Any issue using this fitting?

[Pulse]

Presumably the vertical run is in the 2x8 wall or right next to it. Is that vertical run just one joist bay over from the current double wye?

The wall is the very next joist bay.

Are you looking to do the minimum rework necessary to get the double wye in for the toilet without making the headroom worse, or are you happy to redo all the drains below the floor to get more headroom? For example, I think you could wet vent both toilets and the shower via the lavatory, using a double wye on the horizontal rather than on the vertical.

Everything under slab is rearranged already, so making changes is fine. I do not want to make headroom worse.

And BTW, I see two toilets a shower and a lavatory, is there not a second lavatory associated with the second toilet? Or is it just drained separately?

Yes, it is on the other side, I already completely rearranged it. Here is an earlier drawing with labels:

OK, there's about a zillion possible placements and orientations of a double wye to get everything connected. Here's one option that I'm currently thinking is good. If it seems viable I can try to draw it up for you if it would help:

Yeah, just some basic lines over my current drawing would be great.

 

[Reach4]

Wet venting shower, and toilets. Blue is 3x3x2 santee.

For minimum height, can use Sanitary Tee, Street Reducing with street fitting on the bottom. Charlotte #404 3 x 3 x 2 seems hard to find in ABS. All-hub is easy to find.

Rename garage sink to garage bathroom lavatory.

 

[Sponsor]

 

[Pulse]

View attachment 66099
Wet venting shower, and toilets. Blue is 3x3x2 santee.

There is no need to wet vent the shower. It already has its own vent, removing it does not provide any advantage.

I had no idea if there will be room above or below the wye to do that(without dropping it down more which I do not want to do). A double wye is a lot larger compared to the existing san tee, especially so if i go 4".

Maybe something like this is best:

 

[Reach4]

There is no need to wet vent the shower. It already has its own vent, removing it does not provide any advantage.

It raises the path of the shower drainage so that it can more-easily come in above the double wye.

Your new picture doesn't do much to describe piping for me. It looks like it belongs in an art gallery, with other incomprehensible pictures. 90% just kidding.

 

[Pulse]

Your new picture doesn't do much to describe piping for me. It looks like it belongs in an art gallery, with other incomprehensible pictures. 90% just kidding.

yeah, sry, i didnt draw it and it got messed up when I opened it in my program.

Follow the red line. I am using two 45s to bring it to the side of the double wye, then into the 2x8 wall, 90 down, and finally into a wye and 45 off the main stack(inside the 2x8 wall)

 

[Reach4]

Follow the red line. I am using two 45s to bring it to the side of the double wye, then into the 2x8 wall, 90 down, and finally into a wye and 45 off the main stack(inside the 2x8 wall)

Is the shower the standpipe on the right of the new picture? If so, what you propose should work fine, but consumes more space below than needed.

You really don't like wet venting your shower.

 

[wwhitney]

Space is obviously tight between the upper 3" stack (currently with the double san-tee) and the lower stack (in the 2x8 wall). I'm happy to look up some dimensions in the Charlotte catalog to see what would fit, but I would need some dimensions to work with. So:

1) Which way is north (to simplify discussion)?
2) What's the distance perpendicular to the joists between the two stacks (one joist bay, so 12"-16")?
3) What's the distance parallel to the joists between the two stacks (I'm guessing 8" - 12")?
4) Is there a reason the offset in (3) has to occur outside the thickened plane of the 2x8 wall, rather than within?
5) What is the vertical distance from the bottom of the joists to the bottom of the white wrapped pipes? You may be able to get everything to fit in that region and increase your headroom.

Cheers, Wayne

 

[Jeff H Young]

Since I asume the picture with abs piping is your house . Why do all this work? changing to 4 inch yada yada? just use that double y and be done with it, the line is a bit low but close to wall. but removing the 3 x2 san tee will alow raising the horizontal 3 inch some with 45s . there are a few tricks to gain an inch or 2 more elevation if that is a big deal.
It looked pretty clean under there Is ther a bunch of old mickey mouse work your trying to correct moving stacks etc , that need doing? house dosent even look old.

 

[wwhitney]

OK, there's about a zillion possible placements and orientations of a double wye to get everything connected.

Here's a drawing of what I was describing. Line segments are pipes/fittings in the horizontal plane. Pipes going up or down are depicted as circles. I'm not sure it will fit, but I can check with the dimensions requested, plus one more:

(6) center to center distance on the toilets (12" rough-in, 2x6 wet wall, and 1/2" sheetrock would give 30-1/2")

Cheers, Wayne

 

[wwhitney]

OK, I took a look at the Charlotte catalog and laid it out in my simple CAD program. It seems everything would fit but it's borderline. So it's dependent on the exact dimensions requested.

Cheers, Wayne

 

[Jeff H Young]

send pictures of your progress! It sounds like you put new pipes under the floor to do this? a 3 inch stack in wall. Anyway we would all like to see it after all this head scratching and work!

 

[wwhitney]

Another option, going back to the original post, is to use that side inlet double wye fitting with the side inlet pointing up, very close to where the current upper 3" stack is, flat in the plane of the shower/lavatory drain. You'd put street long turn 90s flat into the two branch inlets, and that gets the LT90 inlet pointed almost perfectly to the toilets. You'd adjust the exact placement of the double wye fitting on the axis perpendicular to the joists to make it line up exactly. (I get an additional 5/16" away from the 2x8 wall for toilets 30-1/2" c-t-c).

The side inlet vent take off is only 2", but that's plenty for the purpose. You could just run it as 2" up to where it joins the shower and lavatory vents, and run a 3" vent for the combined vent through the roof.

