Basement Bathroom rough-in: please check my design

[Reach4]

I asked my plumber about using the ejector pit's vent through roof (VTR), but he was adamant that code required that vent to serve only the pit and nothing else. I still want to verify that.

I find nothing in section 906.5 that says the vent needs to be dedicated to the pit.
https://codes.iccsafe.org/content/IPC2018/chapter-9-vents
Also see section 908.8.

But anyway, I see no IPC objection to sealed septic sumps having their vent through roof (VTR) join other vents above 6 inches above the highest fixture being vented from that point.

For venting with no interior wall, trap arms are often run to the wall to hit the vent, and then the direction changes to direct the waste to where it needs to go.

IPC allows sanitary tees "on their back" for venting, although combos and 45s would of course be good too.

If it were up to me, trap arms separately entering the vented pit high enough (above water) would not have to have their own vents. Obviously it is not up to me, and you do have to vent fixtures before entering the pit.

 

[Zayd]

Thanks for taking a look at the code. I read it the same way. Perhaps it's time to push my plumber a little harder on it and ask him to produce the code reference that supports his position. If I can indeed use the pit vent, I can lose an extra couple inches of ceiling height in the bathroom to bring the lav vent up and over, connecting with the shower vent at the ceiling. Then I can run down an open joist bay straight to the pit vent.

 

[Sponsor]

 

[Dar Dack]

As Reach4 mentioned above, the dry vent has to enter the drain line at no lower than 45 degrees from vertical. That means my drain lines need to be deep enough to accommodate that higher entry, then at least a 45-degree turn towards the closest wall, then maintain slope until it gets there, and still stay under the slab. That puts my drain lines way down and likely too deep to maintain 1/4" per foot for 20' to my basin.

Oh I'm sorry I didn't realize your plumber was 100% dry, so he doesn't want to wet vent because there's no way to fix if problem, but even if you use AAV's stuff still under concrete without ability to fix if something happens. IDK, i'm sure there are plenty of wet vent under concrete without issue. (also just thought about, won't shower be wet vent regardless, even with AAV, at least a couple feet?)

But let's say 20' away, you need what a 3" pipe for toilet, that's 3.5", a WYE set on a 45 angle with a 2" outlet for vent is probably 1.5" above the 3.5", take that straight back to a wall, and looks like you are adding 6" on top of the basin, so your entry is going to be even farther down than 10", so shouldn't you have plenty of room?

 

[Dar Dack]

Thanks for taking a look at the code. I read it the same way. Perhaps it's time to push my plumber a little harder on it and ask him to produce the code reference that supports his position. If I can indeed use the pit vent, I can lose an extra couple inches of ceiling height in the bathroom to bring the lav vent up and over, connecting with the shower vent at the ceiling. Then I can run down an open joist bay straight to the pit vent.

Yeah for mine it was just the GPM and length of 2" pipe for vent. Only pneumatic require dedicated according to code that my inspector was aware of. You could call your local building inspector and ask. That's what I do. That way you know 100% what will pass or not.

 

[Zayd]

Oh I'm sorry I didn't realize your plumber was 100% dry, so he doesn't want to wet vent because there's no way to fix if problem, but even if you use AAV's stuff still under concrete without ability to fix if something happens. IDK, i'm sure there are plenty of wet vent under concrete without issue. (also just thought about, won't shower be wet vent regardless, even with AAV, at least a couple feet?)

But let's say 20' away, you need what a 3" pipe for toilet, that's 3.5", a WYE set on a 45 angle with a 2" outlet for vent is probably 1.5" above the 3.5", take that straight back to a wall, and looks like you are adding 6" on top of the basin, so your entry is going to be even farther down than 10", so shouldn't you have plenty of room?

He doesn't mind AAVs, but he's not a fan of the lav AAV venting the whole bathroom.

When I measured out the height gain of the vent wye/san-tee, it put me lower than the 10" inlet of the basin -- of course that was before I discovered I could lower/extend the basin. At this point, I want to work with the trenches I have. I mentioned above that I still can dry vent the lav and shower if I can indeed share the vent. I just messaged my plumber to poke him on that. He's an eccentric fellow, so we'll see how he responds...

 

[Dar Dack]

Well good luck either way.

 

[Zayd]

Well, a long, hard day, but the deed is done. This picture doesn’t reflect the last bit of progress, which was chiseling out the shower area about 1.5” lower to accommodate a curbless shower.

