mean I could vent the sink and shower separately through the roof, yes, I could definitely doing that.

No. I mean with a pipe branched off like the several you drew. In fact, I now see that is what you had in mind. I failed to read the labels before. So what you drew will be very good. Everybody and every code will like it.

 

[Terry]

3" easily does the bathroom, in fact a 2" vent would handle the bathroom.
3" handles the entire home which the bathroom is a part of. Normally when I'm plumbing homes with the UPC code, I'm using several vents which make up a 3" area. That would often be two 2" vents and a single 1.5" vent, which combined equals a single 3".

 

[Terry]

Two bathrooms vented with a 2".

 

[Jonny V]

3" easily does the bathroom, in fact a 2" vent would handle the bathroom.
3" handles the entire home which the bathroom is a part of. Normally when I'm plumbing homes with the UPC code, I'm using several vents which make up a 3" area. That would often be two 2" vents and a single 1.5" vent, which combined equals a single 3".

Ok so I'm good with the size and design for the 3 piece bathroom washing machine and laundry sink?

Follow up is a two part question.

1. When venting the shower can I use a sanitee right after the P-Trap to turn the vent backwards in the opposite direction of the drain pipe then go up the wall to the attic? The horizontal run of that vent would be about 15" before it turned vertical into the wall. Is this allowed?

2. Does the 1.5" vent port of that sanitee need to be twisted above the 2" waste line? Or can I lay it horizontally with the waste line? I only have 2x8 joists so the P trap barely fits within the depth of the floor joists. If I have to turn the vent up the P trap will surely hang down below the ceiling, which I would like to avoid.

Below is a mock up of what I would like to use.

Here is option 2 I thought of. This allows vent pipe to be vertical but I have to make a 180 degree turn with the waste line in the same floor joist bay, which includes a 4" round hvac duct.

 

[Jonny V]

Bump for additional questions

 

[Reach4]

For that floor drain venting, most people don't approve of a santee for carrying horizontal waste. A combo would be better there. Whatever you use there, it would be turned the other way.

No good way to avoid that 180? You could go farther (5 ft UPC 8 ft IPC NJ ?) without venting if that would help you reach a wall.

There are drains with a plug in the side of the bowl for rodding out without having to go thru the trap.

 

[Jonny V]

For that floor drain venting, most people don't approve of a santee for carrying horizontal waste. A combo would be better there. Whatever you use there, it would be turned the other way.

No good way to avoid that 180? You could go farther (5 ft UPC 8 ft IPC NJ ?) without venting if that would help you reach a wall.

There are drains with a plug in the side of the bowl for rodding out without having to go thru the trap.

I'm pretty sure the first picture I posted is totally wrong. That 1.5" coming out the side is supposed to be a vent line which I now think is totally wrong.

This is for a shower by the way. So the only real option I think is the second photo. The 180 would be at about a 45 degree down so I guess that's better but still not ideal I assume.

1. Is this allowable?
2. How many times is this going to clog on me?
3. Do I have to install a clean out even if the 180 is on a 45 degree down?
4. If so would the clean out be required before or after the 180? Before or after the vent?

Unfortunately that direction is the nearest main and that's really the only wall I can use for the shower vent. I'm battling HVAC which cant be relocated anywhere.

I have about 5 ft to the stack then another 2ft to the exterior wall where I can put a vent. So I dont think that helps me unless I can drain it without a vent?