3" PVC DWV Wye and 45° Elbow Combo w/ 2" L Side Inlet

[DaveNewhampshire]

Wayne ... first thanks for taking the time for such a detailed reply.

Yes, u-turn is not ideal, but I was hoping to stay in the one joist bay and save boring 2 holes in the joist to the right of the tub drain just to pick up the vertical vent in the stub wall, and losing the 1 1/2 inches in height for the joist flange. I attached a drawing scenario 6 to show what I was thinking.

I can still go with drawing 5 and go over one bay to avoid the 180 degree u-turn, I think I have just enough height, but because I will lose about 2 inches to avoid cutting the joist flange, it will be close.

I do have a 16 inch joist bay, however, where I would like to enter the main house is through the rim board just above the top plate on the house/garage wall (lower left corner of drawings), which is about 4 1/2 inches from the bottom of the flange (or 6 inches down from subfloor). See attached pictureView attachment 82940. This is in a closet back wall in the main house, so I do have the option to drop it down lower into the garage space and go in through a stud, lower, however, this is just to the right of the main house/garage entry door, so it would look a little ugly, but I guess I could frame in a chase around it for aesthetics. I would prefer to stay in the ceiling/floor cavity of the garage if possible.

The tub is freestanding/claw feet, Bain Ultra 6636, and has the overflow and drain above the subfloor, so only the drain pipe coming through the bottom of the subfloor. Shower will be a 60 x 36 pan with a corner glass walls, so no alcove wall to work with unfortunately. The room View attachment 82939right wall is directly over a joist, but if I have to jump a joist bay, I have the 45 degree stub wall I can get a vertical vent in and eventually up the right wall above the bottom plate.

I think I answered your feedback questions, but if not let me know. I may do some more calculations, but if I stay close to the flange on the right joist (which Boise says you can actually cut the i-beam web right to the flange, as long as the flange is intact), I should be able to make the slope work with drawing 5.

I thought I would attach more pics of the pipe locations outside and inside the house. After looking at it more, I guess I could easily drop the pipe a few inches below the joist (and box it in) and come in through the exterior stud bay and closet wall 2x4. I wish I did not cut holes there already!! Although I still think I will have just enough clearance for slope if I stay with original pipe punch through.

 

[wwhitney]

Is that house/garage wall load bearing? If not, you could cut out a section of the upper top plate to drop the pipe 1.5". If it is, it's going to need metal straps reinforcing that large hole in the double top plate.

Is there no way you can move where the tub drain passes through the subfloor closer to the knee wall? What is the tub?

Cheers, Wayne

 

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[DaveNewhampshire]

Is that house/garage wall load bearing? If not, you could cut out a section of the upper top plate to drop the pipe 1.5". If it is, it's going to need metal straps reinforcing that large hole in the double top plate.

Is there no way you can move where the tub drain passes through the subfloor closer to the knee wall? What is the tub?

Cheers, Wayne

Although the house/garage wall is an outside house wall and holds up the second floor rim board, it is a gable end so it does not necessarily carry substantial loads. But since I have already bored a 3 5/8 hole in that location, I want to avoid putting another hole just below the existing one in the joist. I think I will just drop it just below the bottom joist flange and go in through the stud bay/closet wall. I will just have to pull back some more drywall in the closet to make sure there is nothing in the bay now (wiring, pipes, etc.). It will only be a long sweep 3" 90 exposed in the garage and I can easily cover it up.

The tub is parallel to the stub wall, and at a 45 degree angle to the knee wall and side wall in the bathroom. It makes it better space wise with the slanted ceiling, and I needed a conditioned area I can access to put the air pump for the tub. Tub is a Bain Ultra freestanding tub.

Thanks!