WA state - ski lodge waste design

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MattSkiWA

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I have read enough of the plumbing code to guess how deep the rabbit hole goes and I'm up to my eyeballs. In pre-COVID days, I'd take my DIY plans down the local AHJ, ask questions, get feedback, and then go apply pipe cement. This week I called Terry, and he suggested I post here.

This bathroom is in an old ski lodge in King county Washington. The lodge has a building trap. During the winter season, the lodge is only heated on the weekends and the water is drained at the end of each weekend and a little antifreeze is poured into each trap. Existing plumbing is all ABS so we're sticking with that, in 4" and 2" sizes. The waste trunk is 4" to the toilets and 2" to everything else. The main vent stack is 4" ABS and there's a second 2" vent that serves only a kitchen hand washing sink. I intend to replace that sink vent with an AAV. The following drains drop through the bathrooms new concrete floor: 5 toilets, 1 waterless urinal, and 3 sinks. The floor itself is concrete sloped to 4 floor drains. There are two additional sink drains coming down from the kitchen immediately above the bathrooms. They drop through the bathroom inside the two strategically placed partition walls. The hand washing sink in the kitchen is the obligatory 1 DFU fixture plumbed in front of the waterless urinal.

Here's a layout of the bathroom:

2022 Stevens Bath.jpg


The upper right corner is a combined shower, and urinal stall. The lower right corner is the accessible / family / caregiver stall, with a toilet, sink, and shower. Both rooms are waterproof so there's no shower surround (think: wet room). The entire bath room can be cleaned with a can of scrubbing bubbles and a garden hose. The showers are rarely used in ski season and the shower stalls will get some use as changing areas. In the fall, a smaller number of hikers use the lodge and the showers are used heavily.

Here is my plumbing layout:

2022-08 Stevens Waste.jpeg


The bottom and right are rough sawn 2x6 exterior walls, which will have snow against them for the duration of the winter. The walls are a bit under sized for the building height and snow load so there will be no hole drilling in the exterior walls. Along the bottom wall is the string of 5 toilets. The drain slopes toward the front of the building (top of the drawing) with the cleanout on the lower right edge (after string of lavs) being the highest point.

Inside the horizontal partition wall is a 2" drain from the AAV vented kitchen sink island and a 4" vent popping out the side of the building and ascending the outside wall. Inside the vertical partition wall is a 2" drain from the kitchen handwashing sink. It comes down inside that wall, runs across to the urinal, and then drops through the floor.

My questions:

Can I use a circuit vent (as shown, see also "circuit venting" below) for the string of toilets?

Can the circuit vent be 2 inch as shown in the IPC definition?

Can the leftmost lav be considered part of the circuit vent?

Upslope of the 5 toilets, a floor drain enters, then the circuit vent, and finally an AAV vented sink. The floor drain is within 6' of the circuit vent. Can it be vented by that circuit vent?

Thoughts, questions, and concerns? My twin goals are for this to work reliably for 50 years and to pass inspections without any rework.

Thanks in advance,
Matt

circuit-vent.jpg
 
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Tuttles Revenge

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In short, yes. Curcuit venting would handle that entire building.

Here is the King County Horizontal and Curcuit Venting rules with examples drawn.

I've never installed it per se and I can't work on a diagram right now, but its certainly doable.

All the connections need to meet the Horizontal trunk in the horizontal and 2" is your minimum venting required.

circuit-vent-example-7.jpg
 
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Jeff H Young

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Those underground flat vents on the floor drains look like an issue. Ive never done circuit venting but the vents I mentioned dont seem part of that but appear to be dry vents.
Circuit venting the water closets Ive only seen the circuit vents installed in a vertical position I dont know if its required but looks like thats actually a horizontal wet vent you got going on.
A little confused by your wording are you calling the toilets , Lavs? I dont mean to be critical but I had to keep looking back and forth but am convinced you must have mixed up the terms.
Id look over those issues with the flat vents and the circuit vent rules. good luck on it Matt you should get some helpful feed back here.
 

Tuttles Revenge

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This is my interpretation of circuit venting.. having never installing it.

stevens-mountainier-13.jpg


Circuit venting.png
 
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MattSkiWA

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@Tuttles Revenge, great reference, and tips about meeting in the horizontal. I had questions about circuit vents that the document answered, including "The most upstream fixture should not be a fixture that is seldom used, such as a floor drain." In this case, the floor drains at the end of the circuit are also shower drain, so can they be the most upstream fixture?

In your sketch, the waterless urinal has no fixture upstream. I'm pretty sure I read that is required, but perhaps that's not relevant here?

@Jeff H Young, the floor is over a crawl space, so the vents aren't flat. I did mix up the terms, sorry. I just corrected them.

stevens-mountainier-01.jpg


Toilets will be on the wall to the right.
Bathroom sinks on the left. In the far corner on the left, a shower stall.
It will be a coed bathroom like they have in Europe.
Picture and comment added by Terry Love

stevens-mountainier-14.jpg
 
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Tuttles Revenge

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@tuttle, great reference, and tips about meeting in the horizontal. I had questions about circuit vents that the document answered, including "The most upstream fixture should not be a fixture that is seldom used, such as a floor drain." In this case, the floor drains at the end of the circuit are also shower drain, so can they be the most upstream fixture?

In your sketch, the waterless urinal has no fixture upstream. I'm pretty sure I read that it is required to, but perhaps that's not relevant here?