View attachment 81051

I was browsing this old thread (was on hold for summer projects, so I'm back at it now) and realized I didn't post the final pic with the shower area chiseled out. @wwhitney you can see that I took your advice in most places to break off at the kerf rather than cut all the way through.

 

[Zayd]

An update from me and a question.

I've placed the ejector pit and dug my trenches down a sufficient amount for my rough plumbing. I've started laying out and gluing pipe and fittings, but I've hit a snag on the specs for my Geberit Duofix carrier. The installation instructions are not clear on the 3" pipe location relative to the front edge of my 2x6 wall framing. This is how Geberit describes it in their instructions:

The "Stud Front to Center Pipe" at the bottom of the right drawing shows 3 1/2" to 5 3/16". Am I to assume that the 3.5" applies to 2x6 framing, while the 5 3/16" applies to 2x8 framing? If it's 3.5" to center, that leaves me just under 1/2" to the back of the 2x6 framing, which is fine. The backside of the carrier is a storage room and won't have drywall up anyway.

I'd expect the rough plumbing requirements to be crystal clear, but this is not helpful... or I'm reading it wrong. I'd appreciate confirmation on it.

 

[Zayd]

An update from me and a question.

I've placed the ejector pit and dug my trenches down a sufficient amount for my rough plumbing. I've started laying out and gluing pipe and fittings, but I've hit a snag on the specs for my Geberit Duofix carrier. The installation instructions are not clear on the 3" pipe location relative to the front edge of my 2x6 wall framing. This is how Geberit describes it in their instructions:

View attachment 89254



The "Stud Front to Center Pipe" at the bottom of the right drawing shows 3 1/2" to 5 3/16". Am I to assume that the 3.5" applies to 2x6 framing, while the 5 3/16" applies to 2x8 framing? If it's 3.5" to center, that leaves me just under 1/2" to the back of the 2x6 framing, which is fine. The backside of the carrier is a storage room and won't have drywall up anyway.

I'd expect the rough plumbing requirements to be crystal clear, but this is not helpful... or I'm reading it wrong. I'd appreciate confirmation on it.

I spoke to Geberit and got a little insight into this. The short of it is that if you angle the soil pipe up to 45 degrees from vertical, this would probably require the discharge to land behind one of the legs of the frame. This, in turn, would require you to push the rough-in pipe further back.

The installation manual doesn't communicate that, but it makes sense. So it's 3.5" for me.

 

[Reach4]

It sounds to me as if that output can telescope in or out a bit, with a range of about 2.36 inch. Is that what you are understanding?

 

[Zayd]

It sounds to me as if that output can telescope in or out a bit, with a range of about 2.36 inch. Is that what you are understanding?

That is correct -- there is adjustment in the fore/aft placement of that elbow. So I assume that the 3.5" rough-in is with the elbow all the way forward.

 

[Zayd]

Update:

The township inspector came by today to inspect the rough plumbing. He was a very friendly gentleman and was clearly trying to work with me and not be a pain. He complemented me on my clean work (woohoo) and had three points of feedback:

1. After reading here about running the ejector pit vent out and up the exterior wall and through the roof overhang, I offered that as my plan. He said that it had to be protected from the weather because water vapor in the pipe would freeze in progressively smaller concentric rings and clog the vent. This was new to me, but I didn’t press him on it. So now I’ll be opening up some walls upstairs to run a new line to the attic. I’ll probably just run two while I’m at it and get rid of the AAVs altogether.

2. He hadn’t inspected rough plumbing for a wall-hung toilet before and asked me to contact the manufacturer about how the toilet gets vented. He must have investigated further after he left, because he called me soon after he left to tell me I’m all set on the venting.

3. He wanted a cleanout for the toilet branch. We looked at the Geberit elbow that comes with their carrier and couldn’t figure out exactly how to pull that off, given that the elbow sits so close to the ground that there’s no room for a cleanout fitting between it and the ground. I plan to contact Geberit to see what they recommend, but I’m all ears here as well.

I’m attaching pictures of my overall rough plumbing and the toilet branch in particular.

 

[wwhitney]

On (3), zero experience here, but if the backside of the wall is going to be a reasonable place for a cleanout to stick out of the ground, you could replace the closet bend with a wye plus a 45. The 45 would go below the wye, and the cleanout would be on the straight path on the 45, with the branch inlet pointing straight up for the wall hung WC.

