Added an upstairs washer, how to pipe into existing plumbing without having a shower s-trap?

[Amateur 60 Minutes]

On the upstairs floor, I widened a closet to make room for a washer/dryer, and will move back the vent pipe from the front to the back. Plumbing in would be simple if not for the shower drain which I don't want to s-trap. Right now it flows into a sanitary tee in a smooth bend thanks to street 45's on both sides.

If I'm moving that whole design back I need to account for sloping of the horizontal pipe. I'm guessing I need that same 1/4" per foot slope on both the 1 1/2" drain pipe and the 2"? The two pipes would be sloping in opposite directions, would they still fit that sanitary tee placement? I've seen some pictures of 3"x3"x1-1/2" 90 hub elbows with side inlet, but can't find one in 2"x2"x1.5", do those exist?

Thanks in advance for any input.

 

[wwhitney]

Sorry, I'm having trouble reconciling your underfloor photos with the above floor photo. Could you either provide a floor plan, or annotate the above floor photo to indicate which vent you are moving, and where the tub is in relation to what's visible? And what's the story with the ABS vs the PVC?

Cheers, Wayne

 

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[Amateur 60 Minutes]

Sorry, I'm having trouble reconciling your underfloor photos with the above floor photo. Could you either provide a floor plan, or annotate the above floor photo to indicate which vent you are moving, and where the tub is in relation to what's visible? And what's the story with the ABS vs the PVC?

Cheers, Wayne

No worries, I put some labels on the photos. Let me know if you would like some more photos of my predicament.

 

[wwhitney]

OK, hopefully I've got the geometry figured out now. So you want to move the "old vent" to the back wall right next to the "washer and vent"? Looks tight, and you'd have to double drill two more joists.

Each hole in a joist needs to be 2" clear from the top and bottom (well, that's the US building code, you should check if the building code in Canada is different.) And each hole is limited in diameter to 1/4 the joist height (Canadian code; in the US it's 1/3). So if you stick with the top hole in the current joist for the shower trap arm, the bottom hole in that joist would move down/be enlarged by the extra fall required for the trap arm and returning drain to move the requisite distance. Looks like about 3', which would be 6' to and fro, which is 1-1/2" extra fall at 1/4" per foot, which looks like a problem. Maybe you could move the top hole up 3/4" and the bottom hole down 3/4", maybe not. [Or if headroom in the area below is not an issue, you could drop the return drain below the joists.]

Can you move the "old vent" just to the right into that wall? Hopefully without drilling any joists, looks like you have a bit of room in the joist bay to move it back a little, too, if necessary. Moving it to the side would just require changing the length of the short piece running parallel to the joists going into that san-tee at a 45 degree angle from vertical. And the total length change of the trap arm and drain would be much less, so the extra fall you'd get would be much less, so you'd have less trouble with the existing holes in the joist.

Cheers, Wayne

 

[Jeff H Young]

Id bring the washer down into the vericle stack and connect it with wye fitting and leave the rest alone.

 

[Amateur 60 Minutes]

OK, hopefully I've got the geometry figured out now. So you want to move the "old vent" to the back wall right next to the "washer and vent"? Looks tight, and you'd have to double drill two more joists.

Each hole in a joist needs to be 2" clear from the top and bottom (well, that's the US building code, you should check if the building code in Canada is different.) And each hole is limited in diameter to 1/4 the joist height (Canadian code; in the US it's 1/3). So if you stick with the top hole in the current joist for the shower trap arm, the bottom hole in that joist would move down/be enlarged by the extra fall required for the trap arm and returning drain to move the requisite distance. Looks like about 3', which would be 6' to and fro, which is 1-1/2" extra fall at 1/4" per foot, which looks like a problem. Maybe you could move the top hole up 3/4" and the bottom hole down 3/4", maybe not. [Or if headroom in the area below is not an issue, you could drop the return drain below the joists.]

Can you move the "old vent" just to the right into that wall? Hopefully without drilling any joists, looks like you have a bit of room in the joist bay to move it back a little, too, if necessary. Moving it to the side would just require changing the length of the short piece running parallel to the joists going into that san-tee at a 45 degree angle from vertical. And the total length change of the trap arm and drain would be much less, so the extra fall you'd get would be much less, so you'd have less trouble with the existing holes in the joist.

Cheers, Wayne

I threw together some isometrics...

Right now the plan is to just start drilling the first joist next to the green washer pipe as high up the joist as possible, leaving 2" from the top, then work my way along the joists. I don't know exactly where the 1-1/2" shower drain will intersect the 2" pipe, but It should work. The shower trap can also drop 1-1/4" down to help me avoid drilling all three joists with the 1-1/2" pipe.

Thanks a lot for the help gents.

What I have:

What I'm hoping for.

