Any issue using this fitting?

[Pulse]

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

Its hard for me to understand exactly what you are saying, but if the plan is like what you drew before..
https://terrylove.com/forums/index.php?threads/any-issue-using-this-fitting.89707/page-4#post-644192

..i would have to draw it to see, but if you look below at another view of the existing, it may be too much for a change like that..

 

[wwhitney]

..i would have to draw it to see, but if you look below at another view of the existing, it may be too much for a change like that..

That's a very helpful view. The plane of the plastic is basically the face of the new 2x8 wall you are going to build, and you want the slab entry to be within the wall, and you are going to redo the pipes below the slab as necessary? Do you particularly care where the slab entry is within the 2x8 wall, as far as pushing it closer to the block wall?

Cheers, Wayne

 

[Sponsor]

 

[wwhitney]

These are my most recent plans. I am currently trying to tie in that left most side the best way possible. Where the red X is will not be pipe, that long sweep combo will be right up against the double wye, due to space(see first picture).

Going back to the beginning, if you do that, a vertical double wye with a combo up tight to it, and you try to shove the toilet fixture drains as high up as possible in the joist bay, I get these elevations below the subfloor:

4" Toilet fixture drain center line (maybe could be 1/2" higher)
13" Touching hubs of double wye and combo
22" Center line of combo outlet
24" Bottom of pipe
25" After allow for ~ 1" of slope not yet accounted for

If you're willing to give up that much headroom, you can do the above conventional arrangement very simply. You turn the combo outlet to point parallel to the joists towards the block wall, hit a flat 3x2 wye to receive the shower drain, hit a 45 to turn towards the 2x8 wall, then hit a medium turn 90 to go down into the wall, and jog with-in the wall as needed to hit your slab entry.

But I think you can do a flat arrangement where the bottom of the pipes are at most 5" - 6" below the bottom of the joists.

Cheers, Wayne

 

[wwhitney]

OK, here's another flat layout I drew up, it keeps things up high, but I had to use two different levels of horizontal piping (represented as black and purple). It depends on moving the 2x8 wall entry (and presumably slab entry) towards the block wall. The previous drawing I posted isn't feasible because the 2x8 wall is much closer to the closet flanges than I realized. A couple comments:

1) I specified street fittings in places where I'm concerned they are needed to avoid hitting an obstruction: the lower (on the page) pipe hitting the upper (on the page) toilet riser, or at the top of the page hitting the block wall. I made a mistake in the circled part, between the 3" wye just below, the 45, and the medium 90, only 2 out of 3 should be street. (Any 2 will work)

2) For the black pipe joining the purple pipe, the important thing is just that they are parallel to each other and not too close. Then you make up the 45 and 3" wye in the pattern where the two inlets are parallel, making sure the center to center distance on the inlets matches the center to center distance on the black and purple pipe. A 3" wye with street 45 will give you about 5 13/16" center to center; otherwise you want at least 6-7/8" center to center, and you can use a regular 45 and whatever length pipe you need.

Cheers, Wayne

 

[Pulse]

that latest plan is a very cool idea!

it doesnt matter that the purple toilet does not have a vent anywhere close?

thanks for all your help/input

 

[wwhitney]

I figured if I kept at it I would come up with something that would work for you, glad you like it.

The purple toilet is wet vented by the shower/lavatory. There's no distance limitation on the horizontal wet vent I'm aware of.

Cheers, Wayne

 

[Pulse]

I figured if I kept at it I would come up with something that would work for you, glad you like it.

The purple toilet is wet vented by the shower/lavatory. There's no distance limitation on the horizontal wet vent I'm aware of.

Cheers, Wayne

Is something like this possible?, just a straight line picking up both toilets

 

[wwhitney]

PS Zooming in on your last picture, I see that the current fitting under the shower san-tee where the drain goes horizontal is another san-tee, on its back. That's not an allowable drainage usage, san-tee on its back is only for venting under the IPC.

So you are going to need to redo the below floor lav and shower drain, not sure if that was already planned or not. When you do, you have the option to wet vent the shower. You could push the lav long turn 90 horizontal outlet up against the bottom of the joist, and then just bring the shower into the the horizontal lav drain with a flat combo. The shower trap would still hang down a bit below the main piping. And you'd need to verify that when you get to crossing over the white clad pipe (if it is remaining there), you'd still be high enough to clear it after the requisite fall.

If you prefer to dry vent the shower let me know, I have a couple comments.

Cheers, Wayne

 

[wwhitney]

Is something like this possible?, just a straight line picking up both toilets

Good thing you asked.

That was my first thought, but I rejected it because of a rule that says the dry vent for the horizontal wet vent has to be for a lav or shower. However, your question jogged my memory, and I realized that rule is for the UPC. I double checked the IPC, which PA uses, and under it you can use a dry-vented toilet to wet vent another toilet.

So yes, you can do what you propose and then eliminate one of the down stream wyes. Plus everything can be on one level again. Much simpler.

Cheers, Wayne

Edit: there is a bit of controversy about whether the wet-vented toilet can connect to the horizontal drain from above, rather than from the side. Some people feel it is not allowed or will not perform as well. Personally I don't see anything in the IPC prohibiting it.

 

[Pulse]

So you are going to need to redo the below floor lav and shower drain, not sure if that was already planned or not.

Its planned, just not drawn in yet, thanks

 

[wwhitney]

Its planned, just not drawn in yet, thanks

OK, and if you go with the lower toilet wet venting the upper toilet, then the shower/lav drain is not involved in wet venting. In which case there's no issue just using the configuration you now have, except with a combo instead of a san-tee on its back. You may want to raise the shower trap, since the combo is alot taller than a san-tee on its back. And use a street san-tee on top of the combo.

If you're concerned about the possible issue that horizontal wet vents "should" have all the incoming drains on the horizontal, instead of from above, here's a solution.

Cheers, Wayne

 

[James Henry]

I think one of the rules is, everything has to be down stream of a wet vent even if it does have a dry vent. Not saying I'm 100%, just throwing it out there.

 

[wwhitney]

That's a good idea, although not on the right side, because the OP has a 2x8 wall there. (I could argue that the lav/shower drain coming into the left side branch is already downstream of the wet vent, but there's no downside I see to making it unambiguous).

Just replace the "double wye with street 45 in the oulet" with a street wye going into the side branch of another wye. That's got the same connections in the same orientations as the original two fittings, but it moves the shower/lav drain slightly downstream.

Cheers, Wayne

 

[Pulse]

Perhaps this?

maybe increase the 3x wye section from 3" to 4" using 4" x 4" x 3" Wyes

 

[wwhitney]

I don't see an upside to going to 4" before you get inside the 2x8 wall, it just makes the fittings bigger and there's more chance you'll have trouble with room. But if you like 4", you could.

For the toilets, the wyes would be flat, and you'd use a 90 for the toilet riser. A closet bend is a really sharp bend, so I've always assumed this is the one place you could use a medium 90 to go from vertical to horizontal, rather than long turn. Or if you like 4" toilet risers, you could use a 3" x 4" closet bend.

For the dry vent, the wye has to be rolled up 45 degrees so the vent is taken off above center line. Then the angle you need to get to plumb is only 60 degrees, not 90 degrees. You should be able to place the wye so that the rising vent goes into the desired joist bay and you can hit the location you want with the 60.

After the three toilet/vent wyes, if you turn that last wye by 45 degrees CCW, you can eliminate the two 45s on the inlet side, just enter the wall at 45 degree angle, and hit a medium 90. Or if you prefer to enter the wall perpendicular, you can put a 45 between the final wye and the 90.

Cheers, Wayne

 

[James Henry]

If it's possible to install a circuit vent, I would. The down stream toilet might act a little funky without it. it's your call.

 

[Pulse]

@wwhitney

Perhaps perfect?

@James Henry

hmm, that may prove difficult..

All the blue vent lines are basically level with the toilets. The red one is the only option. I have to think of the less intrusive way to tie in there. I have no other holes or open walls to go all the way to the attic

 

[wwhitney]

Perhaps perfect?

The layout looks good to me. At the vent you wrote "45 & 60," but you'll just need the wye you show and a 60 degree bend.

Cheers, Wayne

 

[Jeff H Young]

The layout looks good to me. At the vent you wrote "45 & 60," but you'll just need the wye you show and a 60 degree bend.

Cheers, Wayne

would the uppermost toilet need to tie in downstream of the wet vented one?

 

[wwhitney]

would the uppermost toilet need to tie in downstream of the wet vented one?

I don't follow. The lower (on the page) toilet is dry-vented by the vent just above it in the drawing, and the upper (on the page) toilet is wet-vented by the dry-vented toilet (which is allowed under the IPC, but not the UPC).

Cheers, Wayne