I have a simple house with a slab foundation and 1 bathroom. I am going to be putting in a new beam that requires a new concrete footer near my existing toilet. The current spacing would be a bit too close so I plan to move my toilet closer to the tub and want to check if my plan for plumbing is roughly correct. My area is Los angeles, CA and under the CA Code that follows UPC. The current design of the house plumbing is shown below - it is a simple 1 bathroom (sink + toilet + bath) with a kitchen sink and then one extra unused drain. Everything goes out to a 4" main sewer that connects near the exterior bathroom wall. I also have the location of a new footer shown that I will be pouring noted as well - everything else is existing/as is.
Here is a closer zoom in to show:
You can see that the footer I'm pouring will be pretty close to the existing toilet cast iron stack, so I'm going to move it a few inches closer to the bathtub and replace the big 4.5" cast iron vent with a 2" ABS vent. The new design I have in mind would look something like below with a wet vent. I believe it uses san tees for the sink & tub connections and a wye for the main sewer.
Does this look acceptable for CA / UPC code? I can't know exactly how the existing kitchen sink ties in to the main sewer and if this affects any of this until I dig up the slab in the bathroom, but should I be concerned about that?