 

[Jeff H Young]

Yea I would leave all the existing plumbing come down through floor with the new work 90 over drill 3 joists then down the wall and conect to the 2 inch line thatis carrying the tub waste with a wye and 45 (upright wye )

 

[Amateur 60 Minutes]

Yea I would leave all the existing plumbing come down through floor with the new work 90 over drill 3 joists then down the wall and conect to the 2 inch line thatis carrying the tub waste with a wye and 45 (upright wye )

You're saying this is the way to go? I thought I needed venting above the shower p-trap?

 

[Jeff H Young]

you already have a vent on existing bath tub right? dont eliminate the vent you have

 

[Amateur 60 Minutes]

you already have a vent on existing bath tub right?

No, the vent that's already there is being removed. The new one is on the left, and the old one being removed is on the right.

 

[Jeff H Young]

there has to be a wall very close to the trap for the bath tub that you are calling a shower. is that changing to a big shower now ?

 

[Amateur 60 Minutes]

there has to be a wall very close to the trap for the bath tub that you are calling a shower. is that changing to a big shower now ?

Yeah, it's an upstairs tub with a shower head. Thanks for the continued help Jeff. I traced the upstairs walls onto the ceiling downstairs. I can put a vent pipe in any of the crosshatched areas more or less. You can even see a 2" hole the plumbers originally drilled to the left of the current plumbing, not sure why.

 

[Jeff H Young]

ok so tear all the tub work out and come up through the top plates with 2 pipes the hole in joist currently can continue to the washer. the tub will be picked up from a second vertical pipe going through plates lining up with wall where tub valve sits with satee below floor for tub trap . should be easily done only thing is youll have to tie the 2 vents together should be easy as well

 

[wwhitney]

OK, I suggest you look at a solution like that depicted by the red line below. That just shows the floor plan path, it doesn't consider the elevation aspects. If everything were in one plane, you'd use an upright combo (barrel horizontal) for your tub vent takeoff, which vertical vent is depicted by the red circle.

The question then is whether you have enough space left right in the picture to fit in that joist bay, from left to right (a) the LT 90 of the tub trap arm (b) the vent takeoff (c) whatever fittings you need to change elevation and (d) the combo for the tub drain to join the drain running perpendicular to the joists.

If you provide the left-right distance between the center line of the the tub trap arm where it comes through the joist and the center line of the drain where it goes back through the joist, as well as the elevation difference between those, I could puzzle out if you can make it fit. And just to confirm, the tub trap arm is 1-1/2" trade size, while everything else in the picture is 2"?

Cheers, Wayne

 

[Jeff H Young]

You do have elevation change to deal with if going waynes route the hole for trap arm is way higher than the hole for the main 2 inch to washer , not sure which way is easier and not quite following his sugestion . I think way I sugested seemed easy. I do see a stud might be in way perhaps a couple eith bends to hit wall with tub vent w my sugested way

 

[Amateur 60 Minutes]

You do have elevation change to deal with if going waynes route the hole for trap arm is way higher than the hole for the main 2 inch to washer , not sure which way is easier and not quite following his sugestion . I think way I sugested seemed easy. I do see a stud might be in way perhaps a couple eith bends to hit wall with tub vent w my sugested way

If you agree what I just drew-up will work, then this has to be the easiest and smartest solution. Moving the tub vent into a wall, and have it tee into the 2" pipe slightly downward while that run connects the washer. The two vents meet in the attic.

 

[Jeff H Young]

sure that works looks like it fits from this angle , that I think is waynes idea.

 

[Reach4]

On #16, is that the laundry standpipe on the right part of your drawing?

If it were a bathroom lavatory, that would change things.

Note that all vertical to horizontal bends must be long sweeps. The shower trap arm will connect via wye, or combo (combination of 45 and wye.)

 

[Amateur 60 Minutes]

On #16, is that the laundry standpipe on the right part of your drawing?

If it were a bathroom lavatory, that would change things.

Note that all vertical to horizontal bends must be long sweeps. The shower trap arm will connect via wye, or combo (combination of 45 and wye.)

Yes, it's a washer standpipe. Thanks for the help regarding the fittings . I'll use a 2" long sweep 90 for the washer part of the plumbing.

Like I said before, I'm going to lower the tub p-trap as far down as I can go. After the p-trap, I'll have a horizontal 90 and then a tee pointing upward for the vent. Since that tub 1.5" piping is slightly higher than the 2" piping, do you think I should use a slightly upturned wye+45 and another 45 to join to the 1.5" after the vent tee? At what point should I reduce the 2" to 1.5"? I was thinking of using a 2"x2"x1.5" wye for the reducing size.

 

[Jeff H Young]

following waynes plan I think youll have to re drill the joist . Not sure i follow the plan in regard to holes in the joist