I made a post earlier about this, but it was kind of a jumbled mess . So now I've clarified some things, here it is again.
I'm redoing an ancient basement bathroom/laundry room. This is IPC in North Carolina. The current setup has a long sweep 4in cast iron elbow dipping under the 4in slab and connecting to the city sewer right at the outside wall. The lateral 10ft of 4in (converted to PVC by previous owner) is up high at 78" across the room. The new design will remove that cast iron 90 and instead bury the lateral 10ft under the slab. The vertical portion will be inside a 6" wall. The problem is that the top of the cast iron exit pipe is only 7in from the top of the slab, so it's pretty tight. Also, that main line will be exactly where the toilet needs to be set (there's a window that dictates wall placement). I *think* I have enough room to put a 4-3 combo on its back for the toilet. There will be mortar and tile which gets me another 0.5", but I may end up having to pour an inch or so of cement to raise the floor - would rather not have to do that.
Sizing of the vents is not clear to me. I plan to do a studor vent at the lav. The outer walls are masonry, so venting there is a no go. I'm hiding a dry vent for the laundry in the powder room wall, running laterally thru the ceiling to tie to the 3in vent stack for a bathroom on the main floor. I'm showing 3in bc I would like to also add a utility sink to that laundry line. But I don't know if 3in into existing 3in (with 3 DFU already) is workable. Adding another dry vent to the sky would obviously be a really big job.
For the shower I don't know if it is sufficiently vented by the 4in "wet vent" that is in turn vented by that same 3in stack. (Note there is a 3 by 1.5 san-tee just above that 90 that goes to a tub, but I didn't draw in the lines for the lav and toilet in that main floor bathroom). If I have to, I think there is enough room for a 45° angled san-tee under the shower there to do a vent in the wall. May have to raise shower floor to accommodate that, but that's not as bad as raising the whole bathroom (esp since there will be a pan anyway).
Lastly, I would also like to put a floor drain in here, but I don't know that I have enough venting for all of these fixtures. Not critical, just a nice to have. There's also HVAC in the opposite corner that has condensate - would be great to drain that someplace instead of pumping it outside, but likely not practical.
(BTW, the existing bathroom/laundry here had zero dry vents - house built in 30s. The toilet, laundry and sink were raised up on a rubble/concrete "stage" 24in high. It was so weird)
Any and all feedback welcomed, thanks. Here are some drawings:
I'm redoing an ancient basement bathroom/laundry room. This is IPC in North Carolina. The current setup has a long sweep 4in cast iron elbow dipping under the 4in slab and connecting to the city sewer right at the outside wall. The lateral 10ft of 4in (converted to PVC by previous owner) is up high at 78" across the room. The new design will remove that cast iron 90 and instead bury the lateral 10ft under the slab. The vertical portion will be inside a 6" wall. The problem is that the top of the cast iron exit pipe is only 7in from the top of the slab, so it's pretty tight. Also, that main line will be exactly where the toilet needs to be set (there's a window that dictates wall placement). I *think* I have enough room to put a 4-3 combo on its back for the toilet. There will be mortar and tile which gets me another 0.5", but I may end up having to pour an inch or so of cement to raise the floor - would rather not have to do that.
Sizing of the vents is not clear to me. I plan to do a studor vent at the lav. The outer walls are masonry, so venting there is a no go. I'm hiding a dry vent for the laundry in the powder room wall, running laterally thru the ceiling to tie to the 3in vent stack for a bathroom on the main floor. I'm showing 3in bc I would like to also add a utility sink to that laundry line. But I don't know if 3in into existing 3in (with 3 DFU already) is workable. Adding another dry vent to the sky would obviously be a really big job.
For the shower I don't know if it is sufficiently vented by the 4in "wet vent" that is in turn vented by that same 3in stack. (Note there is a 3 by 1.5 san-tee just above that 90 that goes to a tub, but I didn't draw in the lines for the lav and toilet in that main floor bathroom). If I have to, I think there is enough room for a 45° angled san-tee under the shower there to do a vent in the wall. May have to raise shower floor to accommodate that, but that's not as bad as raising the whole bathroom (esp since there will be a pan anyway).
Lastly, I would also like to put a floor drain in here, but I don't know that I have enough venting for all of these fixtures. Not critical, just a nice to have. There's also HVAC in the opposite corner that has condensate - would be great to drain that someplace instead of pumping it outside, but likely not practical.
(BTW, the existing bathroom/laundry here had zero dry vents - house built in 30s. The toilet, laundry and sink were raised up on a rubble/concrete "stage" 24in high. It was so weird)
Any and all feedback welcomed, thanks. Here are some drawings:
