I am in the process of converting a laundry closet area to a second bathroom, The house is built on slab, and the existing bathroom is in a fairly good condition, so I don't want to break it to tie into the existing line. There is a bedroom adjoining the existing bathroom in the direction of the drain line, and the bedroom closet seems like a best candidate location to dig and tie into existing drain. See the attached image for a crude drawing of the layout
However I am not sure of the exact location of the drain line. My question is, if I trace a straight line from my WC to cleanout, is it safe to assume the WC drain would follow this path, or could there be funkier layouts? The house has a shared wall with the neighbor, but we have individual sewer connections and cleanouts. I am trying to avoid a situation where I dig where I think the drain line would be running only to find it not there due to some turns or something.
However I am not sure of the exact location of the drain line. My question is, if I trace a straight line from my WC to cleanout, is it safe to assume the WC drain would follow this path, or could there be funkier layouts? The house has a shared wall with the neighbor, but we have individual sewer connections and cleanouts. I am trying to avoid a situation where I dig where I think the drain line would be running only to find it not there due to some turns or something.