That fitting is only available in PVC, while your existing is ABS, any problem using PVC DWV in PA?

Cheers, Wayne

 

[Pulse]

@Jeff H Young
There are a few reasons for all this work. #1) downstairs remodel, #2) replacement of the existing under slab pipes because they are thin wall and do not pass a newly required pressure test, #3) fixing the back to back toilet siphon and other improvements

I just now finished cutting all the concrete. I found no cement, improper use of a sanitary tee, a whole home p-trap, and no p trap on the floor drain which even with the whole home trap still allows sewer gases in..

Finished basement area:

Garage area:

@wwhitney
All PVC is fine.

That is an interesting plan, I will take a better look at it tomorrow.

 

[Pulse]

@wwhitney

The image below is the actual floor plan, as you can see, that circle labeled "main vent to roof" is the actual location in relation to my new 2x8 wall. It is tight.

 

[wwhitney]

The actual location of the existing 3" run through the roof? Are you rebuilding the plumbing wall above, or confining your work to below the subfloor, so you need to tie into the existing 3" below the subfloor?

And if you can provide the dimensions requested, or tell me the last post is to scale and what the grid scale is, I could reconsider the layout based on the new constraints. Also useful would be where the first two joists are in relation to the 2x8 wall.

Does one of your post-slab cutting pictures show that 2x8 wall corner? It looks like there's no reason you couldn't enter that corner in line with the plumbing wall above, and then do a combination of jogging the line towards the top of the page in the wall and moving the slab entrance towards the corner.

Cheers, Wayne

 

[Pulse]

The actual location of the existing 3" run through the roof? Are you rebuilding the plumbing wall above, or confining your work to below the subfloor, so you need to tie into the existing 3" below the subfloor?

And if you can provide the dimensions requested, or tell me the last post is to scale and what the grid scale is, I could reconsider the layout based on the new constraints. Also useful would be where the first two joists are in relation to the 2x8 wall.

Does one of your post-slab cutting pictures show that 2x8 wall corner? It looks like there's no reason you couldn't enter that corner in line with the plumbing wall above, and then do a combination of jogging the line towards the top of the page in the wall and moving the slab entrance towards the corner.

Cheers, Wayne

Yes, that yellow circle is the existing 3" run through the roof.

I will be redoing the plumbing for the 2 back to back baths above.

Are you able to open CAD files?, if so ill draw the joists and send it over, its to scale.

I already demoed the old 2x8 wall, its where that plastic barrier is now.

 

[Jeff H Young]

thanks the only problem I was aware of are the back to back w/c's and you didnt want to lose head room below. much clearer now.
btw we require sch 40 piping and fittings within the building in my code

 

[wwhitney]

Are you able to open CAD files?, if so ill draw the joists and send it over, its to scale.

I use a fairly rudimentary 15 year old CAD program, so I doubt it. But if your floor plan is to scale, and if I have inferred the scale correctly, it looks like the lower stack is roughly alongside one of toilet flanges, and that the center of the existing upper 3" stack is only 3" off the face of the framing of the 2x8 wall. Is that about correct? That makes the it very tight, you effectively have to bring in two toilets to the stack while offsetting the stack and bringing in the shower/lav drain.

Cheers, Wayne

 

[wwhitney]

So, based on the lower stack (slab entry) being ~16" parallel to the joists from the upper stack, and the upper stack being centered 3" off the 2x8 framing, here are my current ideas (it would be easier if you had more room, e.g. if you could move the slab entry to the 2x8 wall after the jog, i.e. the segment the lower toilet is back against). I think I like (1) better:

1) Use the fitting from the original post, as in post #72. From the outlet of the double wye with side inlet, use the appropriate sweep 90 to enter the end of the 2x8 wall at the slope you want. You have room for a street long turn 90, so you can enter horizontally if you like.

2) Enter the wall with two separate drains: one for the far toilet that is dry vented by the upper stack, one for the wet vented near toilet/lav/shower. I think you'd need to enter the wall at two different places along its length, briefly have two different vertical drains in the wall, and then combine them with a wye while jogging if necessary to hit your slab entry.

With the near toilet flange only 3" off the 2x8 framing, space for the fittings for wet venting is really tight. What I came up with is this: make an assembly that is 3" street 60 - 3x3x2 reducing wye - 3" street 60. The wye is rotated so that when the hub ends of the 60s connect to plumb pipes, the 2" branch is horizontal (well, 2% slope). So this assembly go on the bottom of the toilet riser, with the 2" branch pointed perpendicular to the joists to pick up the 2" lav/shower drain. Since the wye is tilted, I get that the angle it makes in plan is 35 degrees, which means it will be moving away from the slab entry (on the axis parallel to the joists), but this angle means that the assembly isn't too long perpendicular to the joists, and the lower 60 hub is still within the 2x8 wall.

Then the other toilet has a variety of ways to enter the 2x8 wall after it is dry-vented by the 3" upper stack. It just has to avoid hitting that jog with 60s on the wet vented toilet. Depending on the relative heights, it might go over the jog and enter right above your slab entry; or it might enter the wall sooner to avoid any crossing in plan.

Cheers, Wayne

 

[Jeff H Young]

I keep looking at the picture dont see a big challenge here but I cant verbalize it as well as Wayne ( nor grasp exactly his plan) Im not great at visualising things from words but as long as you arent expecting to stuff all the piping in the joist bay . OP said as long as he dosent lose head room he is good. since OP relocated stack the pipes hanging down would be confined to less than a 3 ft area. So get busy already ha ha and show pictures of the new and improved!