- Reaction score
- port townsend, wa
Okay, so here is the current design for a difficult to plumb bathroom group. The lav is plumbed with 2" and acts as a wet vent for a tub (plumbed w/ 1,5") and a toilet. The trap arms are all within the length limits denoted by UPC and sloped at 1/4". The question I have is about the horizontal 90s that the toilet drain must make in this setup. A 3" pipe drops straight down to a long sweep 90 taking it horizontal, there is a clean out and then it connects to the wet vent with a combo. Right after this combo it has to make one more 90 (a combo with a cleanout) to then shoot straight out of the house and to the sewer. I am aware of the 135 degree rule for horizontal turns (as I understand, after 135 degrees a cleanout is needed, but then more turns can be made). What I don't understand is if the first combo (where the toilet trap arm joins the wet vent) is counted in this 135 degree rule. Obviously these 90s are less than ideal, but the house in question is very constrained with regards to where it can be vented (joist right under a bathroom wall, cathedral ceiling, etc.) I am very much hoping for some advice here as to both the code compliance issue (in WA, so UPC) and your take from first principles. Here is a picture that will hopefully help you understand what is going on. If I am breaking the 135 rule I don't know how I would rectify because I don't even have room between the combos for another clean out. Any help is greatly appreciated. Be well!