Kitchen plus laundry branch layout help requested

[VikkiP]

Hello. I'm trying to help the kids with some improvements to their new-to-them 150 year old house with century-old infrastructure.

The kitchen sink has a rollercoaster of 1 1/2" (a collection of 90s and 45s feed an s trap) which is not vented, then runs 10' horizontally to a vertical stack in the basement. The vertical stack is not vented, the top of the stack terminates in a plug. The septic tank is just a few feet away and is vented outdoors. The washing machine drain hose was running directly into a short standpipe, no vent. The washing machine is to the left of the stack, the kitchen to the right and a floor above. The low heel had a direct trapless connection to the sump pump.

My thought is to build the stack as so: In the basement, left of the stack: 2" laundry standpipe 22" into 2" trap, horizontal 2" to vertical 3" via sanitary tee less than 8' away. Do I need an AAV on this run or a vent back to the 3" vertical?

For draining the kitchen above, my thought is to connect the 1 1/2" drain and trap into a trap adapter in a sanitary tee, with an AAV on the 2" outlet and 2" pipe heading down into the cellar. But my dilemma is finding the best way to tie into the vertical. Wye and 45 at each end? Sanitary tee and a low slope (but what fitting would I use to tie in the horizontal run to the vertical run?) Provision for a cleanout on the end of the horizontal run would be desirable.

Fortunately, the bath group is on another branch that connects outdoors, so anything I do is on an isolated branch.

 

[wwhitney]

1) Yes If you choose to revent to the 3" stack, you will need to vent the 3" stack with an AAV or by extending it through the roof, and your laundry standpipe vent will need to connect to the 3" stack at least 6" above the flood rim level of all fixtures that drain to the stack on any story.

2) Kitchen sink tailpiece -- 1-1/2" tubular trap -- 1-1/2" trap adapter -- 1-1/2"x2"x1-1/2" san-tee with barrel vertical -- 1-1/2" AAV on the top entry of the san-tee at least 4" above the trap arm -- 2" drain goes to the vicinity of the stack however you like--turn to 45 degrees below horizontal -- 3x3x2 wye cut into the stack (barrel vertical).

Cheers, Wayne

 

[Sponsor]

 

[VikkiP]

1) Yes If you choose to revent to the 3" stack, you will need to vent the 3" stack with an AAV or by extending it through the roof, and your laundry standpipe vent will need to connect to the 3" stack at least 6" above the flood rim level of all fixtures that drain to the stack on any story.

2) Kitchen sink tailpiece -- 1-1/2" tubular trap -- 1-1/2" trap adapter -- 1-1/2"x2"x1-1/2" san-tee with barrel vertical -- 1-1/2" AAV on the top entry of the san-tee at least 4" above the trap arm -- 2" drain goes to the vicinity of the stack however you like--turn to 45 degrees below horizontal -- 3x3x2 wye cut into the stack (barrel vertical).

Cheers, Wayne

Thank you. I wish I had photos. The existing 3" stack is approximately 2' high - just enough to come out of the wall and support a series of bends and adapters to reduce to 1 1/2" for the kitchen sink. There's no getting above the flood rim of the sink above on the stack for the kitchen sink. I've sketched 2 potential vent layouts for laundry, and I'm not sure how to transition to vertical at the kitchen.

 

[wwhitney]

Ah, a stack is a vertical drain or vent that extends at least one story. Sounds like you just have a short vertical drain section. So stick with AAVs, one for the washer standpipe, and one for the kitchen sink.

I'm not following your question about routing the kitchen sink drain. Are you saying that the part I listed as '2" drain goes to the vicinity of the stack however you like--turn to 45 degrees below horizontal' is unclear to you? The usual rules for running drains apply. If you want to turn the drainage from plumb (true vertical) to horizontal (2% slope), use a LT 90.

Cheers, Wayne

 

[VikkiP]

Thank you. I wish I had photos. The existing 3" stack is approximately 2' high - just enough to come out of the wall and support a series of bends and adapters to reduce to 1 1/2" for the kitchen sink. There's no getting above the flood rim of the sink above on the stack for the kitchen sink. I've sketched 2 potential vent layouts for laundry, and I'm not sure how to transition to vertical at the kitc

Hello. I'm trying to help the kids with some improvements to their new-to-them 150 year old house with century-old infrastructure.

The kitchen sink has a rollercoaster of 1 1/2" (a collection of 90s and 45s feed an s trap) which is not vented, then runs 10' horizontally to a vertical stack in the basement. The vertical stack is not vented, the top of the stack terminates in a plug. The septic tank is just a few feet away and is vented outdoors. The washing machine drain hose was running directly into a short standpipe, no vent. The washing machine is to the left of the stack, the kitchen to the right and a floor above. The low heel had a direct trapless connection to the sump pump.

My thought is to build the stack as so: In the basement, left of the stack: 2" laundry standpipe 22" into 2" trap, horizontal 2" to vertical 3" via sanitary tee less than 8' away. Do I need an AAV on this run or a vent back to the 3" vertical?

For draining the kitchen above, my thought is to connect the 1 1/2" drain and trap into a trap adapter in a sanitary tee, with an AAV on the 2" outlet and 2" pipe heading down into the cellar. But my dilemma is finding the best way to tie into the vertical. Wye and 45 at each end? Sanitary tee and a low slope (but what fitting would I use to tie in the horizontal run to the vertical run?) Provision for a cleanout on the end of the horizontal run would be desirable.

Fortunately, the bath group is on another branch that connects outdoors, so anything I do is on an isolated branch.

A photo

 

[wwhitney]

So if you on the floor above you add an AAV for the kitchen sink, and you move the standpipe to the right to allow room between the san-tee and the trap to add an AAV on its trap arm, the existing kitchen sink drain routing is fine, assuming that elbow in the upper right of the photo is a LT90. The standpipe needs to be at least 18" in length.

Cheers ,Wayne

 

[VikkiP]

So if you on the floor above you add an AAV for the kitchen sink, and you move the standpipe to the right to allow room between the san-tee and the trap to add an AAV on its trap arm, the existing kitchen sink drain routing is fine, assuming that elbow in the upper right of the photo is a LT90. The standpipe needs to be at least 18" in length.

Cheers ,Wayne

Thank you. So I should cut the laundry trap arm and use a san-tee on its back to give a vertical dry vent riser for the AAV? And then I can replicate the kitchen drain underfloor in 2" with long sweep 90s on both ends and come into the top of the vertical vent as the old 1 1/2" was? I'm fairly comfortable with the undersink layouts, but I've generally contracted out the drain layouts. Thank you very much for the guidance.

If I wanted to add a cleanout to the end of the kitchen sink run in the basement, what's the best combination and orientation of fittings to do that?

 

[Reach4]

If I wanted to add a cleanout to the end of the kitchen sink run in the basement, what's the best combination and orientation of fittings to do that?

The most likely place for a clog is where the flow goes from vertical to horizontal. That turn should be a long sweep or 2 45s. My first thought was to put a combo (combination of a wye and a 45) where that bend is now. Let the extra port be a cleanout, but that only lets you go one way.

Putting the long sweep there with a 2-way cleanout on the horizontal run would let you run the snake both ways.

A cleanout above or below the santee of the kitchen sink would be good.

 

[wwhitney]

Putting the long sweep there with a 2-way cleanout on the horizontal run would let you run the snake both ways.

That would be unwise and probably disallowed, as the 2-way cleanout doesn't direct drainage from vertical to the downstream horizontal. I.e. it's a drainage fitting only for the straight through path.

Cheers, Wayne

 

[Reach4]

That would be unwise and probably disallowed, as the 2-way cleanout doesn't direct drainage from vertical to the downstream horizontal. I.e. it's a drainage fitting only for the straight through path.

Cheers, Wayne

I was picturing the 2-way cleanout would be on the straight horizontal path to the left of the new long sweep 90. By being downstream of the suspected clog point, it might cause less spillage than if it were on the vertical.

 

[wwhitney]

I was picturing the 2-way cleanout would be on the straight horizontal path to the left of the new long sweep 90. By being downstream of the suspected clog point, it might cause less spillage than if it were on the vertical.

Ah, I thought you were suggesting the 2-way cleanout instead of the combo or LT90. A 2-way cleanout on the horizontal after the LT90 would be hard to access given the height of the horizontal. I think the combo is the conventional solution.

Cheers, Wayne

 

[Reach4]

Combo would be nice for flow, and thus makes a clog less likely, but if the cleanout is to the right, then you could not rod upward.