3” double fixture

[Bandrusko]

Can you guys or gals help me with a code question. When I bought the house this double santee 3” ties directly into the main stack that goes to my septic, I am thinking of putting a toilet in the room and need to jack up concrete. My question is that this fitting seems improper, I was thinking I would need to replace with a 3” double fixture instead. Please let me know what should be there?

 

[Tuttles Revenge]

Interesting question. A double san tee (DST) isn't against code per se, but it does go against the installation instructions of toilet manufacturers for back to back toilet installations. The reason is that the sudden dump of a lot of toilet water will skip across the DST and push water up the bowl of the opposite toilet and consequently lower the water level in that toilet.

I don't know if the same problem exists if a toilet 20ft away draining down that same side branch would skip across the tee. The waste may have slowed down by that point. Hard to know.

Butt I get the feeling your issue isn't so much that your new toilet is draining down that DST, but that you want to know that if you're already opening up the concrete for a bathroom installation in the slab, would it make sense to get rid of the DST... I would. Plus it would be a good time to get rid of that funky transition between ABS and PVC that were glued together..

 

[Sponsor]

 

[Jeff H Young]

I dont like double santees So Id get rid of it if going into a project if you werent doing any work id leave it alone.
Actually I dont see why cracking the slab is needed but nothing good about the DST

 

[Bandrusko]

Thanks for the replies, so it seems a double fixture is the way to go. I am also getting rid off all the pvc, the rest of the system is abs throughout the house.