Design change due to plumbing
This is more of a "how to get around a plumbing limitation issue" versus a tiling issue. I'm hoping those dealing with remodeling of 2nd floor bathrooms have encountered this problem and can share their solutions.
As part of my plan revisions to move a wall in my shower designs I've spent significant time investigating the joist bays through the can light fixtures on the first floor. I now know the plumbing layout of water sources and drainage it great detail and I finally explained the reason for that the drain venting for the existing jacuzzi tub comes up into the tiled enclosure before heading up the nearby wall.
The wall the current venting is in runs across the top of an I-joist. That also explains the double thick wall in the shower where the valve assembly is since the water source needed a place to get through the sub-floor. To remove the double thick shower wall I'm planning to bring the water lines up the back wall and route them over to the new single thickness wall.
For the tub, since it is in an alcove with windows all around I can't just move the vent to another wall. Wet venting isn't possible since the piping is already at 2 1/2" all the way to the foundation and handles both the tub and the shower so it's already at 4 DFUs ("drain fixture units" for those not in the know for plumbing codes). All I can think of is adding a 4" platform into the alcove to rest the freestanding bathtub on to allow enough space for the venting to take the same path it does today and then waterproof/tile the new platform. If I can create a small overhang on the platform maybe add some LED strip lighting underneath. Though tiling the back of that overhang would be a chore.
Anyone have other approaches they've used?
The issue is to get up into the wall from the joist bay I’d need to cut the top of the TJI joist since the wall is sitting on top of the joist. I wish it was a horizontal run through the studs.