The Bathroom Remodel that just kept growing... (Question 2 of many - Plumbing Vents)
So, as I've said, we're doing a bathroom renovation, read my earlier post for some more history and fun photos...
Anyway, as I'm tackling the flooring issue (covered in the opening post), I'm also looking ahead to some of the plumbing challenges I can see. I'm pretty comfortable visualizing what supply lines need to go where, but the vents concern me as they might involve some black magic.
If I can see how the entirety of the plumbing should look, installing it piecemeal should be easier...
I need to move the vent stack to a new wet wall, as far to the side as possible to allow room for some supply lines in the shower. I'm trying to visualize the connections. Along the shared wall between the bathrooms and the living room, I will have two toilets; the wet wall will be one of the walls defining a shower between the two toilets. Photos should be at the bottom.
I would think that, ordinarily, you would simply align the vent with the drain lines for the toilets and run the drains into that vent 180 degrees apart. So the vent would normally be 12" from the finished wall separating the bathrooms and the living room. However, since I'm trying to keep the vent as close to that separating wall as possible, everything doesn't line up quite so nicely.
1) Instead of a cross-tee, do I put two tees inline one under the other at the different angles, or do I use a cross-tee with 45's to correct for the angle? Or something different and better?
I also have the issue of spacing. One toilet will be about 20" from the wet wall, and the other toilet will be about 75" from it. I think the first toilet is close enough to the main vent, but I think I will need to put in an additional vent for that second toilet. I should also slope the drain line down (1/4 inch per foot) for those 75".
2) For that second vent, what would that arrangement look like? I'm guessing it would involve a tee and a reducer down to a 2" PVC pipe running vertically into the ceiling. Since that second vent ideally would run in a normal 2x4 wall, I should be able to fit that in there.
3) Both those vents would run up into the attic, where the current vent stack ultimately exits the roof. However, they will come up in different spots from the original. Can I tie these new vents into the original exiting stack? I think I can run a vent horizontally for short distances, and so just jog over with a couple of 90-degree bends
4) Finally, the original stack lines up cleanly on the drain line to the septic tank. What dangers am I facing with moving the stack approximately 5 feet off that line?
You should be able to run the vents as you describe. They should be slightly pitched up to the vent stack.
For the drains,as long as you have the proper pitch under this bath, the drains will be fine. The pipes will need to be dropped down into the room lower then the original setup as they're further away from the stack.