Does new plumbing waste line have to be underground?
Posted: Sun Aug 19, 2018 8:58 am
Hi all - we are about to start a project where we are converting our detached garage into a mother-in-law unit and adding a new bathroom with a shower, sink and toilet in it. The new bathroom will need to connect to the main sewer line and have a waste line/drain line (not sure what the right terminology is here sorry - I'm talking about the new pipe line that connects the new toilet to the main sewer line). The question is does this new line that will connect to the main sewer line have to be buried underground? We have gotten conflicting information from two plumbers: one said no it can just run under our deck as long as it has the right slope and it's not exposed to the sun; the other said it had to be underground and we would have to dig a trench. We live in San Diego so no frost worries here. It would cost a lot more to have to put it underground so just wondering if anyone knows if there is a code requirement that says it has to go underground? We can easily hide it under our deck to keep it away from sun exposure. Thank you!