@Jeff, the floor is over a crawl space, so the vents aren't flat. I did mix up the terms, sorry. I just corrected them.
You've likely read it more thoroughly than I have at this point. We just never use circuit venting. I have had a hard enough time getting everyone on board with horizontal wet venting. My sketch was based on my quick skim of the subject, so maybe some tweeks are needed.
 

John Gayewski

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Every 4 toilets need a relief vent so you can't put 5 toilets with two vents as I understand it.
 

MattSkiWA

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@John Gayewski, when using a horizontal wet vent or circuit vent (as shown), every toilet is considered vented. The top half of the horizontal pipe is the vent and up to 8 fixtures can be vented per circuit, per the UPC and the King County rules (see post above by @Tuttles Revenge).

@Tuttles Revenge, thanks again. Are you in King County by chance? I feel like I owe you at least a beer.

Attached is a revised layout based on @Tuttles marked up diagram, that takes into account a couple inconveniences.

1. In the 2018 Plumbing Code it says, "Where nonwater urinals are installed, not less than one water supplied fixture rated at not less than 1 water supply fixture unit (WSFU) shall be installed upstream on the same drain line to facilitate drain line flow and rinsing." I see only two options: the kitchen handwashing sink or the bathroom sinks located 8' to the left. The kitchen sink drain is located on the same side the chimney, making it a favored option.

2. Because the kitchen sink is on another level, and we need it to rinse the urinal drain, the sink / urinal line is not allowed to be circuit vented due to: 911.5 "Fixtures, other than the circuit-vented fixtures, are permitted to discharge to the horizontal branch drain. Such fixtures shall be located on the same floor as the circuit-vented fixtures and shall be either individually or common vented." To comply, I've individually vented the floor drain and urinal and I plan to use AAVs for the bathroom sinks.

3. The waste line coming in is inconveniently located so this version has two circuit vents for the toilets. The other option of putting all 5 toilets in line would require an extra 270° of turns to get it flowing in the right direction. That would also project further into the crawl space, which is used for storage.

2022-08 Stevens Waste.jpeg
 

MattSkiWA

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Look at those straight boards! They don't make 'em like that any more!

I've driven the road to Alpental many times but I haven't paid enough attention to the lodges there to know which one that one is. This plumbing plan is for the Mountaineers lodge at Stevens Pass.

stevens-mountainier-02.jpg
stevens-mountainier-03.jpg
 
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Terry

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Look at those straight boards! They don't make 'em like that any more!

I've driven the road to Alpental many times but I haven't paid enough attention to the lodges there to know which one that one is. This plumbing plan is for the Mountaineers lodge at Stevens Pass.
Steven's Pass, haven't been to that lodge. Our families ski passes are Stevens this year, and actually I'm driving Stevens tomorrow. Don't know what I was thinking.
The picture above were the army barracks at Snoqualmie West before they built the main ski lodge.

hyak-terrylove-06.jpg


Me skiing Hyak, 1958
 
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MattSkiWA

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I too will be driving to Stevens Pass tomorrow! :) Besides gathering more measurements, I need to inspect the mountain bike trails. ‍♂️ With a little coordination, I could arrange to have your favorite cold beverage on-site. Hint. Hint. The current used-beer facilities are named Fir, Pine, and Honey Bucket. Two-thirds of them are pine-fresh scented and have a great view.
 

John Gayewski

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Every 4 toilets need a relief vent so you can't put 5 toilets with two vents as I understand it.
See upc 911.4

I tried to reply to the above post my internet is being wacky.

I think when you have 4 toilets you need a relief vent as flushing 4 toilets at once will take up more space in the wet vent than can be left available for air.
 

MattSkiWA

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911.4 Relief Vent
A 2 inch (50 mm) relief vent shall be provided for circuit-vented horizontal branches receiving the discharge of four or more water closets and connecting to a drainage stack that receives the discharge of soil or waste from upper horizontal branches.

The relief vent is only required when both criteria apply. These circuit vents do not require a relief vent because they do not "connect to a drainage stack that receives the discharge of soil or waste from upper horizontal branches."
 

John Gayewski

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The relief vent is only required when both criteria apply. These circuit vents do not require a relief vent because they do not "connect to a drainage stack that receives the discharge of soil or waste from upper horizontal branches."
I just looked in an explanatory book or said the same thing. Lol
 

Tuttles Revenge

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I too will be driving to Stevens Pass tomorrow! :) Besides gathering more measurements, I need to inspect the mountain bike trails. ‍♂️ With a little coordination, I could arrange to have your favorite cold beverage on-site. Hint. Hint. The current used-beer facilities are named Fir, Pine, and Honey Bucket. Two-thirds of them are pine-fresh scented and have a great view.
If I didn't already have plans to hike with friends already.
 

Jeff H Young

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looks like the floor drain vents have been changed? It looked like they were tied together under floor
I may have misread something , hope its all worked out.
You guys have some beautiful country there. Hope one day to visit Promise not to stay LOL. besides work gotta have fun too!
 

Terry

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Matt showing me the water filters for the lodge.

stevens-mountainier-04.jpg


Our tour guide Penelope.

stevens-mountainier-05.jpg


I think this needs a p-trap.

stevens-mountainier-06.jpg


stevens-mountainier-07.jpg


stevens-mountainier-08.jpg


On the far wall is the 4" vent that also vents the downstairs bathroom.

stevens-mountainier-09.jpg


It seems this may need an indirect drain like we do for restaurants.

stevens-mountainier-10.jpg


Matt waving goodbye.

stevens-mountainier-11.jpg


Located at the Stevens Pass ski area, upper parking lot. In the Winter time, a walk up to the lodge, and then ski down to the lifts.
 
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