Cheers, Wayne

 

[Reach4]

2. He hadn’t inspected rough plumbing for a wall-hung toilet before and asked me to contact the manufacturer about how the toilet gets vented. He must have investigated further after he left, because he called me soon after he left to tell me I’m all set on the venting.

If you joint a vented lavatory or vented shower to the toilet waste before non-bathroom waste joined the toilet waste, the toilet would probably be properly wet vented. And he probably recognized that.

 

[wwhitney]

2. He hadn’t inspected rough plumbing for a wall-hung toilet before and asked me to contact the manufacturer about how the toilet gets vented.

More to the point, the factory elbow that comes with a wall hung WC is the equivalent to an internal portion of the trap way on a floor outlet WC. So that factory elbow has to be vertical for the WC to work (maybe up to 45 degrees is OK), and then starting at the bottom of that elbow, it's just like a regular WC as far as venting.

Cheers, Wayne

 

[Zayd]

On (3), zero experience here, but if the backside of the wall is going to be a reasonable place for a cleanout to stick out of the ground, you could replace the closet bend with a wye plus a 45. The 45 would go below the wye, and the cleanout would be on the straight path on the 45, with the branch inlet pointing straight up for the wall hung WC.

Cheers, Wayne

Makes sense. The area directly behind the toilet will indeed be a storage room, so it's an ideal spot for the clean-out. It would require a little more concrete removal but nothing excessive.

I'll first confirm that there will indeed not be enough room for a traditional cleanup directly above the current long-sweep elbow and below the wall-hung elbow.

 

[Tuttles Revenge]

A wye in the horizontal drain, downstream of the toilet, that pokes up next to the toilet or another side wall would be easiest but would want to avoid the framing for the carrier and leave enough concrete to hold the carrier feet and wall anchors.. You absolutely want the carrier and wall framing to be Solid. We recently fixed one where the framing and carrier were all loosey goosey.

Looking at a 3" cast iron cleanout tee which is the most compact, they are 7" end to end, which is the same height of the center of the drain to the floor when the carrier is set to its highest setting... so that would be problematic to try to squeeze that in the vertical between the elbow

 

[Zayd]

Looking at a 3" cast iron cleanout tee which is the most compact, they are 7" end to end, which is the same height of the center of the drain to the floor when the carrier is set to its highest setting... so that would be problematic to try to squeeze that in the vertical between the elbow

After some staring and measuring and thinking, I realized I have an excess of pitch on the toilet run, so I can gain about 1.5” of height at the stub. Given that the finished floor will also be about 1.75” above the slab, I think I may have enough room to squeeze a cleanout fitting in there. My question: does it matter what type of fitting I use as a cleanout? I have a couple of options. I’d like a sanitary tee so that the sweep let’s anything that hits that side find its way down, but it’s about an inch longer than a cleanout tee. A straight cleanout tee will save me about 1” of distance hub-to-hub, but I’m not sure if it’s practical given all the stuff that will be coming down that pipe. It seems to me like I’d run the risk of “debris” sitting on that ledge. Is that a reasonable fear?

 

[Tuttles Revenge]

A san tee will stick further out of the wall once you glue in an insert clean out body. But you can get a Street San tee to fit into the long sweep. I couldn't find any Street cleanout tees in plastic.. only cast iron.

If you're opening up the clean out, no matter what fitting, you're already resigned to the fact that its a poop pipe and the reason for opening it is to insert a cable to touch the poopie..

 

[Reach4]

After some staring and measuring and thinking, I realized I have an excess of pitch on the toilet run, so I can gain about 1.5” of height at the stub. Given that the finished floor will also be about 1.75” above the slab, I think I may have enough room to squeeze a cleanout fitting in there. My question: does it matter what type of fitting I use as a cleanout? I have a couple of options. I’d like a sanitary tee so that the sweep let’s anything that hits that side find its way down, but it’s about an inch longer than a cleanout tee. A straight cleanout tee will save me about 1” of distance hub-to-hub, but I’m not sure if it’s practical given all the stuff that will be coming down that pipe. It seems to me like I’d run the risk of “debris” sitting on that ledge. Is that a reasonable fear?

You are looking to put the cleanout with the flow horizontally under the floor with the cleanout plug above? Or are you thinking of the flow being horizontal thru a wall, and the cleanout plug would be on the side, and accessed thru the wall?

Were you wanting the cleanout plug flush with the surface, or would you be looking to have a removable piece of floor/wall that would give access to the deeper cleanout plug?